smoking

[81 clark racing]

when in neutral and i rev it up, on the dec acceleration it puffs smoke. the smoke dosent really have a color its a very light puff of smoke. could this my jetting, valve seals. or rings? also its a 400ex thanxs

[underpowered]

i would say probably just your valve seals, no big deal. if only a few bucks to replace for the parts.

[81 clark racing]

should i wait and see if it gets worse or is that a bad idea

[pigpin]

i would have to go with rings, or possible extremly rich or lean, although thats something that wouldnt just change on its own. im a honda certified tech and the true tale sign of valves seals is smoking when you first crank it up then it clears up, this happens becouse the seals harden and allow oil to seap by down into the combustion while the engine is off, and then when you first run it all that oil is buring out of the engine, but a little smoke never hurt anybody, just make sure its always full of oil and you'll be fine. unless it gets to point you cant bare to stand it and its embarrising to ride.

hope this helps!