Need help again, oil smoke from right exhaust

[Prez]

Some related info here. http://www.thegsresources.com/_forum...d.php?t=125631

Basically, went through the carbs, after re-installing them I was trying to fine tune. Just as before the carb cleaning, #3 still seemed to be running rich (headpipe was cool enough to hold). So I went about leaning out that cylinder, eventually ran the fuel pilot in to a lightly seated position. Revved it up to 4k for a several seconds to burn out the unburnt fuel, suddenly it starts pouring oil smoke out the right side.

Fear is, that I leaned #3 out too much, thus overheating it quickly & scoring the cylinder or effectively "melting" the rings or valve seals there. Planning to do a compression check this evening, if I get home from my side job in time. Possibility #4 could be the culprit, since the compression was low there before, like it might have had a ring problem.

[80GS750]

oooh ouch man...

that really sucks...

hope you didnt do too much damage

[TheCafeKid]

Some related info here. http://www.thegsresources.com/_forum...d.php?t=125631

Basically, went through the carbs, after re-installing them I was trying to fine tune. Just as before the carb cleaning, #3 still seemed to be running rich (headpipe was cool enough to hold). So I went about leaning out that cylinder, eventually ran the fuel pilot in to a lightly seated position. Revved it up to 4k for a several seconds to burn out the unburnt fuel, suddenly it starts pouring oil smoke out the right side.

Fear is, that I leaned #3 out too much, thus overheating it quickly & scoring the cylinder or effectively "melting" the rings or valve seals there. Planning to do a compression check this evening, if I get home from my side job in time. Possibility #4 could be the culprit, since the compression was low there before, like it might have had a ring problem.

Easy enough to fix man! Pull the head, new seals, pull the jugs new rings. Seriously, its not as tough as it sounds

[Prez]

Just fired it up for a few seconds, #3 was firing right off (fuel pilot still bottomed out), and no smoke. Leaves me to think it's valve seals, a compression check later will confirm. Either way, if I have to pull the cylinders, I'm doing both, just might do the Wiseco 850 kit while I'm in there. Had planned to bump one or two of the 3 engines to 850 anyway, really depends on the cost of stock replacement rings & valve seals vs the Wiseco kit.

Oddly enough I build $20k diesel engines, but the thought of tearing into a roller bearing engine is intimidating to me.

[80GS750]

when i did a hone and stock rings in my 1000 it cost me about $45-50 for rings, circlips, and wristpins....

[Prez]

Well, compression readings are the same as before. After it has time to warm up, it begins to smoke...after the oil gets to the top end, valve seals it must be.

[TheCafeKid]

Dont be intimidated bro! The hardest part of the valve seals is honestly getting the valve keepers back in. It will make you cuss Steve and I got MRiddles 81 1100E together today, after replacing a broken cam, and finding the culprit for the broken cam. Thinking that we're in the clear, we didnt replace the rings or seals. Well, mistake. Should have done it while we had it apart. Bike fired right up, sounds great. Smoked the whole neighbourhood out with oil passing the seals tho. So, back off the head came. This time we took the jugs off too and took a look at the rings, and rehoned the bores. Its really really not hard man. Take your time, and have the manuals handy Feel free to ask questions!

[Steve]

Whaddya mean, we were "smoking up the neighborhood"?


Yeah it was a bit disheartening to have to do it, but it only takes about 2 1/2 hours to go from this


to this.


Tomorrow (actually later today) we will have the fun of using my smaller version of a valve compressor tool to work on a 16-valve head to change the seals.
Another 4-5 hours and it should be running again.

.

[skidMarkNZ]

God damn ur engines pretty n clean.

Oooo lala.

[Prez]

That's exactly what it looked like Steve LOL.

[80GS750]

the best part about these old engines is how easy they are to work on....

i feel more confident working on my 30 year old GS than i do working on my new lawn mower.....

[tkent02]

Some related info here. http://www.thegsresources.com/_forum...d.php?t=125631

Basically, went through the carbs, after re-installing them I was trying to fine tune. Just as before the carb cleaning, #3 still seemed to be running rich (headpipe was cool enough to hold). So I went about leaning out that cylinder, eventually ran the fuel pilot in to a lightly seated position. Revved it up to 4k for a several seconds to burn out the unburnt fuel, suddenly it starts pouring oil smoke out the right side.

Fear is, that I leaned #3 out too much, thus overheating it quickly & scoring the cylinder or effectively "melting" the rings or valve seals there. Planning to do a compression check this evening, if I get home from my side job in time. Possibility #4 could be the culprit, since the compression was low there before, like it might have had a ring problem.

Headpipe cool enough to hold...
It Has nothing to do with mixture.
It hasn't been firing at all. Probably due to a fouled spark plug or a bad wire, maybe that cylinder is just thoroughly flooded.

So now that pipe is full of unburnt fuel, it's going to smoke when it does fire.
You didn't do any damage running it lean, you didn't run it hard enough or long enough to hurt anything. It just has oil, fuel, whatever all over the place in the cylinder and in the pipe, it smokes when it burns out.

Get it running on all cylinders and ride it. Hard.
It needs to be ridden. A lot.
With all cylinders firing. All the time.

Compression will come up, it will stop smoking.

[Macmatic]

Get it running on all cylinders and ride it. Hard.
It needs to be ridden. A lot.
With all cylinders firing. All the time.

Compression will come up, it will stop smoking.

I second this. A few weeks ago after a carb cleaning I had a cold pipe. Compression readings showed 140psi on 1,2&4 and 90psi on 3. The bike also started smoking up a storm and I was sure I was going to have to pull the engine apart.

After pulling the carbs, checking (and resetting...) the float height and checking the spark I got it running on all four again. It was SMOKEY but I let it warm up and after about three cycles of starting, getting up to temp and them cooling off to where I could hold the header pipes the smoke pretty much went away. I changed to 15w40 like I used to run and the smoke was gone...at least in the garage.

I should be able to put on some miles this weekend and see but the moral of the story is not to think you need to open the engine up just because it suddenly started smoking. Even with my low pressure reading which really made me think I had a problem it turns out that all she needed was to run. Hot compression is not 150psi across the board.

/\/\ac

[Prez]

Headpipe cool enough to hold...
It Has nothing to do with mixture.
It hasn't been firing at all. Probably due to a fouled spark plug or a bad wire, maybe that cylinder is just thoroughly flooded.

So now that pipe is full of unburnt fuel, it's going to smoke when it does fire.
You didn't do any damage running it lean, you didn't run it hard enough or long enough to hurt anything. It just has oil, fuel, whatever all over the place in the cylinder and in the pipe, it smokes when it burns out.

Get it running on all cylinders and ride it. Hard.
It needs to be ridden. A lot.
With all cylinders firing. All the time.

Compression will come up, it will stop smoking.

On the headpipe, was thinking it wasn't firing because it was flooding. It would stall or nearly stall if you pull either #3 or 4 plug wire, which led me to beleive it was firing.

Also, after re-checking the compression last night, I ran it for a bit...no smoke until after it ran for a several minutes (time for oil to get up top or #3 to fire), appeared to be oil smoke, wife said it smelled like burnt rubber (I can't smell).

Then again, if the pipe is full of fuel I can see it not burning it off until it gets up to temp.

[NATEO]

Whaddya mean, we were "smoking up the neighborhood"?



.

you havent smoked out the neighborhood until you have to burn Mystery Oil out of the heads!!! this lasted probably a half hour of continuous run time. spread out over several days.