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1Back to top Go down    Leaky Intakes - rough running on Mon Nov 08, 2010 2:25 am

Ned

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So you think that you don't have any air leaks ? These are pics of my intake pipes that looked great and I though didn't need replacing.



Ater removal and inspection :



The only way to tell is to do the test using propane or something liquid that is a little less dangerous.

Another place many people miss are the injectors them selves. The O rings (the only thing that forms a seal) perish, crack and start to leak. So, squirt some liquid down the injector holes and replace those O rings. I pay about 50 cents for one from my local garage.


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Ned

05/1986 (K55) K100RS Motorsport (Europe), Production Code: 0503, 110k km, VIN:0140519 (SOLD)
1976 Honda Goldwing GL1000 (naked)
1997 BMW K1200RS red, VIN: WB10544A1VZA22667
    

2Back to top Go down    Re: Leaky Intakes - rough running on Mon Nov 08, 2010 8:28 am

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One question. How did you get Skippy to hold the intake spigots for you while you took the picture? Damn smart 'Roo he is! Smarter than Sonny.

    

3Back to top Go down    Re: Leaky Intakes - rough running on Mon Nov 08, 2010 7:40 pm

Ned

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wonders of technology Smile tiny Sony camera with close up lens, just right for a single paw operation. Even fits in the pocket, sorry, pouch. Smile


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Ned

05/1986 (K55) K100RS Motorsport (Europe), Production Code: 0503, 110k km, VIN:0140519 (SOLD)
1976 Honda Goldwing GL1000 (naked)
1997 BMW K1200RS red, VIN: WB10544A1VZA22667
    

4Back to top Go down    Re: Leaky Intakes - rough running on Mon Nov 08, 2010 10:42 pm

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How much air gets past the upper intake spigots to have an effect on the overall smoothness and running? I'd think the post-throttle body spigots would be the real problem with fuel mixture leaning out...I know I need to have a good squiz at mine since they're an unknown quantity at the mo'. Better to just order them and do them anyway as it's a fair bit of effort to just get at them. I have significant and uncomfortable vibes at about 3200 and again at 4200-4400 rpm that are not tyre balance related. Everything else appears to be in order, mechanically. My quick check with propane (unlit, of course) showed a very very slight varying of the idle.

    

5Back to top Go down    Re: Leaky Intakes - rough running on Tue Nov 09, 2010 12:52 am

Ned

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[quote]
@Two Wheels Better wrote:How much air gets past the upper intake spigots to have an effect on the overall smoothness and running? I'd think the post-throttle body spigots would be the real problem with fuel mixture leaning out...
I don't think so. I believe that it is ALL unmetered air will add to the problem. The mixture is determined by total air that is sucked in through the metering device and the temperature of the engine. Taking this to the end conclusion, any leaks that bypass this between the valves and after the metering device is bad news.

I know I need to have a good squiz at mine since they're an unknown quantity at the mo'. Better to just order them and do them anyway as it's a fair bit of effort to just get at them. I have significant and uncomfortable vibes at about 3200 and again at 4200-4400 rpm that are not tyre balance related.

I got rid of my 3200rpm vibrations simply by plugging all leaks including injectors and crank case vent tube.
One of the real problems is the connector between the two air intake boxes.

Everything else appears to be in order, mechanically. My quick check with propane (unlit, of course) showed a very very slight varying of the idle.
You won't get much variation in idle, but I think that it will make a difference once you remove all the leaks, they all add to the problem.


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Ned

05/1986 (K55) K100RS Motorsport (Europe), Production Code: 0503, 110k km, VIN:0140519 (SOLD)
1976 Honda Goldwing GL1000 (naked)
1997 BMW K1200RS red, VIN: WB10544A1VZA22667
    

6Back to top Go down    Re: Leaky Intakes - rough running on Tue Nov 09, 2010 1:28 am

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I will have to consider that the lower spigots could be in as bad (or good) condition as the uppers given that they're likely the same age, and I recognise that the air is metered after the airflow metre inside the airbox has determined the correct mixture for the 'current conditions'. The fact is that any place for air to leak, from the mounting points inside the airbox to the blind plug atop the upper half, etc., is then a potential air leak. I have always been very careful to be certain all potentials are looked at when working in the area too. The crankcase vent hose on my bike is in pretty good nick (no evident age cracks or other signs of perishing - first thing I looked at) and I have a new spare on the shelf as well as a set of injector o-rings available. Did you use a generic but thin hose clamp or did you purchase the use-once clamps from BMW?

