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Engine smokes at startup - Valve stem seals?


Lone_RT_rider

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So, my 1999 R1100RT with 105K miles has always been a bit smokey, but lately it's progressively getting worse. I won't even start up the bike in the garage unless the tailpipe is pointed in the right direction. My first instinct is the valve stem seals. I have changed those in old american V-8 engines before (pressurize cylinder, press down valve spring with correct valve spring tool, pull keepers, , remove spring and replace seal. Then reverse removal process for installation). Is the process basically the same?

 

I have not done a compression check, but she runs damned strong. Also, I am not leaving it on the side stand, it gets left on the center stand most all times, even at work.

 

Any ideas?

 

And no, I don't want to start an oil thread. :D

 

Shawn

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So, my 1999 R1100RT with 105K miles has always been a bit smokey, but lately it's progressively getting worse. I won't even start up the bike in the garage unless the tailpipe is pointed in the right direction. My first instinct is the valve stem seals. I have changed those in old american V-8 engines before (pressurize cylinder, press down valve spring with correct valve spring tool, pull keepers, , remove spring and replace seal. Then reverse removal process for installation). Is the process basically the same?

 

I have not done a compression check, but she runs damned strong. Also, I am not leaving it on the side stand, it gets left on the center stand most all times, even at work.

 

Any ideas?

 

And no, I don't want to start an oil thread. :D

 

 

Afternoon Shawn

 

On the old high mile BMW boxers it is usually the rings that cause start-up oil burning.

 

You can still have good compression but weak oil control rings.

 

Valve seal replacement is as you wrote above.

 

Try parking bike on the center stand to see if start-up oil smoke gets better.

 

 

 

 

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Try parking bike on the center stand to see if start-up oil smoke gets better.

 

Thanks for the quick reply. I only park the bike on the center stand, so I am probably seeing the best it can get at this point. Replacing rings is not something I have time for currently, so that will go low on the project list. I will just keep adding oil. :)

 

Shawn

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Before you park on the center stand, while still sitting on the bike, lean the bike over to the right. Put the bike on the side stand, then put it up on the center stand.

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So, my 1999 R1100RT with 105K miles has always been a bit smokey, but lately it's progressively getting worse. I won't even start up the bike in the garage unless the tailpipe is pointed in the right direction. My first instinct is the valve stem seals. I have changed those in old american V-8 engines before (pressurize cylinder, press down valve spring with correct valve spring tool, pull keepers, , remove spring and replace seal. Then reverse removal process for installation). Is the process basically the same?

 

I have not done a compression check, but she runs damned strong. Also, I am not leaving it on the side stand, it gets left on the center stand most all times, even at work.

 

Any ideas?

 

And no, I don't want to start an oil thread. :D

 

 

Afternoon Shawn

 

On the old high mile BMW boxers it is usually the rings that cause start-up oil burning.

 

You can still have good compression but weak oil control rings.

 

Valve seal replacement is as you wrote above.

 

Try parking bike on the center stand to see if start-up oil smoke gets better.

 

 

Is the problem generally that the oil control rings are worn, or gunked-up with deposits?

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Any other symptoms?

If not...oil cheap.

 

Just that all that oil will probably take out the catalytic converter over a while. Other than that, she just keeps plugging along. :)

 

Shawn

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Any other symptoms?

If not...oil cheap.

 

Just that all that oil will probably take out the catalytic converter over a while. Other than that, she just keeps plugging along. :)

 

Shawn

 

At 105k your cat is probably already DOA.

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Any other symptoms?

If not...oil cheap.

 

Just that all that oil will probably take out the catalytic converter over a while. Other than that, she just keeps plugging along. :)

 

Shawn

 

At 105k your cat is probably already DOA.

 

:lurk:

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So, my 1999 R1100RT with 105K miles has always been a bit smokey, but lately it's progressively getting worse. I won't even start up the bike in the garage unless the tailpipe is pointed in the right direction. My first instinct is the valve stem seals. I have changed those in old american V-8 engines before (pressurize cylinder, press down valve spring with correct valve spring tool, pull keepers, , remove spring and replace seal. Then reverse removal process for installation). Is the process basically the same?

 

I have not done a compression check, but she runs damned strong. Also, I am not leaving it on the side stand, it gets left on the center stand most all times, even at work.

 

Any ideas?

 

And no, I don't want to start an oil thread. :D

 

Shawn

 

My .02 Canuck. Have we all considered how the oil was checked? You know, the old oil dance check thread that is on here somewhere?

in short, if the warm oil bike wasn't put on the side stand for 5 minutes and then put on the center stand, then the oil level could read low and the owner would add too much to bring it up in the site glass. = high oil level and oil burning off out the tail pipe.

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Shawn.....my RT did the same thing after the mileage crept up there. It was worse when I parked at work because I had to put it on the side stand (sloped parking lot). It used to fire a good puff of smoke on startup every afternoon. Less so in the mornings after being on the center stand overnight, but still a little. Mine used to puff smoke when riding hard as well, and that is almost always attributed to the rings starting to wear out. Compression and leak down tests were always within spec when I checked it.

