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101Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Dec 12, 2018 5:54 pm

Two Wheels Better


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From vocabulary.com: A motto is a short sentence or phrase that expresses a rule for sensible behaviour, especially a way of behaving in a particular situation. Our motto is 'Plan for the worst and hope for the best', or favourite saying, like 'When life hands you lemons, make lemonade.' A motto is something you might see on a t-shirt or bumper sticker — a short sentence or phrase that has meaning for that person. Some mottoes have to do with politics, religion, or another belief.


Since it's a Moto Guzzi I reckon it can't be reasonably called 'sensible behaviour', so it must fall under the category of 'another belief', or possibly something to do with hoping for the best.

K75kforkurz - Page 3 652573

    

102Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Dec 12, 2018 5:57 pm

Dai

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See that wallaby... K75kforkurz - Page 3 314318


__________________________________________________
'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

103Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Dec 12, 2018 6:11 pm

Two Wheels Better

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K75kforkurz - Page 3 20181036
This was my early Sunday morning view at the Moto Guzzi Club of Victoria's annual Spaghetti Rally back in October. Much red wine, pasta & firewood was consumed. I have some sympathy for the beasts and the men & women who ride them.
K75kforkurz - Page 3 177381


__________________________________________________

1987 K100RS, '89 K100 w/K1100RS engine, '93 Framed K11/K12 engine 'Big Block', '96 K1100RS, '09 K1300GT, '07 K1200R, '95 R100 Mystic & '77 R75/7.

    

104Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Thu Dec 13, 2018 6:08 pm

chris846

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'When life hands you lemons, make lemonade.'


Here in the poetic wilderness of Baaarnsley, our version is,

You have to p**s with the Pr**k you've got.

Great motto though. Maybe explains why I've drunk a lot of lemonade...


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The Longest Lunch
    

105Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Tue Dec 18, 2018 4:56 pm

chris846

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Oh dear #2

Thought I'd best have a look inside this mystery engine, and found this...
K75kforkurz - Page 3 01611K75kforkurz - Page 3 02011

Maybe those rags that had been encouragingly stuffed into all the orifices when I bought then engine, hadn't been there all the time. Maybe.
Anyway, after scientific analysis of the strange contents of cylinder No 1, turns out it is definitely CRUD.
Things weren't too bad after it all cleaned up, but the honing marks on the bores are hardly visible, and there's a bit of corrosion on the deck where it looks like the, erm, rainwater has started to work its way out of the cylinder past the head gasket.

K75kforkurz - Page 3 02210

Also, this is the exhaust cam. Am very familiar with this type of hard surface failure, as a result of owning oilhead boxers:
K75kforkurz - Page 3 00310

And lastly, here's the measured valve clearances. I say 'clearances', what we've really got here are 'avoidances' - whoever let the bike get to this stage obviously didn't want the valves to carry on opening. Maybe it was to prevent any more rain and crud getting in? (the clearances are circled - and read as you look at the cylinder head)

K75kforkurz - Page 3 02610

This whole engine looks like a bit of of a car crash. I'll sling it back together, with a new cam, and a WHOLE NEW set of shims, but with the original gasket. If it makes more than half a fart compression when it's all done, I'll show my *#@* on **@#* town hall steps **##* ~@*** Joan Collins too.



Last edited by chris846 on Tue Dec 18, 2018 5:25 pm; edited 1 time in total


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106Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Tue Dec 18, 2018 5:02 pm

charlie99

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whilst you have it apart chris , perhaps a valve lap would be appropriate  to clean up the seats at least ?

good luck


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OK75kforkurz - Page 3 Au-log10
    

107Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Tue Dec 18, 2018 5:13 pm

chris846

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Hiya Charlie, how's summer?

I took the valves out and surprisingly the valves and seats seemed pretty much okay underneath the crud. There was a goodly layer of oil and carbon underneath everything (you can see this in bores 2 & 3 in the pics), so I wonder if it had stood for a few years on its sidestand, before the rain, hail, locusts etc. found their way in. 
K's eh - inbuilt self-preservation?


