Smoking Problem

[gaguy87]

I have a 2004 honda 400ex. It was making a noise a high rpms and blowing white smoke when you first cranked it up so i agjusted the valves and it took care of it. Now it is blowing black smoke when i rev it up. What could be the problem. My friends dad says the timing may be off. But I think it seems like it may be the tensioner and it did skip timing. What yall think?

[VTredneckgames]

Rule of thumb about smoke

White = Water

Blue = Oil

Black = Fuel

How long have you had it? How long has it been doing it? Did you set the valves to spec?

[gaguy87]

I have had the atv for about 6 months. Once I adjusted the valves it did it about 2 minutes after I warmed it up.

[timmy400exfast]

id check first jetting then id tear into the motor look at the valves and seals then the rings check out the cahain and guides also if you are going to do this

[gaguy87]

My atv is stock. I should not have to jet it.

[VTredneckgames]

I'll tell you exactly what I would do. Pull the head and the jug, take it to a machine shop for work. New seals, valve grind, etc. HAve the jug checked for egg shaped. If jug checks out good, re-ring the piston. While you have it apart, drop in a CRF450 timing chain. Bolt it all back up and drive it another 5 years. ~ $120