I recently purchased a 2002 honda 400ex and only when i rev it up will it shoot out a white puff of smoke??? It runs perfect and just had the valves adjusted what else could it be>> But it only happens when i rev it up not when idling??

 

Could be a few things,
Does the smoke smell like oil or coolant?

 

LOL [img]i/expressions/face-icon-small-happy.gif[/img]if it smells like coolant you have major problems[img]i/expressions/face-icon-small-happy.gif[/img]

 

it kinda does smell like nasty oil and i have noticed when i just changed the oil i have lost a little so??

 

my guess wuold be rings

 

I just did a 2000 400ex , I had it bored 40 over but I think it burned oil because of bad valve seals,you could save some $ by just trying to replace them ( The 400ex's are noted for worn seals )

 

<div class="FTQUOTE"><begin quote>LOL if it smells like coolant you have major problems </end quote></div>
Ha ha ha ha, guess I should pay more attention on what engine he was talking about!!! LOL
In this case it's going to be rings or guide seals like these guys said.

 

yea that makes sense cuz the guy i bought it from just redone the motor so it it def has to be a screw up from him

 

Yup, almost for sure it's a coolant leak! haha, that's pretty funny. There's no coolant in a 400ex Doctor... :-)

 

It could also be that the rings were not installed properly. The gaps on the rings (compression and oil seal) should be 180 degrees apart. Easiest thing to do is to put the gaps of the rings on either side above the wrist pin.