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108Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Dec 19, 2018 5:18 am

chris846

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Thinking on - maybe those silly valve clearances were due to crud being trapped between valve and valve seat? Must investigate before I spend the Christmas drinking budget on a set of custom made super thick shims. (Many thanks to my 2 dogs for providing me with this idea during this morning's walk. Very intelligent dog, the Labrador)


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109Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Dec 19, 2018 5:40 am

RicK G

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Quite likely Chris BMW recommend doing the shims before the spark plugs are removed due to the possibility of carbon bits getting caught in the seat and making a mess of the job.


__________________________________________________
"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats."  from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

110Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Dec 19, 2018 4:17 pm

chris846

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Well it looks like the dogs called it. Checked the valve clearances again and they're a lot more normal. Still need to swap a few shims though - it's the exhaust valve clearances that have opened up. Weird about the dogs though, I always thought that their special talent was eating up their own puke.

Anyway, I went hunting for valve shims and opened up an old K100 engine that I bought ages ago just to use as a jig for making some headers. It had supposedly come from a running bike with Starship Enterprise mileage:

K75kforkurz - Page 3 00112

How bad is that? And why is it always No 1 cylinder that fills with crud?

Anyway, did you spot the No 2 exhaust valve -

K75kforkurz - Page 3 00311

Now that really is weird. I mean, how can you run a bike with....this?

K75kforkurz - Page 3 00511


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111Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Dec 19, 2018 4:48 pm

Dai

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@chris846 wrote:Now that really is weird. I mean, how can you run a bike with....this?
Easy Very Happy . I burnt out both exhaust valves over 200,000 miles on the V1000G5 and only got round to replacing them each time when I got a bit peeved with the lack of performance. No damage to the valve seat in either case. I've always suspected that unleaded fuel had a part to play in the failure.


__________________________________________________
'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

112Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Dec 19, 2018 5:32 pm

chris846

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So that's just a burned out valve, not some zombie pizza-eating mystery motorbike gremlin?


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113Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Dec 19, 2018 8:25 pm

RicK G

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Nope just too much heat due to unleaded fuel as Dai has said


__________________________________________________
"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats."  from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

114Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Thu Dec 20, 2018 5:13 am

chris846

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That's food for thought then. The engine has the lighter crank and the 12 rivet aux shaft. The casings are marked '90' so it's a least a 1990 model. Weren't they supposed to be unleaded-proof by then?

There's also at least one replacement valve already in there - No 4 exhaust. No 1 & No 3 are well on their way to joining No 2

And you're right - the No 2 valve seat from the burned valve doesn't look bad at all.


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115Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Thu Dec 20, 2018 8:41 am

RicK G

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The seat wont burn it's stellite and has good heat dissipation. The over heating will start when the valve starts riding and doesn't touch the seat so the heat builds up. It probably never had the valve clearances checked since it stopped going to the dealer when warranty ran out.


__________________________________________________
"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats."  from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

116Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sun Dec 23, 2018 1:34 pm

chris846

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Not so big end.

After finding Tutenkhamun's remains inside No1 cylinder, I decided to have this mystery engine apart altogether.
No1 big end shells were so-so, No2 were awful, No3 were like new. Have a look at these sorry pics:

K75kforkurz - Page 3 00113
K75kforkurz - Page 3 00312
K75kforkurz - Page 3 00410

At first I thought of oil problems - something's happened to overheat the rod and cap, and that's worn the shells too.
The mains are fine btw. Checked the crankshaft journals - big end and main journals are within spec, even poor old No2 (Haynes manual figures). Although the bottom end looks a horror story (which I first thought it was) everything's actually within spec and not bad looking, apart from the No 2 rod and shells.

A test reassembly led to No2 rod actually being tight on the crank - what? How is that with such worn shells? After swapping parts and head scratching, it turns out the big end bore in the No2 rod is undersize.

