Help!!GS 750 white smoke problem

[Guest]

Hey all,
let me start off by saying that I am new to working on bikes but work on cars alot and i just picked up a 1981 GS 750 from a guy i work with.

the bike had been sitting for 5 years and wouldnt start so once i got it home I took off the carbs and cleaned them really well, cleaned the gas tank and put a fuel filter inline. after putting them back on it start up right away but was blowing white smoke from the right side of the bike.

any and all advice would be great because I dont want to do something to mess the bike up since im just learning how they are compared to cars.

[chuck hahn]

Bad valve stem seals is what I would say. They tend to let oil bypass then its burnt inn the cylinders at start ups after setting a day or so. Basically the same process as with a car. remove the head, depress the springs and remove the valves. remove the old seals and put new ones on. Get a base gasket, new head gasket, and a valve cover gasket as well. One of these will be the manual...16 valve engine.

http://www.mtsac.edu/~cliff/storage/gs/GS750E-ES_Shop_Manual_1983.pdf

http://www.mtsac.edu/~cliff/storage/gs/GS750_16valve.pdf

[chuck hahn]

Rings are cheap also..and seeing youre gonna relief the base gaskets set when you remove the head..which is why i said replace that too...may as well do the full on upper end and be done with it for the next 25 years or so

Usually the seepage will burn off in a few minutes as the cylinders come to a good hot temp. But if it doesnt and the smoke persist at a constant level then the suspect would be bad oil rings. So yeah, just do the full top end and be done with any and all possibilites.

[londonboards]

Before you do all that make sure to do a carb synch. I had that smoke and spitting fire and all sorts on one cylinder. Synching fixed it good.

This was causing the white smoke (not blue oily smoke):

This fixed it:

Good luck.

[azr]

Before you do all that make sure to do a carb synch. I had that smoke and spitting fire and all sorts on one cylinder. Synching fixed it good.

This was causing the white smoke (not blue oily smoke):

This fixed it:

Good luck.

Great post, can't imagine how many people these 2 video's will help, well done!!

[azr]

To start with, is the bike firing on all 4 cyclinders? (are the pipes hot on all 4 headers)

[JTGS850GL]

Also, if the bike has sat for a long period of time, sometimes oil and water condensation can build up in the pipes. My GS1000 took several runs before everything was cleared out.

Do as azr suggested and verify that all 4 cylinders are firing.

[chuck hahn]

BILLOWING WHITE SMOKE doesnt sound like water vapor that disipates extremely quickly once it leaves the pipes. I think the guy knows the difference and what he is seeing. And yes hes saying "white' and youre saying "blue"..nothing more than descriptive semantics here.

[azr]

Chuck.....you ok???? ohhhh, I get it.....it's because JTGS850GL is actually ERIC BANG!!!

[chuck hahn]

Yes....wish the exact words the guy wrote were read thjough. Theres a very DISTINCT differance between oil and condensation smoke.

[tkent02]

Blue looks like white, white looks like blue, it's all about the lighting. The real question is what does this smoke smell like?

[chuck hahn]

My TX 750 spent the oil rings and in a matter of two minutes you couldnt see across the gargae and it lingered in the air for a LONG LONG time....which condensation wont hang aropund but a few seconds and be gone in the wind. Myabe the OP should clarify better what hes seeing???

[JTGS850GL]

BILLOWING WHITE SMOKE doesnt sound like water vapor that disipates extremely quickly once it leaves the pipes. I think the guy knows the difference and what he is seeing. And yes hes saying "white' and youre saying "blue"..nothing more than descriptive semantics here.

Chuck.....you ok???? ohhhh, I get it.....it's because JTGS850GL is actually ERIC BANG!!!

Chuck: The OP never said that it was billowing white smoke. He said it was blowing white smoke. May be semantics but when I hear blowing it doesn't give me the same visual as billowing. Why so angry at me again? I've had a few times where enough old oil and gas has accumulated in the exhaust pipe over years of sitting that it smoked for a while. Old gas accumulated in the pipe from a bad carb and later turned to tar. Just figured it would make more sense to give it some time then to jump right in and start to pull top end.

azr: You have got to be kidding me. I thought this was long settled.

[azr]

Yes...I was kidding.

[BigD_83]

azr: You have got to be kidding me. I thought this was long settled.

Nah,

we're going to force you to do the cross-country trek to the PNW rally next year to prove otherwise, AND you'll have to do it on a ride smaller than my 650G so I don't have the smallest horse in the stable, again