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1Back to top Go down    k75 pistons in k100 on Mon Feb 01, 2016 8:01 pm

jjs1234

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Hey!

So before I begin my build thread I wanted to clear out some questions around this.


Since its possible, Ill undertake this challenge. I was planning to drop the engine and do all sorts of fun stuff to it, but I think I'll save that for another time and place.

I just want to get it running.

Anyway, my questions were:

I noticed on schematics that some parts have gaskets (Crankshaft cover, Valve covers [inner and outer], and the Cylinder head). What about the sump cover (as id like to take a look-see to see that everything is good) and timing-cover? Do I RTV these?


Any tips for this modification?


I was planning on buying new k75 pistons @ 60$ ea. (240$) with rings installed and a Main-Bearing set (142$).


Just wondering if I should take into account anything else? Tips? Chain-Timing?

Thanks for any wisdom provided  Very Happy


    

2Back to top Go down    Re: k75 pistons in k100 on Mon Feb 01, 2016 8:40 pm

RicK G

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The only real Gaskets are the head and small cover on the Hall sensors.  The crank and cam covers have neoprene reuseable seals and as for the rest BMW recommend 3 Bond but I use Permatex RTV Blue and have never had trouble.
BMW also recommend replacing the guides and tensioner on the timing chain but I have seen some engines with near 200K and the guides were OK. I would replace the guides and tensioner with what you intend to do as they do seem to get a bit brittle with age.


__________________________________________________
If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

3Back to top Go down    Re: k75 pistons in k100 on Mon Feb 01, 2016 8:57 pm

jjs1234

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RicK G wrote:The only real Gaskets are the head and small cover on the Hall sensors.  The crank and cam covers have neoprene reuseable seals and as for the rest BMW recommend 3 Bond but I use Permatex RTV Blue and have never had trouble.
BMW also recommend replacing the guides and tensioner on the timing chain but I have seen some engines with near 200K and the guides were OK. I would replace the guides and tensioner with what you intend to do as they do seem to get a bit brittle with age.
Ya know whats crazy?

The tensioners alone are more expensive than the entire kit with the tensioners!!

I think I got Permatex Black. Any difference with the colors? 



Cool! Thanks for the advice. 

Im currently looking for info on how to re-align the Camshaft and the crankshaft. I plan on marking them with something white but... yeah.

    

4Back to top Go down    Re: k75 pistons in k100 on Mon Feb 01, 2016 9:59 pm

RicK G

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The Black is OK and would probably do the job but the Blue will cop a lot more heat and has similar specs to the 3 Bond.

Best to put the whole kit in then.
Have you got a manual?


__________________________________________________
If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

5Back to top Go down    Re: k75 pistons in k100 on Mon Feb 01, 2016 10:59 pm

duck

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I think I've used the Permatex Ultra Grey for the water pump and sump cover. No issues.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

6Back to top Go down    Re: k75 pistons in k100 on Mon Feb 01, 2016 11:29 pm

jjs1234

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Wow thought black was better... Well I got the receipt so I'll just exchange it.

As far as the manual goes, I've read one and it was the OEM manual. Didn't mention how to get it aligned though.


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1984 K100
    

7Back to top Go down    Re: k75 pistons in k100 on Mon Feb 01, 2016 11:42 pm

duck

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Just my opinion but "best" is a relative term.  I think it's more binary - it either works or it doesn't. Your bike will not go faster with one or the other.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

8Back to top Go down    Re: k75 pistons in k100 on Tue Feb 02, 2016 12:00 am

RicK G

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jjs1234 wrote:Wow thought black was better... Well I got the receipt so I'll just exchange it.

