White smoke from exhaust on yz 250 - YZ 250 Yamaha Motorcycles

SOURCE: exhaust pipe comes out white smoke when start bike on side stand

Continuous or just for the 5-10 seconds.
If continuous you may have oil seeping past your pistons oil rings or valve guides oil seals.
Check your spark plug see if they are fouled badly (covered heavily and oily) or just covered by oil and sooth lightly.
If 5-10 sec it is normal as the engine is heating up there are normally a little oil seeping past the seals.

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SOURCE: white smoke on exhaust

White smoke is usualy water (blown head gasket)

SOURCE: the yz 250 1986 has the same engine as the tri z

im not that good with carborators so any help will be great .

Simon Ryan

• 2 Answers
• Posted on Nov 17, 2013

SOURCE: RD 250 - I am

Hi people ' if White smoke is continuously coming out of pipes there are many facts and causes first if you are losing power also it may be piston rings worn (2) if White smoke is jetting out when reving engine, depending on the fact that we are talking about 2 stroke engines then check 2 stroke oil mix is measured out before put in fuel (3) check and test 2stroke oil pump for adjustments and reset (4) most important crank case seals give off symptoms of above .. Poor idleling loss of power & compression . Check these areas out . Hope this helps simon R. :)