I have a question about the engine running rich.

[400exRider12345]

Hi,
I am buying a 99 400ex. The owner told me that it runs rich. I ahve absolutely no clue how to play with the jets or even what running rich will do. Is this a bad sign? Is it an easy fix? Also if it is, would i be able to do this myself? What are the side effects of having ths run rich. Any in he long term? Is this gonna be bad for the quad? Should I stay away from this quad? I need all the info i could get.
Thanks,
Damian

[mikeboone]

Running rich means the motor is getting more fuel than oxygen. It actually comes lean from the factory for emission control. (more air than fuel) Changing the main jet is very easliy done in 5 minutes. Each jet has a # stamped on it. The stock jet is a #148 The higher the #; the more fuel can flow through it. It wont hurt the bike in the long run; but it will hamper performance if it is rich. I would not consider this as the only reason to buy or not buy the bike. How does it look and run? These are factors you need to look at when neg. a price if you decide to buy. What other aftermarket items have been added? Does it have a new exhaust? The stock pipe is dull black and has a removable endcap. Check on kbb.com for a good idea of its value or post a topic here. MB:D

[400exRider12345]

hey,
thanks for the info i really appreciate. it is hondaboy's quad. he has an ad posted in the classifieds section.