Bear with me, I could be losing the plot, but the measured bore in the No2 rod is 40.91mm. Haynes spec is min 41.00mm. No1 rod is slightly small at 40.98, No3 rod is fine. This matches the state of the shells - they have worn because of the small bores in the rods.

I went foraging and dug out some other rods (K100) they are all min 41.00mm.

So how does a rod shrink?

The bores are circular - measured at 90' so they don't seem small due to distortion. The mating faces of the caps show no sign of being machined down. The No2 rod is very tight when assembled, even with this amount of wear (the No2 shells have lost about 1.5 thou thickness radially) - so how on earth can it have left the factory like this - if that's what happened?


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117Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sun Dec 23, 2018 3:17 pm

Dai

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It was a Christmas engine. Fritz drank too much gluhwein.


__________________________________________________
'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

118Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sun Dec 23, 2018 3:44 pm

Two Wheels Better

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Hence the ground away engine number...someone rode it like they stole it!


__________________________________________________

1987 K100RS, '89 K100 w/K1100RS engine, '93 Framed K11/K12 engine 'Big Block', '96 K1100RS, '09 K1300GT, '07 K1200R, '95 R100 Mystic & '77 R75/7.

    

119Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Thu Dec 27, 2018 11:44 pm

charlie99

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I would be reconning that some one did the heat the exhaust pipes up till they are glowing red , from dead cold ...ie full stick till it stops

such a shame

good luck with the repairs mate ….k100 rods k75 pistons  , but you might need a new crank ?


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OK75kforkurz - Page 3 Au-log10
    

120Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Fri Dec 28, 2018 12:20 am

MartinW

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With the blueing on number 2 rod looks like overheating.
Regards Martin.


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K75s Hybrid
    

121Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sat Dec 29, 2018 1:21 pm

chris846

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Ah, mystery solved...
K75kforkurz - Page 3 00811
K75kforkurz - Page 3 00910
 No, this isn't a pair of ex-Valentino Rossi conrods, the two engraved numbers - should - indicate matching conrods and caps (ARE YOU LISTENING PREVIOUS OWNER?).
Turns out that somebody decided to reassemble the bottom end after shuffling the components. This is what caused the 'tight' No2 conrod big end and the overheating/blueing. Unbelievably, putting 46 with 46, and 5 with 5 gives a pair of rods with correct big end bore sizes. Who'd've f*##*ng thought that!
The mystery had been bugging me, and I must have been stupid (again) not to have checked this when I first came across the tight rod. I guess you just assume that the absolute fundamentals don't get overlooked, even by novices.
As well as this, the main bearing caps weren't in the correct order either (they have stamped numbers) Not such a serious problem as the line boring and milling must be done to the same datum.
Lesson learned. I always lay components out in the correct order on disassembly and don't usually check for numbers or marks that might or might not be there. From now on I'll double check. Every day is a school day.
Just in case I felt any of my usual 'mistakes happen' sympathy about the previous spannerman, here's the bolt (top in the picture, versus the correct item underneath) that was performing the minor, not at all important function, of holding the timing chain sprocket on the front of the crank:
K75kforkurz - Page 3 01110

What is this, 'war on the crankshaft'...?

The crank is hardened, so it must have taken a bewildering amount of mechanical indifference to wind what is obviously an engine mounting bolt into the end of the crank. I guess somewhere there is a K75 with the engine hanging on.....I daren't think.


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122Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Jan 02, 2019 6:30 pm

chris846

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Kids, if you smoke and eat butter, here's what your arteries will end up looking like...
K75kforkurz - Page 3 00512The bits of gauze that you can actually see, are where the crud has already fallen off. I've not come across the later, plastic pickup before, but I have this awful feeling that it didn't start its life concave...


