Backfiring Question

[GEARSMOKER]

just did a new wieseco piston, and hot cam stage one cam in my friends 2000 ex. adjusted the valves to spec, and now when you let off the throttle after high revs, it backfires pretty decently. any ideas? thanks guys:D

[skyhighatv]

was the motor stock before rebuild? did you re jet for mods? open air box?

[RiderTRX400ex]

go bigger on the pilot jet, adjust mixture screw

[GEARSMOKER]

motor was stock, 155 main jet ,with a closed air box. new piston is stock size.

[nowukno]

Originally posted by RiderTRX400ex
go bigger on the pilot jet, adjust mixture screw


Its usually one of those two.

[Speedy81304]

two things. a backfire is when you flame out the carb. an afterfire is when you flame out the exhaust.

if you back fire or after fire its cam timing. neather are a good sign.

[04'400ex'er]

You should be running around a 45 pilot with those mods.

I was going 5th gear on the road today n let off a bit n it backfired but it never backfires what was with that? just cuz i let off?