As far as the manual goes, I've read one and it was the OEM manual. Didn't mention how to get it aligned though.
Have a look at your PM there is a link


__________________________________________________
If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

9Back to top Go down    Re: k75 pistons in k100 on Tue Feb 02, 2016 3:58 am

charlie99

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I have seen 2 versions  of the permatex black

one was cheaper than the other

the dearer one "ultra black " was qualified as very resistant to oil  ...in some places this would be an advantage

but generaly almost all the products will "do the job " ,,,if you don't over plaster the sealing surfaces ...making sure that they seem to seal well almost before any rtv is installed at all


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
    

10Back to top Go down    Re: k75 pistons in k100 on Tue Feb 02, 2016 3:49 pm

Kyle10

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Here's some of the products and techniques I used for my bike's successful resuscitation: 

Products: 
- BMW K100RS STAINLESS STEEL FASTENER KIT
- Battery Cable Kit (4 Gauge) - BMW K
- Premium Silicone Spark Plug Wire Set
- Clymer Manuals BMW K-Series 1985-1997 M500-3 (the best unless you're into forking out the dough for a mechanic's manual) 
- GIBBS® penetrant: this is a restorer's best friend, ever. Will actually make castings look brand new. Amazing shtuff. Ebay or Amazon. 

Techniques/notes:
- Electrikery: check/replace every wire and ground. I swear the majority of elec. problems are simply poor grounds and rotten wires. 
- Mix 10% acetone with Marvel Mystery Oil for rejuvenating salvageable rubber pieces. A quick soak in a ziplock will amaze you. 
- Mix 50% ATF (automatic transmission fluid) with 50% acetone for the best penetrating oil you can obtain. Will get under rust and lift it from the surfaces, where you can wipe/lightly SOS-pad it away. 
- Inspect the rubber boots between the throttle bodies and the intake ports. If they're cracked you must replace them. Do not pass Go, do not collect $200 until you've done this, as your bike will never run properly with shite throttle boots. 
- Euro Motorelectrics is a great company; use them w/confidence.
- http://www.kbikeparts.com/ Seek the wisdom of the Duck; you'll never go wrong w/him. Pore through his many writings and be amazed at how granular this bast...guy gets in making things very, very Kool. 


A lot more to list and suggest, of course. Have fun; you have one of the most underrated bikes, ever. They really shine once they've been given some TLC.


__________________________________________________
1985 K100rt 0052183
1983 Honda VF750 007713 
    

11Back to top Go down    Re: k75 pistons in k100 on Wed Feb 03, 2016 12:09 am

duck

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My .02: Spend your money on radial tires. If you like to ride hard this is the best money you can spend.

Perhaps it's a bit of an exaggeration but radials will turn a Volkswagen into a Porsche.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

12Back to top Go down    Re: k75 pistons in k100 on Wed Feb 03, 2016 3:36 am

charlie99

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duck wrote:My .02: Spend your money on radial tires. If you like to ride hard this is the best money you can spend.

Perhaps it's a bit of an exaggeration but radials will turn a Volkswagen into a Porsche.
agree ...on an rs version




the seating and geometrics of an lt - rt are very different ...still love the good- best aggressive   versions of crossply tyres on an rt-lt  type narrow rim situation ...unless you can upgrade to wider rims and paralever rear end on the rt- lt 8valves  then you will see a vast difference


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
    

13Back to top Go down    Re: k75 pistons in k100 on Wed Feb 03, 2016 3:39 am

indian036

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duck wrote:My .02: Spend your money on radial tires. If you like to ride hard this is the best money you can spend.

Perhaps it's a bit of an exaggeration but radials will turn a Volkswagen into a Porsche.
I'd love to try radials on my '85 K100, but it seems they are like rocking horse poo.