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123Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Jan 02, 2019 7:22 pm

Arlina

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@charlie99 wrote:I would be reconning that some one did the heat the exhaust pipes up till they are glowing red , from dead cold ...ie full stick till it stops

such a shame

good luck with the repairs mate ….k100 rods k75 pistons  , but you might need a new crank ?
It wasn't me, first let the engine warm up Smile

https://www.youtube.com/watch?v=0dvruYzv-u8


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K75kforkurz - Page 3 Eu-log10  K1100RS/LT - R1200RT - R1100RS (RIP) - Cagiva SST 350 Ala Verde
    

124Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Jan 02, 2019 7:23 pm

Point-Seven-five

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Oh, my!  That is disturbing! 

Another job added to my winter to-do list so I can sleep soundly when riding season rolls around again.


__________________________________________________
Present:
1994 K75RT
1991 K100RS

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

125Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Jan 02, 2019 7:48 pm

RicK G

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Chris it's very simple. It's world v idiots so far world 0 idiots infinity


__________________________________________________
"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats."  from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

126Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Jan 02, 2019 8:00 pm

Woodie

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Fokkin' 'ell Batman!  I am in a perpetual state of second guessing the work that I do on my lovely K - did I get everything back together according to the diagram? did I remember to do the seventh step of the secret handshake or am I just thinking I remembered? - THAT is just low down back yard butchery (especially the bolt).  At least you get to make things right and we get to learn.

After a lifetime in construction there is just nothing that will surprise me.  Not saying I've seen it all by any stretch.  The male of the species is profoundly capable of reasoning out the most diabolical solutions in my experience.


__________________________________________________
1985 K100RT
52667
"Keep your stick on the ice.  We're all in this together."  Red Green
    

127Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Jan 02, 2019 8:55 pm

Two Wheels Better

Two Wheels Better
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It's all good, and you need only have faith,  in the chicken bone dance.
bounce


__________________________________________________

1987 K100RS, '89 K100 w/K1100RS engine, '93 Framed K11/K12 engine 'Big Block', '96 K1100RS, '09 K1300GT, '07 K1200R, '95 R100 Mystic & '77 R75/7.

    

128Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Thu Jan 03, 2019 5:07 pm

chris846

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"It's all good, and you need only have faith,  in the chicken bone dance."


Yes of course, and these kinds of shoes is often donned, too....


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129Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Thu Jan 03, 2019 6:00 pm

Two Wheels Better

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Funny that, and a few days ago that guy reappeared. I caught it, deleted the three new abstract 'sneaker' posts, and Crazy Frog deleted his account. It was someone, this time, calling themself Amberfrancis. What a bizarre way to push your message.


__________________________________________________

1987 K100RS, '89 K100 w/K1100RS engine, '93 Framed K11/K12 engine 'Big Block', '96 K1100RS, '09 K1300GT, '07 K1200R, '95 R100 Mystic & '77 R75/7.

    

130Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Thu Jan 03, 2019 7:07 pm

RicK G

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He popped up on one other forum I frequent and got the same treatment. It's hard to imagine that the type of advertising really gets anywhere especially when almost everyone that is net savvy just ignores them.


__________________________________________________
"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats."  from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

131Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Fri Jan 04, 2019 5:40 pm

jayk47

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This whole thread has made for epic reading! fun and educational!  Very Happy

    

132Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sat Jan 05, 2019 12:59 pm

chris846

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Hi Jay, I haven't even started yet!
So far it's all fantasy - nothing has really been tried and tested in the real world, so all my bright ideas and convincing-sounding technoguff are floating on unchallenged. The real work will come when I fire the thing up and set off down the road and it catches fire/falls in half/steers into a ditch or, worst of all, is boring.


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133Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sat Jan 05, 2019 1:28 pm

92KK 84WW Olaf

92KK 84WW Olaf
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@Dai wrote:
@chris846 wrote:Now that really is weird. I mean, how can you run a bike with....this?
Easy Very Happy . I burnt out both exhaust valves over 200,000 miles on the V1000G5 and only got round to replacing them each time when I got a bit peeved with the lack of performance. No damage to the valve seat in either case. I've always suspected that unleaded fuel had a part to play in the failure.