The bike motors along at virtually all other rpms with not a hint of vibes, and even improves with higher rpm. Which part of the airbox do you reckon contributes? The outer edge of the actual air filter is the point between the upper and lower airbox halves. I've included the images for you here.


    

7Back to top Go down    Re: Leaky Intakes - rough running on Tue Nov 09, 2010 4:08 am

Ned

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thanks for the drawings. I will reply in a little bit because I like to give you as much info as I have. I may have a few more pics as well.

The bottom line is, and please keep this in mind, that air is sucked by pistons and it will come from any place that offers the least resistance.

I changed all rubber components and I did find that the bottom number #4 was really bad. All injector or rings were screwed and it took a lot of pulling to get them out. The rubber was simply welded to the head.

However, if you take a closer look at the picture, you'll see that the lower manifolds are rubber coated metal. you may find that they are fine. Consider using a sealing agent (not silicone) to help seal and to lubricate the rubber during the assembly process.

Finding narrow clamps was a real problem. In the end I give up and used a combination of sealant and nylon cable ties, yes cable ties.

I will reply in detail soon.


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I reserve the right to voice my opinions on any subject known to man
Ned

05/1986 (K55) K100RS Motorsport (Europe), Production Code: 0503, 110k km, VIN:0140519 (SOLD)
1976 Honda Goldwing GL1000 (naked)
1997 BMW K1200RS red, VIN: WB10544A1VZA22667
    

8Back to top Go down    Re: Leaky Intakes - rough running on Tue Nov 09, 2010 5:37 am

Ned

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Which part of the airbox do you reckon contributes? The outer edge of the actual air filter is the point between the upper and lower airbox halves. I've included the images for you here.

I think that points 1 and 2 need checking. Anything around the filter is below the meter so it shouldn't matter.

A few things to consider:

Before you start please check the compression (hot). It may explain a few things.

To dismantle:
you will need to remove both boxes. No choice there.
When you are there check:
a. temp sensor,
b. the fan
c. fuel pressure regulator connections, and if you have time,
d. check the air flow meter.

Unbolt the throttle bodies and remove the injectors. It is possibly a good time to check the injector spray pattern, but this scan be done at any time.





To assemble:
a. careful when you bolt the manifolds to the head. Torque them down EQUALLY. As throttle bodies fit inside the manifolds they have to be aligned vertically.
b. I've used a sealant between the head and the manifolds to reduce any chance of leaks (no silicone).
c. manifold hose clamps need to oriented correctly. From memory the bolts interfere (can't remember what with, sorry). I suggest that you take a pic to make sure they go back correctly.
d. fitting the top spigots is no problem but you will find it a tight squeeze to get the air box pushed on the spigots.
e. I've decided to use nylon cable ties on the top spigots because finding a correct hose clamp is near impossible. The standard Tridon or equivalent are just too wide. The ties worked well for me. I dare say that the BMW clamps will work, but you will need a tool to squeeze them tight.

You will probably need to balance the the throttle bodies when you are done.

I think that that is all. Good luck.


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I reserve the right to voice my opinions on any subject known to man
Ned

05/1986 (K55) K100RS Motorsport (Europe), Production Code: 0503, 110k km, VIN:0140519 (SOLD)
1976 Honda Goldwing GL1000 (naked)
1997 BMW K1200RS red, VIN: WB10544A1VZA22667
    

9Back to top Go down    Re: Leaky Intakes - rough running on Wed Nov 10, 2010 2:10 am

K-BIKE


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That is truly excellent stuff, well documented and really useful!
Regards,
K-BIKE

    

10Back to top Go down    Re: Leaky Intakes - rough running on Sat Dec 25, 2010 4:36 am

charlie99

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woohoo a really good write up ned ....thanks ...ill be doing this shortly

i have a a k100rt ...with not much care taken over the last few years .... symptoms are backfires/pops sometimes and vibrations at 3200 and up .clears as revs increace further past 4000 ...no 1 cylinder is running a little lean compared to the others (by examination of spark plug colour after a 400 k trip )
i was looking for this info ....thanks mate ...cheers


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

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

11Back to top Go down    Re: Leaky Intakes - rough running on Mon Jan 10, 2011 6:43 pm

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I've purchased (from Motobins & Motorworks) the four rubber airbox sleeves, the rubber spigots to the cylinder head (one of which is visibly perished), have eight new injector seals, all 12 of the special clamps which are sized 48.5mm, 50mm, the four screw-type lower clamps, and an oil vapour bypass hose at the ready as well. With all of this rain we're currently experiencing in SE Queensland I look forward to getting into the garage very soon. This is gunna be fun! I'll post my progress.