My then fiancé's VW 1200 with cross ply tyres used to do instant lane changes on the Harbour Bridge with a bit of breeze. Even retread radials made a massive difference. Didn't help the power output though. Smile

Bill


__________________________________________________
1985 K100RT Red.  VIN 0028991K100RT    ENG 104EA248523386
1985 K100RT Blue. VIN 0029036K100RT    ENG 104EA25852071
1990 K100LT Black. VIN WB105060310190452
1984 K100RT White. VIN. 0023022K100RT  ENG 104EA32848523
    

14Back to top Go down    Re: k75 pistons in k100 on Wed Feb 03, 2016 3:46 am

RicK G

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Didn't help the power output though. huh


__________________________________________________
If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

15Back to top Go down    Re: k75 pistons in k100 on Wed Feb 03, 2016 5:18 am

92KK 84WW Olaf


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duck wrote:My .02: Spend your money on radial tires. If you like to ride hard this is the best money you can spend.

Perhaps it's a bit of an exaggeration but radials will turn a Volkswagen into a Porsche.

Isn't a Porsche a Beetle on steroids, just 2 extra pots in the back but underneath the same principle?

On the tyres I think of the CB500-4 and the tyres available at the time meant it took work to pull it down into corners on rural roads. It was a pleasure but it took concentration and it always felt like the bike was drifting sideways off line as if the tyres were creeping a little, even with the then Avon Roadrunners.

The K100RT and K100LT however by comparison seem to fall into corners much better and in my case the RT is better on this than the LT. I had the opportunity of a ride on a stock CB500-4 not so long back and it was still the same and not a case of memory nostalgia. I have tried both RT and LT on BT45 after removing the tyres they came on and even that showed an improvement on tyre change alone


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1992 K100LT 0193214 101,000 miles
1984 K100RT 0022575 Baja Red bought 36,000 now 84,100 miles
    

16Back to top Go down    Re: k75 pistons in k100 on Wed Feb 03, 2016 8:57 am

duck

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charlie99 wrote:
duck wrote:My .02: Spend your money on radial tires. If you like to ride hard this is the best money you can spend.

Perhaps it's a bit of an exaggeration but radials will turn a Volkswagen into a Porsche.
agree ...on an rs version




the seating and geometrics of an lt - rt are very different ...still love the good- best aggressive   versions of crossply tyres on an rt-lt  type narrow rim situation ...unless you can upgrade to wider rims and paralever rear end on the rt- lt 8valves  then you will see a vast difference

On my 93 K1100LT switching from bias ply to radials made a WORLD of difference, no more of the wandering feeling on 90 MPH sweepers, MUCH more planted. Also much better handling when really leaned over.

I wouldn't put awider rim on the front of a 2V K, would make the front end less responsive. Not to mention that the extra weight would slow the bike down, both to spin up heavier rims and overall weight.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

17Back to top Go down    Re: k75 pistons in k100 on Wed Feb 03, 2016 9:23 am

Holister

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Greater flexibility in a radial which takes up the unevenness of the road surface better than a cross-ply. Larger contact patch also gives better grip and greater stability giving more control to the rider. Pity there are no more decent radials available for the snow-flake rear wheel.


__________________________________________________
1988 K100RT     VIN No.  0094680
1989 K100RT     VIN No.  0097367 (naked)  
1996 K1100RS   VIN No.  0451808
     Fuel:  95 Octane
Engine Oil: Nulon Full Synthetic 15W50
Gear Box Oil:  Nulon Synthetic 75W90
    

18Back to top Go down    Re: k75 pistons in k100 on Wed Feb 03, 2016 10:11 am

Kyle10

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duck wrote:My .02: Spend your money on radial tires. If you like to ride hard this is the best money you can spend.

Perhaps it's a bit of an exaggeration but radials will turn a Volkswagen into a Porsche.
Hey Duck, 
I know it's somewhere, but can you post your radial 'table' or point the way?


__________________________________________________
1985 K100rt 0052183
1983 Honda VF750 007713 
    

19Back to top Go down    Re: k75 pistons in k100 on Wed Feb 03, 2016 10:49 am

charlie99

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k 1100 lt had rear 3 inch already  and they defiantly feel different than a 8 valve In many respects,  front shocks to start with and paralever rear  but I take your point on that one .


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
    

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