 

I thought about looking into it further, but figured it wasn't worth the headache for the small amount of oil I was losing. When I parked it for good at about 135K miles, it was still barely burning any oil between changes. I think it only takes a few drops to get that mosquito cloud on start up

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My 04 RT is using a bit of oil too but not much visible smoke. I just changed the valve seals and tried the tool with the magnet in it. You whack the tool and it catches the keepers on the magnet inside. That part worked great. Since the engine is sideways, installation with the other side of the tool is a no go. I used the five zip tie and water pump pliers method to compress the springs. The engine has 48K on it and the valve stems have a bit of play and the valve faces some marking. They still seal well but the combustion chamber shows too much carbon buildup. I have only run a few hundred miles with the new seals so I can't tell if I am using less oil yet. I will probably run the motor like this until the valves start leaking or some other issue requires a tear down. The bike runs very well on 93 octane fuel with very little knock( using the AFXied O2 sensor manipulator). Mike

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I had a 2000 1100 RT with 136,000 miles. I rebuilt the engine, It was not a good idea.

 

First I found the piston rings were all lined up on the top of the piston both sides.

 

End gap was just out of spec.

 

Compression test showed above spec because carbon build up.

 

004-L.jpg

 

Cylinder looked good, still had hone marks, probably never broken in.

 

I took the heads with new BMW guides to a machine shop. They did the valve job, charged me $500 and said it did not need the guides.

Rod bearings were not worn at all. This is the firs time I saw cracked (broken) rod caps.

 

 

 

003-L.jpg

 

Crankshaft play was .004", right at the limit.

 

003-L.jpg

006-L.jpg

 

I think the bike was lugged for the first 100,000 miles before I bought it. It always had oil changes at 3,000 miles from new.

 

Pistons and bore were still in spec. It was burning the "window" (16 oz)full of oil in 800 miles.

 

I bought a Kawasaki Versys 650 to ride while the RT was down.

 

After the rebuild, the clutch splines were really worn. Almost ready to strip.

 

010-L.jpg

 

Hard to photograph, but just paper thin left.

018-L.jpg

 

 

Ended up buying a NEW 2012 R1200R camhead. Once I had the new R, the RT and Versys just sat around. Should have used the money I put into the engine on the new bike.

 

David

 

Pics are photobucket and will disappear later this year.

Edited by David R
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Maybe it does not belong here, but these are the splines at 100,000 miles when I bought the bike.

 

Just shows a heavy hand on the throttle was part of the wear problem.

 

007-L.jpg

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Maybe it does not belong here, but these are the splines at 100,000 miles when I bought the bike.

 

Just shows a heavy hand on the throttle was part of the wear problem.

 

 

Morning David

 

Or possibly just repositioning the clutch disk on the trans input splines in a different clocking position at first check.

 

Once the splines wear into a specific match-up in the clocking position, if that match up is changed, then the resulting spline mismatch can greatly accelerate the future spline wear until the contact wear evens out to become full contact again. (even one spline tooth position off is as bad as 180 degrees off).

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Thanks for the posts David.

 

My theory of what finally did in my RT is very similar to where I think you were heading with the crank shaft runout. My clutch wore out at 100k miles. I went to replace it and found heavy spline wear. I chose to rebuild the transmission with a new main shaft thinking that the original lasted 100K miles, so will the replacement. 35k miles later that new transmission shaft stripped out. My theory is that the crank shaft bearings were getting sloppy, which accelerated the wear on the transmission splines. No proof of course, just a theory. I still have the motor sitting in the back of the garage, but at this point I'm not sure I care enough to put a dial indicator on it to properly check.

 

Sorry Shawn....didn't mean to hijack :grin:

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Sorry Shawn....didn't mean to hijack :grin:

 

It's all good man. :) You know I enjoy all things mechanical. Now if you would have tried to hijack this thread talking about software code..... we'd be feud'n. :rofl::dopeslap::stir::shake:

 

Shawn

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So.....whatcha gonna do? Going to investigate further or leave it alone? :lurk:

 

If it would have most likely been the valve seals, I would have done that. But since everyone seems so convinced that it's the oil rings and that my engine will probably self destruct in 37.6 seconds after I re-assemble the thing, I am probably just going to keep starting it outside the garage and adding oil. :)

 

They will have to sell that bike after I'm dead anyway. Let the next person deal with it. lol

 

Shawn

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I had a .045 ring end gap in my airhead. I bought a set of rings for .5 mm oversize piston and filed them until the speced .014" clearance.

 

Its been there since 1993. Still doesn't smoke unless I shut it off hot on the side stand.

 

I always shut the bike off, lean to the right, then put on side stand. I still do it with my camhead although it makes no difference.

 

Rings are easy if that is the fix. A leakdown test will help decide.

 

I have some spare valve guides... :rofl:

 

Daviod

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