    

12Back to top Go down    Re: Leaky Intakes - rough running on Mon Jan 10, 2011 6:47 pm

Ned

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camera ready? we will look forward to it. I am curious if your throttle bodies remain in balance when done.


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I reserve the right to voice my opinions on any subject known to man
Ned

05/1986 (K55) K100RS Motorsport (Europe), Production Code: 0503, 110k km, VIN:0140519 (SOLD)
1976 Honda Goldwing GL1000 (naked)
1997 BMW K1200RS red, VIN: WB10544A1VZA22667
    

13Back to top Go down    Re: Leaky Intakes - rough running on Fri Jan 14, 2011 7:36 pm

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I've managed to tear into the bike in the garage while waiting for the waters round Brisbane and environs to recede a bit. The intake rubbers were my target, as the bike has exhibited some vibration at certain rpm (3200 and about 4100-4500) that became slightly annoying on the longer open road cruises which have dominated my life over the past six months or so. As I said before I've gathered up the necessary bits and got cracking. I'd previously checked ignition timing, wheel balance, throttle body sync and general frame to engine and gearbox bolt tightness. I'd observed a slight hairline crack in one of the rubbers and verified a potential leak by using a propane bottle pointed at the rubbers with the engine running (no flame) and observed a mild fluctuation in the idle. The bike now has over 100kms on the odo and the rubbers looked original from the outside. It was time.

My experience was much the same as Ned's and I won't bore you with the details about how to get stuck into the fairing panels and such because you've all got different models. Suffice to say that the tank and fairing panels have to come off to make it easier to access the bits. I use a special fuel clamp on the fuel hose to avoid leaks. Remove the two fuel hoses from the tank or the fuel rail. It's a good idea to run the bike prior and unplug the four-wire connector that clips to the underseat computer to avoid having excess fuel under pressure when you do slacken the clamps to the fuel lines. The bike will stop after a mo' when the fuel pressure drops. I also bag and tag all screws, clips and smaller components to make it easier when reassembling the pieces. I also have a pad and biro to draw myself a map of vacuum and fuel hose routing, or just for reassembly notes. You may not get to it the same day and coming back into the garage after a lay off and realising the maze of pieces before you don't all look familiar is a sinking feeling. All back together and what's this extra bolt or spring or clip for? I hate that.

Once you can see the things you're going for it's best to start removing the airbox halves by unscrewing the band clamps and fiddling the airbox pieces out and away to the right hand side. The top half which contains the L-Jetronic housing can be left to dangle, though I wired it up to take strain off the electrical wiring leading to it. The bottom half has two Allen head bolts holding it to the block inside. Take out the oil bypass hose. Remove the fuel pressure valve from the back of the throttle bodies by unscrewing two Philips head screws. Unscrew the TPS from the end of the throttle bodies. It's easy to set it up again later on 8V models. Take out the accelerator cable by loosening the cable's chain and gear at the right hand handle, then freeing the small barrel at the TB end. Remove the 'choke' cable in a similar fashion, at the left hand side handle control, take off the plastic cap and remove the large screw holding down the thumb control. The cable end pops out easily. Remove the injector rail and carefully wiggle the injectors out of the cylinder head, being extra careful not to drop any debris down the holes leading to the intake valves. I stuffed a small piece of clean cloth into each hole after carefully cleaning out the rubber and dirt that accumulates there. The injector seals, as Ned or others have said, might be 'welded' to the aluminium head. Mine were and had to be gently rocked back and forth until they broke free. Unscrew the clamps that secure the rubber spigots to the cylinder head - you might have to jump round to the right hand side to access one or more of these screws, depending upon how they were attached by the P.O. or the factory, if original. Tilt the entire upper airbox and throttle body set to the left and wiggle it out from under the frame, sliding them a bit toward the back of the bike once the throttle bodies are free of the rubber spigots. It's a tight squeeze but having taken off the bits at the back it comes out fairly easily.


