Smoking on start up

[HolisticBlackGS]

I have an 83 gs650gl and when i start it up one of the right 2 cylinders (sitting on the bike) seems to be burning old because there is a white smoke comming out of the exhaust. After 5 to 10 mins of running and warming up it goes away Oil change? Anyone know any possible causes to this? Also i just bought the bike and i dont know the work history of the bike, so what can i do to make it run better? Oil change? trans fliud change? carb cleaner? Carb rebuilds? new air filter/cleaner? Also untill the bike warms up the idle is real rough and in the low rpms. I know there is a small exhaust leak which i am getting fixed. Thanks for any help anyone gives me.

[chef1366]

Classic valve stem seal issue.

[HolisticBlackGS]

Classic valve stem seal issue.

any fix for this?

[psyguy]

lots of work

valve stem seals are inexpensive
however, the head has to come off, all the valves out... new head gasket...

[Colin Green]

valve stem seals are inexpensive
however, the head has to come off, all the valves out... new head gasket...

I've been wondering if that was/is the case with mine as after about 20 or 40 seconds at fast idle she smokes a lot. Figured it might have been leaking around the stems but wasn't sure

[SPARKSS]

If it's burning oil, the smoke will smell heavily of raw burnt oil....stick your head right in there and find out Usually the color would be more bluish but different people see it differently. Does it start and run normally other than the smoke? If it doesn't....that is it seems to start on 2 cylinders and run roughly then abruptly start to fire and come up (coincident with the smoke) then it may be raw fuel vapor that you're largely seeing......this will also smell uniquely of gasoline. This latter symptom can point to ignition or even compression probs OR fuel leaking into the cylinder while shut down (which causes a temp compression prob AND raw fuel to be pushed into the exhaust AND a misfire which may clear up if the plug doesn't foul in the process).

My .02 worth

[rombi]

I just noticed this morining the same thing with my 82 650e.
it is the left muffler on mine though. It runs great but on start up with the choke on it smokes pretty good. Choke off no smoke and runs very strong. I am not too worried about it yet but I would like some opinions as well.

[catbed]

condensation boiling?

[Outlander]

On my 80' GS550E, when I first fired her up after a long nap, (8 years worth) she smoked like crazy. Huge white clouds. Didn't smell all that great either. After about a week, it all cleared up. I don't know what caused it, but it seemed to rectify itself. I figured that because it sat so long, that everything needed to reseal and re lubricate. Now, she is fine, and I am totally thrilled with her.

[robertbarr]

any fix for this?

There is a really inexpensive course of action:

Just ignore it, and ride the bike as if you didn't notice any smoke at start-up.

Maybe once in a great while it'll cost you a pair of new plugs, but so what? They don't last forever anyway.

As for your other list of questions, there's always BWringer's litany: (swap '650' for '850')

*****************************
From Mr. bwringer:

Every GS850 has (or had) a set of well-known issues that MUST be addressed before you have a solid baseline for further troubleshooting.

It's a vintage bike, and it's quite common (as in, every single GS850 I have had contact with) that there are multiple problems that have crept up and slowly gotten worse over the years.

It's not like a newer vehicle, where there's generally one problem at a time.


These common issues are:

Intake O-rings (install NEW OEM or Viton only - common nitrile o-rings will quickly deteriorate from heat)

Intake Boots (install NEW -- these cannot be repaired)

Valve clearances (more important than most people think)

Carb/airbox boots

Airbox sealing

Air filter sealing

Petcock (install a NEW one)

On '79 models, install new points or Dyna electronic ignition (or at least verify that the old points are working correctly)

On all models, it's fairly common to have problems with the spark plug caps. These are $3 or $4 each, and often worth replacing if you're keeping the stock coils/wires.

Stock exhaust with NO leaks or holes -- good seals at the head and at the junctions underneath.


None of these things can be neglected, worked around, or half-assed in any way. Once they are squared away, you most likely have a bike that runs like a dream -- these issues account for a very large portion of running problems.

If not, then you can pursue more exotic problems. For example, I have found incorrect float heights a couple of times due to a common misunderstanding in how these are best measured. But you can't uncover other problems without making sure the intake/exhaust paths are leak-free, the valves are adjusted correctly, and you're getting good spark.

[Roostabunny]

I had a very similar problem (white smoke during warm-up from the left-hand pipe) that was also fouling my number one plug with black stuff that I couldn't identify between oil or carbon. Too shiney for carbon, too dry for oil. Anyway, it wasn't clear to this newb mechanic (or my pro mechanic friend) and pictures of plugs on the forum weren't helpful in my case.

So, given a choice between a carb rebuild and a head rebuild (for the valve seals) I chose the carb rebuild cause I had the parts already. I got a little lucky and that fixed the problem - I think it was a clogged hole under my #1 mixture screw.

So, compare all your plugs and let us know what you see.