I did exactly that on a Fiat 128 years back, of 1981 vintage. Towed a boat and figured the leaded petrol I paid for had the tank at the petrol station filled with regular. Head off and one valve identical to that one but otherwise engine was perfect.


__________________________________________________
1992 K100LT 0193214 Bertha Alaska Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 58,645 now 91,850 miles
1983 K100RS 0011175 Fricka 29,495 miles Damn K Pox
    

134Back to top Go down   K75kforkurz - Page 3 Empty K75forkurz on Sat Jan 05, 2019 3:58 pm

Tom FKR

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There seems to be some kurzcomings  with exhaust valves in some engines????


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1993 K75 Slightly Modified
2010 BMW F650GS Twin
1992 R100R
    

135Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sun Jan 06, 2019 7:24 am

jayk47

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@chris846 wrote:Hi Jay, I haven't even started yet!
So far it's all fantasy - nothing has really been tried and tested in the real world, so all my bright ideas and convincing-sounding technoguff are floating on unchallenged. The real work will come when I fire the thing up and set off down the road and it catches fire/falls in half/steers into a ditch or, worst of all, is boring.
Ha.. Thats the only way to have it boss! go big or go home, or in the case of a bike what you modified yourself, into the hedge. 

Keep it coming, will be waiting for further installments in the Yorkshire frankenbrick .. 

j


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Learning how to repair the bike i broke......
    

136Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Feb 06, 2019 4:13 pm

chris846

chris846
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Just about to start finish welding the frame, now that I've sorted out all the various lugs and whatnots it needs to mount modules, brake fluid reservoir, battery etc.
Thought I'd post a few pics to show it side by side with a standard K75 frame (less the cafe-racered lopped off back end, naturally, ahem) The engine/gearbox mountings are lined up together:
K75kforkurz - Page 3 01010
K75kforkurz - Page 3 01710
K75kforkurz - Page 3 02012K75kforkurz - Page 3 02611

And here's one of the design team - you can see their careful approach to things in the way they've chosen to modify their own sofa:
K75kforkurz - Page 3 00114


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137Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Feb 06, 2019 9:13 pm

charlie99

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@chris846 wrote:
And here's one of the design team - you can see their careful approach to things in the way they've chosen to modify their own sofa:
K75kforkurz - Page 3 00114


aww sweet pups, wouldn't hurt a fly in this mode


nice frame works chris


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OK75kforkurz - Page 3 Au-log10
    

138Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed Feb 06, 2019 10:56 pm

Woodie

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I've seen that same innocent look before after much the same sofa mod.  Sadly it was the one we stored for the mutt in our living room.  Lovely work on the frame Chris.  TIG?


__________________________________________________
1985 K100RT
52667
"Keep your stick on the ice.  We're all in this together."  Red Green
    

139Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Fri Mar 22, 2019 2:15 pm

chris846

chris846
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Yep, TIG for the frame. The welding set gave up half way through and had to be replaced. Things just keep getting smaller don't they? the new one is half the size of the old one, and much better.

Anyway, the frame is now fully welded. Here's some boring pics of the various mundane brackets and stuff to hold the ECU and things. 

K75kforkurz - Page 3 03812
K75kforkurz - Page 3 04012
K75kforkurz - Page 3 04211
The second photo shows the extension to the steering head, which was necessary for the longer length of the KTM yoke stem.

Now then, back to something much more bizarre, in keeping with my normal theme. Can anyone see what's going off here?
K75kforkurz - Page 3 04510


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140Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sat Mar 23, 2019 12:42 am

tinyspuds

tinyspuds
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I’ve been quietly pleased with how my (with much help from all on here) re-commissioning project has been going . But having read this thread I just feel... inadequate. Fantastic vision Chris and showing interest in the decorating project at the same time indicates a master at work.
BAlance
Stu


__________________________________________________
1985 BMW K100RT + Hedingham HUB and LL’s.
2007 HD883 Sportster. Bobbed and bettered.
1954 Royal Enfield 350 Bullet. Original.
    

141Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sat Mar 23, 2019 6:54 am

Woodie

Woodie
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 Can anyone see what's going off here?

You started re-framing the walls in your garage/shed/shop but then got distracted with "more important" things like customising K's?


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1985 K100RT
52667
"Keep your stick on the ice.  We're all in this together."  Red Green
    

142Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sat Mar 23, 2019 8:41 am

Laitch

Laitch
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@chris846 wrote:Now then, back to something much more bizarre, in keeping with my normal theme. Can anyone see what's going off here?
A hybrid throttle body assembly.


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1995 K75T 68,000 miles
K75kforkurz - Page 3 Usa-lo10
    

143Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sat Mar 23, 2019 8:43 am

Dai

Dai
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Damn but I had to look at that for a while before it finally dawned on me.

Edit: Laitch got in a few seconds before I did.


__________________________________________________
'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

144Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sat Mar 23, 2019 9:09 am

Laitch

Laitch
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robmack fabricated one for his retro K75. His was a converted K1100 assembly.



Last edited by Laitch on Sat Mar 23, 2019 7:56 pm; edited 2 times in total


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1995 K75T 68,000 miles
K75kforkurz - Page 3 Usa-lo10
    

145Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sat Mar 23, 2019 9:25 am

chris846

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Woodie got it!

Seriously (bad choice of word, I know) yep I nicked the cable quadrant and throttle cable bracket off some 1100 throttles, only reason is that the OE cable routing would foul the new airbox. Love playing with these Ks. Well spotted guys, happy to be in the company of such a tiny section of the population, who know and discuss these fantastically obscure things just as naturally as everyone else knows the days of the week.

Got a set of K1100 throttles lying around now...
And 3 (out of 4) K75 pistons that were unavoidably cheap on Ebay recently.
And a K100 that hasn't been standard since 1987.


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146Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Mon Apr 01, 2019 12:57 pm

chris846

chris846
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Anyway, here's a little bit of progress, followed by some first class stupidity:

The Mark IV clutch release arm (Mk IV was developed to incorporate the additional feature of actually working, unlike its predecessors)

K75kforkurz - Page 3 01711

Half a day spent routing clutch and throttle cables. The weird thing sticking out front is the fairing bracket, with uppy-downy, inny-outy, twisty adjustment:
K75kforkurz - Page 3 02013

And now my favourite bit. I pondered this for ages (like days) wondering how best to access the idle speed adjustment screw - now that I've grafted on bits from a K1100, the screw is underneath at the rear (bad design). I thought maybe a ratchet ring spanner might do it, but there's not enough room. Today, I settled on modifying the screw and cable quadrant so's it screws down from the top. This is cerebral stuff, and it takes a certain type of brain (which not everyone has) to come up with a skilful and elegant solution, as befits this engineering work of art. With a casual sigh I was about ready to show those Germans how to do it properly, again.
K75kforkurz - Page 3 02110

Then my mate stuck his nose in (pictured in the background) and twisted the throttle for me. He needs to die.
K75kforkurz - Page 3 02211


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147Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Fri Apr 26, 2019 3:36 am

chris846

chris846
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(In case not everyone is familiar with the 4v K, the idle speed screw appears by magic when you twist the throttle. I now know this)

Another bright idea that came to nothing:

The 'standard' 3 spoke 4.5" rear when fitted to the paralever back end that I have used on this project, has a left offset of 2mm, with no shims fitted. I use the 2 mudguard mounting dowels on the gearbox as a datum to measure this - assuming that BMW must have put the mudguard inline with the rear wheel.