All four of the upper rubber sleeves had visible hairline cracks and one was split right through, falling apart in my fingers when I pulled it free of the airbox upper. The lower spigots were in better nick except for one which had a visible crack in it. They've all been binned.


Clean the throttle bodies with carburettor cleaner and a soft toothbrush, being sure to squirt some of that juice into all of the fine orifices. It's amazing how much accumulated gunk there can be on these faithful old soldiers. I lubricated the return springs, throttle and 'choke' cable arms, and replaced the old vacuum caps with newies too.

Now you can begin the task of removing the upper airbox from the throttle bodies and giving the whole mess a good cleaning. I used carburettor cleaner so it does not attack the rubber bits, leading to potential swelling, like brake parts cleaner might. The upper rubber sleeves are clamped down with one-time-use clamps that come off fairly easily with a twist of an appropriate tool like the pinch clamps I used in the photo. Perhaps BMW have a special tool but I didn't bother with it. I'd bought the proper sized clamps to replace them with and because they are a small width they may not be easy to find generically. Some people have used cable ties (zip ties) with success. The uppers are 50mm and the lowers are 48.5mm. This is important because the rubbers are stepped to fit their respective housings. The lower spigots use thin width screw clamps and are reusable, but I bought new ones just in case too. The throttle bodies were covered with dust that had attached itself to the grease and oil that accumulates over time. I used an old toothbrush and gently cleaned out and thoroughly hosed down with carbie cleaner the TB set, including the air screws and vacuum holes. Surprisingly, with a good eye and some fine thickness gages I could see and measure that the throttle body butterfly plates were opening at about the same rate as one another in the early stages.


It's said that cleanliness is next to godliness. I hope that makes the bike run better!

The alu cylinder head needed a good scrubbing (stuff the intakes with rags) as there was a bit of corrosion. After the intake spigot surfaces were made clean and smooth I screwed down the new rubbers using a tiny dab of non-silicon sealant and tightened them to spec. These are 6mm Allen heads in soft aluminium and don't need more than 8 NM or 6 ft/lbs of torque. Position the clamps but don't tighten them as later on you will need to be certain they clear the area around the throttle bodies like the throttle cable arm and other bits. Replace the rubber on the airbox top half and position the pinch part of the clamps facing the bike's left hand side, but don't snug them just yet. You will see why when the bits are all back on. Slide the upper airbox half back onto the TB set and wiggle the assembly back into the new intake spigots, being sure you don't squash down the edges of the new spigots. A very small dab of grease on the inside of the rubbers works a charm here, lubrication being the essence of making pleasure in our lives. It's a wiggly, fiddly thing to do, but with patience and a few curses of praise to the Teutonic gods, you should get the whole mess fitted back into place. Now with the ancient pinch clamp pliers tighten the clamps, after you've made sure the airbox half and the TB set are resting comfortably and lined up correctly. Mine had to be forced a bit to be aligned. Now work out the best position for the screw-type clamps to be in and tighten them down. Replace the TPS and adjust the it 'til you hear a click (you can come back to this later on by just setting the screws so they don't fall out), replace the fuel pressure valve and vacuum hose, vacuum caps and fuel lines. Install new o-rings on your fuel injectors, both upper and lower ends, replace the fuel rail (a tight squeeze, this) against the injectors and bolt it down, being sure the top o-rings don't squash out and distort and that the square retaining clips attach to the injectors and the fuel rail correctly. Again, a small dab of fuel soluble grease works a charm for allowing the injectors with new, fat o-rings to slide into place.


The 'hundred year old' tool makes a comeback! Those eight clamps aren't easily pinched tight any other way.

Refit the accelerator and 'choke' cables, being sure you get the full range from open to close, adjust 'choke' cable freeplay, be sure the clamps are tightened sufficiently once again and in the correct position so as not to interfere with the workings of the cables, and replace the airbox halves and be certain the large clamps are tight after giving the lower airbox half a thorough cleaning out, renew or reuse the air filter, fit the oil bypass hose (I replaced mine - had tiny cracks in it visible only by pinching it - a potential air leaker), and refit the fuel lines. Refit the computer and any other items except for the side panels and such just yet. There is always something you want to re-check before buttoning up the works and realising you need access to that little tiny thing way down the bottom under that thing that's right in the way and your big fat hand is too big for the space you've got left! I set the TPS by switching on the key, making sure it was not holding the throttle plates open, and listening for the click when I opened the throttle. I fine tune it once I've taken a test ride. With battery connected and all components given the once over I levered the thumb control, pulled in the clutch lever, and pressed the starter button. It lives!

