Head gasket troubles, I THINK...help

[400MXer]

Wed, i went to a track and rode at a practice. I rode 4 15min practice sessions and not a problem with my quad, on the fifth one, i noticed that my quad would pop when i let of the throttle. like it was running to lean. and it wouldn't idle by itself. and it was REALLY hot. is this the head gasket. i checked hoses, jets, carb. do you guys have any suggestions.


what happened when you guys blew your head gasket's??

not sure what your problem si but i ahve blown enough head gaskets to know that thats not your problem...when you blow a head gasket you will hear exhaust coming out of the side of your head when you get on the throttle hard..and you will see oil,exhaust come out between your cylinder and head

[KY Woods Rider]

Like Nacsracer said, if you blew a head gasket you should be able to see a bit of oil coming out from somewhere around the head gasket. It might not be a large amount if it just recently blew, but there should be an oily/greasy spot somewhere around the head gasket.

If it was a head gasket, air leak, or a fuel or vent hose clogged, you should have noticed performance problems at different amounts of throttle, not just when you let off the throttle or let it idle. Therefore, based solely on your description, it sounds like the pilot jet might be clogged or partially obstructed. You said that you checked the carb and jets, but did you pull the float bowl and look inside the pilot jet to be sure that it didn't have a piece of trash caught in it?

[400MXer]

i just pulled my main out. i'll take the pilot and needle out tomorrow and check them! I think there is air getting in somewhere. it's running really lean, and super hot. i checked the boots and things but can't figure it out