K75kforkurz - Page 3 02612

The wheel I intend to use is the 5 spoke 5" rim from a K1200. At the mo, I only have a 5.5" rim, with a 180 tyre fitted. This needs 2 shims (=5mm) to clear the swingarm. The measured offset when fitted is 12mm to the left. The visual effect of any offset is doubled i.e. things like the tail unit/number plate seem 24mm closer on the left.

Even with a 5" rim (when I eventually get one) which I hope I can use without spacers, the left offset will still be 7mm. 

So I decided to see if I could offset the frame to the left by a similar amount - y'know, saw the lugs off like y'do. It would be really convenient if the drivetrain had a centre of gravity over on the left side of things too. And then I could claim that I've butchered the lugs for scientific reasons, rather than the truth, which is that I just want a fat and unnecessary back wheel.

Sooo, I did this:
K75kforkurz - Page 3 02111
K75kforkurz - Page 3 02014

Which is to say that I built up the drivetrain as much as possible (no fluids though) and balanced it on a lengthwise rod. The COG is somewhere around 20mm right of the centreline (I forgot to mention that the 2 mudguard dowels in the gearbox align with the centreline of the OE frame - this is something I've previously measured)

There's right side assymetric stuff still missing too - the rear shock, caliper and disc, and the coolant header tank and contents. The radiator is missing, but that's pretty much central.

I was a bit surprised that it was so far off. I've all sorts of thought about this - the paralever (assymetric on the right) must be a good deal heavier than the monolever that the K75 should be fitted with. Maybe the K100 is better balanced - and sawing off the front (left biased) cylinder threw the COG over to the right on the '75? Or, maybe BMW know a hell of a lot about what they do, and this right side COG offset works out nicely with the rotation of the longitudinal crank?

Anyway, I'm off babysitting today, so the distant stare of the uncommunicative old guy in the park, won't be anything for the mums to worry about.


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148Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Sat Apr 27, 2019 7:36 pm

chris846

chris846
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Since the previous post, I remembered that somewhere I'd got a 5" rear from my R1100s kicking around. The was the 'loaner' wheel thast became a spare after I fitted a 5.5" for better tyre choice. At one time, there were 5 of us with R1100esses and this wheel has been a bit of a tart over the years. I always hoped it'd come back with a decent tyre on it, or maybe even a disc. No such luck.

Anyway, it bolts up okay (no disc or spacers sandwiched inbetween) with 5mm left offset. That'll do for me. This is the shed remember, and, when confronted with the cack results of our slapdash workmanship, we invent a type of earthy pragmatism, completely bogus of course, and dismiss obvious shortcomings with statements such as "it's nowt that'd bother a blind man on a galloping horse". There's usually a few similarly easily satisified oafs kicking around, who'll readily confirm such comfortable falsehoods, with affirmative grunts. Like they're real experts or something.

This is a view NOT seen by a blind man on a galloping etc.

K75kforkurz - Page 3 02112

At this point (nice wheel, but no back brake) the existence of a couple of R1100s rear discs buried somewhere amongst the spares graveyard became relevant. When uninterred, one of them even had a very convenient little plastic bag of the special mounting bolts taped to it. This type of organisation and foresight is definitely not our handiwork, it invites our awe. We'd rather think of it as serendipity, than the example of good practice that it clearly is. The earthy pragmatism isn't real, remember? We're just slipshod.

The matching caliper doesn't fit though. Not yet anyway.


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149Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Wed May 01, 2019 5:11 pm

chris846

chris846
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Well the left offset of the rear wheel is now just 3mm after a bit of work on the paralever pivot pins. So I'm happy with the wheel, 'cept it's got this disc mounted inconveniently on the wheel itself. I can't use the K disc, because the wheel offset isn't designed for a disc sandwiched between wheel and hub. However, the R-series disc-on-the-wheel, and the K disc, all seem to be in the same place in relation to the 2 caliper mounting lugs on the bevel housing. To check this, I put a R bevel and a K bevel side by side on the marking table, and I'll be b******d if I can see a difference.
K75kforkurz - Page 3 00413
K75kforkurz - Page 3 00611
 The problem for me is that the R bevel has a modified cover, with a relief to clear the mounting bracket for the matching caliper. 
K75kforkurz - Page 3 00710