I've never had my bike start instantly and settle down into a such a smooth, steady (but slightly faster than before) idle. I believe this to be because the old, perished rubbers allowed air leaks and are now tight and sealed up. After a five minute warm-up at idle I gave the throttle a coupla quick blips. She revved up nicely but consistently hesitated a tad, but the throttle snaps back to idle like never before. I was careful to route the throttle cable in the most direct line under the tank and around the airbox. I moved the TPS a notch and tried again a few times until the hesitation was gone, so I tightened the screws to the TPS. Reaching for my electronic syncro tool I realised the 9 volt battery was flat, it was time for a beer, and a bit late as my music was still playing at daytime volume in this quiet neighbourhood. I closed the garage door, turned off the music, switched off the lights and went inside for the night. Man, my legs ached from the all day up and down (I don't have a workbench for the bike) and the strain from the cement floor. I needed that beer. Today I am checking the throttle bodies for sync and refitting the panels. I've been away working all week and a nice ride will do me a world of good.

Later that day...a cuppa tea and a 9 volt battery for my syncro techno gizmo in hand and I've warmed the bike to operating temperature. The idle is smooth and unhesitating. I whack the syncro thingy onto the individual vacuum ports and discover that #3 is just off the others a smidge. A blade width of the screwdriver or two anti-clockwise and she's spot on, inline like a good citizen. A few good revs and she settles to a nice steady, sewing machine idle of about 1000 rpm +/-. At revs the TB's are goose stepping in unison like old pros in a marching band. Synchronising them is a bit more complicated and I'm feeling glad I don't have to touch 'em. The feel on the road is good, smoother and crisper than it's been in yonks. The vibes have dissipated. I like a definitive fix.

Next up, sloppy timing chain.

    

14Back to top Go down    Re: Leaky Intakes - rough running on Fri Jan 14, 2011 9:59 pm

club_c

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Nice work TWB. Took me back to mid Spring last year when I did the exact same thing. I developed a leak between the head and manifolds after reassembly, so had to pull that part up again, but found I could do it without removing the tank, the parts on the left could be removed quickly after removing the airbox on the right. A tight fit as you said, but certainly do-able (twice actually.... )

    

15Back to top Go down    Re: Leaky Intakes - rough running on Sat Jan 29, 2011 10:23 pm

charlie99

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good work twb ....thanks for the post ...gives me confidence ....


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

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

16Back to top Go down    Re: Leaky Intakes - rough running on Sat Jan 29, 2011 10:51 pm

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It's a fairly straightforward and easy job for the average skilled, backyard, shadetree mechanic to accomplish. The timing chain/guide/tensioner was an easy one too. Now she's good to go for another coupla hundred thousand Ks!

    

17Back to top Go down    Re: Leaky Intakes - rough running on Mon Feb 14, 2011 5:14 pm

club_c

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TWB, what is the p/n for these intake rubbers? I've just found mine are also leaking... can't seem to find them on Realoem.com

    

18Back to top Go down    Re: Leaky Intakes - rough running on Tue Feb 15, 2011 2:45 am

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They're shown under 'engine' and with the airbox apparatus, not with intake or fuel injection. Here's the link:

http://www.realoem.com/bmw/showparts.do?model=0503&mospid=51751&btnr=11_1776&hg=11&fg=20

You can often re-use the lower clamp but you'll have to replace the two sets (2x4) of clamps on the upper rubber sleeves. They are 48.5mm and 50mm in diametre and when you're in there you'll see why. The lower clamps aren't pictured here but are BMW part number 11 61 1 460 940 (pictured with the throttle bodies). Motobins sell most of these bits and for less than BMW, as usual.

    

19Back to top Go down    Re: Leaky Intakes - rough running on Sun Mar 13, 2011 7:05 pm

Oldgoat

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Great info guys! This is basically what I'm doing on mine now and TWB that is the same method I used to check/sync the butterflies. Great minds think alike, lol!

OG

    

20Back to top Go down    Re: Leaky Intakes - rough running on Tue Mar 15, 2011 2:38 am

K-BIKE


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Fantastic effort, solid gold info.
Regards,
K-BIKE

    

21Back to top Go down    Re: Leaky Intakes - rough running on Wed Jun 15, 2011 7:12 pm

ian1200


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will have to look at mine

    

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