My 84' tt600 smokes terribly on start when cold-could it be valve stem seals or some other problem?

your bike is gone ,dude!

Good news
Your bike is not gone
I had same problem with 3aj Tenere
If the smoke clears and you have no sign of smoke with throttle closed while rolling in gear ie, stopping useing engine compresion
Its time for a rebore but while you are at it get the valves seated and seals replaced

Does it smoke only on start up?
If yes Probably worn guides:

does it smoke badly on acceleration?
then probably worn Rings/Bore

Does it drink lots of oil. and smoke all the time? head gasket rings and guides

My guse is worn guides as the oil is sweeping past the valve stems into the combustion chamber when it is hot and the bike is stopped. It pools in the cylinder and uou get lots of smoke on start up. Is it foualing the plug also?

Charlie

Yo Guys-Thanks for the reply.

Worstcase scenario would be the valve guides\stem seals but I have discovered that it could possibly be the choke of the carburetter somehow allowing too much fuel in on start up therfore burning rich and very black. The spark plug has also not burnt black as it would I guess with oil.
A second question I have is: what exactly is the pilot screw set on the carburetter and how many turns out should it be set to? I thought that it adjusts the ammount of air into the carb but am not sure. In the manual it says the screw is pre-set in a blind housing but this one aint in a blind housing and can be taken out completely. I'm not refering to the idle thumb screw.

Wait !!
We forgot the first question to be answered : what colour smoke are we talking about?
Black = fuel. Blue = oil. White = coolant.


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Fred, XTZ660, Holland.

Shot Fred.

Black it is. Pilot srew for fuel it is too. No more smoke-must have been running to rich too rich.