It's a problem, because I can no longer use the K caliper. This is because the R disc has a smaller OD and a narrower track and needs the matching caliper. It would be nice to just use the R bevel, but BMW didn't foresee my intentions and the R bevel has no facility to machine a bore to take the shock bottom mounting ( the tempting-looking boss on the casting which you can see in the second picture is for a sensor, and so hasn't got the beefed-up wall thickness of its K-series forefather) So, I machined lots of important metal off the R caliper mounting bracket and fitted it to the K bevel like so..
K75kforkurz - Page 3 00812

Which as you can see from the gap between the shock bottom mount and the bevel casting, brought me to the next problem, which was the caliper and the shock battling for the same bit of space. It worries me that I never get fed up with this pointless, self-induced, chain of problems.

Sixteen washers later, and a solution is in sight. I can space the caliper over to the left, so's it clears the shock, and this also allows me to use a caliper mounting bracket that hasn't had all that important metal milled off in order to clear the relief in the bevel cover that isn't there. (Edit: I also made a 15mm spacer to raise the spring and spring platten of the shock to assist with clearance too)
K75kforkurz - Page 3 01310
All I need to do is mill 10mm off the disc mounting posts on the wheel, so's the disc can follow the caliper on its leftwards journey!

Why?
Why why why oh why?


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150Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Thu May 02, 2019 5:30 pm

chris846

chris846
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Another day....

Ended up machining a whopping, destroy-my-wheel-why-don't-I, 15mm of the disc mounting posts on the R1100s wheel. I could have gone another 5mm before the caliper started to clout the spokes. Made 2 15mm spacers for the caliper and it looks like this:
K75kforkurz - Page 3 00213
There's now plenty of clearance between the shock and the caliper, so I reduced the 15mm platten spacer in the bottom of the shock to 5mm. The other advantage is that the disc is no longer worryingly close to the paralever rubber bellows (as BMW designed it, ahem).
The whole setup now looks acceptable, even 'designed' (which it most definitely wasn't) My pal was less impressed though, he said that I'd now "gone and made it non-standard". WHAT?


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151Back to top Go down   K75kforkurz - Page 3 Empty Re: K75kforkurz on Thu May 02, 2019 6:07 pm

chris846

chris846
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Here's the shock too. It's a WP unit from a KTM something-or-other. I've used them before on the Madass, and before that on my K100. Back then it was a 'needs must' choice because my Koni Dial-a-Ride (never any good for me) had died (actually, it was killed) and I needed a cheap replacement. These WP units seem to be very cheap on Ebay. The best thing about them is the outstanding quality, plus they're rebuildable and very versatile. They take a standard 2 1/4" coilover spring (I use rates around 250 lb/in) and have adjustable comp and rebound, plus about a mile of threaded adjustment for ride height on the cylinder body. You can vary the oil weight (standard is 2.5 wt) to get the shock exactly right for your own needs. Plus, if you replace the nitrogen filler plug with a Schrader valve you can fill it to the required 10 bar or so with a mountain bike shock pump, using good old air, drawn free from the atmosphere. They seem to come in all sorts of combinations of cylinder length and piston rod length, and you can fit gazillions of spacers under the piston to give any sort of overall length and stroke length you want. The 'special' tools that you need to strip them aren't that special and can easily be made. 

K75kforkurz - Page 3 01112
The only real hurdle is that you have to make up a rod end bottom mounting to replace the clevis that they usually always have (WP list a rod end alternative on their fiches, but it's probs v. expensive)
K75kforkurz - Page 3 01210



Last edited by chris846 on Thu May 02, 2019 6:17 pm; edited 2 times in total (Reason for editing : illiterate)


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