QuestionI purchased a 1992 Yamaha TW200 approximately 3 months ago with approximately 2000 miles on it. Recently I have noticed white smoke coming from the exhaust (it does not appear to be blue and it doesn't have a real noticeable smell of burning oil). The bike generally only smokes during the first ride after it sits for a week or two. I've pulled the plug to see if it is fouled up. The plug appears fine with only normal carbon build up (and it’s dry as well). I wanted to get a mechanics thoughts before I tear apart the head looking for problems. My initial thoughts were that the valve seals may be hardened or potentially it has some bad rings. The bike starts and runs great, and does not appear to be using oil (I have not added any oil and the oil level remains where it should). If you think that this could be a valve seal or ring issue, do you suggest using any products to help seal things up? Your thoughts are much appreciated.
AnswerJoe,
-the bike is hardly broke in at 2000 miles.
-White smoke is usually just
water vapor burning out of the exhaust
pipe or possibly the oil or gas if it
has not been changed recently.
-Valve seals can get hard but the smoke
would likely be bluish and increase when
letting off the throttle on a long down hill.
They cause very little if any engine damage.
-If the oil ring was stuck it would also
blow bluish smoke and would require
a top end repair.
-If it runs good and the spark plug is not
fouling, I can't see it being worth
tearing down a low mileage engine.
-Have you checked the air filter for
moisture or being oily?
-I would change the oil and use some 10W40 motorcycle oil
with no additives.
-worst case it may need new rings,
head gasket, valve seals and the cylinder honed.
Maybe the valves ground or lapped.
Should be lots of blue smoke though.
