Hey guys,
I just bought my 1999 cbr f4 about 2 weeks ago. It seems after a cold night / pretty much usually when I do a cold start the bike has a lot of white smoke coming from the exhaust. Its very white, no blueish color at all and it only happens on cold starts. The bike starts up with ease (with choke) and other than this she seems to run pretty well. There is also a pretty good odor of gas, maybe im running rich ? The po had a stage 2 jet kit installed so maybe he didnt measure fuel air ratio correctly ? Ill attach a pic, thanks in advance !

 

And yes, i used the search and saw the thread titled the same.... but his problem seemed a little different than mine. 1) with mine it never happens when the bike is warmed up 2) its a constant, evertime i do a cold start it happens 3) it does not keep doing it once i start moving. Could this just be moisture buildup ? Im in southern OR these days and Im hoping that its just the really high humidity here causing moisture to build up in the exhaust over night. Am i over analyzing this ? -___-

 

How cold? Have you ever lived up north before?

It is possible you are just seeing the normal condensation that happens with all combustion engines on cold days. Any time it is under roughly 45F any engine exhaust will emit condensation vapor. It is white but is water vapor rather than smoke.

 

Its definately been below 45 degrees at night, and its been either raining or foggy on and off the past few weeks. Thats what I figured but then I saw something regarding valve seals and I got paranoid ! Thanks 4 the reply and I hope thats the case.

 

From what I see there, nothing apart from exhuats vapour... and if the bike runs nicely, then nothing to get worried about. Worry when it's blue or black lol

 

Yea i would keep an eye on it but if it goes away on warm days its a pretty clear sign that its just normal condensation.