GS650L Smoking Badly - Help!

[Norseman]

Hello, Folks.
Been quite a while since posting, but I could really use some insight here. I have a 1981 GS650L with 25K miles. Lately the bike has increased in heavy white smoke, mostly from the left side exhaust. There is a relatively significant amount of black oily liquid dripping from the left exhaust can as well, but there's some in the right side as well - enough to leave drops/spills on the ground. However, it doesn't smoke when idling or at low RPM's. It really only smokes when driving above 30 miles per hour.

This smoking started by occuring sporadically, and would stop if bike was shut down and then re-started. But now it is consistent.

Bike starts up great and engine runs very smooth. Last year I did a compression test and compression was #1=135, #2=165, #3=160, #4=130. Valve clearances are all exactly nominal according to specs.

My question is whether you guys think it might be the piston rings or valves not seating good? I realize this could only be a “guestimate”, but I’m trying to determine if I can afford to fix this right now. I certainly would appreciate any feedback!

[focus frenzy]

check your oil level. likely you have crank case full of gas or have burned a hole in a piston.

[duaneage]

Doesn't look good, the oil might be too high or contaminated. An old trick is to put a teaspoon of trans fluid in the cylinder and retest the compression. If the numbers improve significantly the rings are shot.

[Dave8338]

I've heard of worse number (compression wise) and if you didn't do the test at WOT your numbers may be skewed a bit.
As for the oil blow-by and smoke...chek out the link below (#15), it would be my guess as to the culprit:

http://www.bikebandit.com/suzuki-motorcycle-gs650glx-1981-camshaft-valve/o/m6093sch271601

As long as the cylinders have not been washed as mentioned by Herb...you should be OK. If you holed a piston, you would hear it and would have a good miss to go along with it.

[SqDancerLynn1]

I would wash the motor and change the oil. Like said check it for fuel

[duaneage]

THe trans fluid test should provide clue, don't put too much in or it makes a mess. What is the amount of oil consumption? If you are fogging the block it should be thirsty.

[Norseman]

Thanks for all the insight, guys. I can't imagine a piston has burned through - compression numbers ain't that bad and the engine sounds great. When I did the compression test, I did put a little oil in each cylinder and ran test on WOT.

It seems to me the suggestion Dave8338 made relative to valve guides/seals makes a lot of sense. Oil consumption is relatively light, but I don't have any exact number on that yet.

My Harbour Freight compression tester disintegrated (no surprise there!), so I can't do one until I can replace it. However, if I understand correctly, if I do a valve job I might as well tear down the entire top end and install new rings if needed anyway because I will likely have to replace all gaskets to avoid future leaks from re-tightening on old gaskets?

[ryonker]

I had a friend with a similar problem. He wasn't turning off his petcock and gas leaked into the crankcase.

Like was said, drain your oil and check for gas. This is an easy first move.

SquaredancerLynn1, how do you wash the motor?

Good luck!

Rick

[skidMarkNZ]

Sounds like my old motor, i couldnt be bothered with it so just bought another identical bike for parts...

Was burning a litre of oil every 200km's LOL

err for you yanks.... 1/4 of a gallon???? errrr 120 miles...

[tkent02]

One of my 1000s did that, black sh:t dripping all over the pipe, running all down the cylinder, smoking like the Marlboro man.
Turns out one of the pilot jets fell out, and the float valve was stuck open, resulting in that one cylinder being way to rich to run at all. Sucked a tank of gas down in about 100 miles.
Fixed these two little things, now she's a fvcking rocket again.
By the way, anybody in the Dallas, Texas area want a fvcking rocket, cheap?

[nisom512]

One of my 1000s did that, black sh:t dripping all over the pipe, running all down the cylinder, smoking like the Marlboro man.
Turns out one of the pilot jets fell out, and the float valve was stuck open, resulting in that one cylinder being way to rich to run at all. Sucked a tank of gas down in about 100 miles.
Fixed these two little things, now she's a fvcking rocket again.
By the way, anybody in the Dallas, Texas area want a fvcking rocket, cheap?

HAHA I wish I could buy it but im not down there. but what are you asking any who?

you may want to take a look at this thread might have some good info for ya.http://www.thegsresources.com/_forum...d.php?t=139809