Erratic Idle???

[frcfed4]

Alright this is a question from my buddy with his 400. He took the head off the motor to change the head gasket and put everything back on just how it came off. Except he said that there was kinda a timing thing in the head and the dude that helped him pushed one something and moved it. anyway back to the problem. When they started it up with the choke on it rev's real high and the head pipe turns red. I was told this is bc the motor is running lean. Also with the choke off it barely stays running if at all and backfires like a son of a *****. After the key is shut off it pops real loud. I myself took the plastic pipe that runs from the air filter to the carb off while it was sorta running to see if the choke plate moved and it doesnt. While the plastic pipe was off the motor shut off and it shot a small little flame out of the carb.

Notes: We went out riding the day before and it ran just fine.
He took it out right before they tore it apart and it ran fine.
No adjustments made to fuel at all and i believe it still has stock jets.


Any help is greatly appreciated

[Colby@C&DRacing]

You have two chioces your timing is off our you have an intake leak that is leaning your bike way out. I would go with the time issue first. Give me a call if you need any help:)

[400exrider707]

Yeah check the timing first and then worry about your jetting.

[murrays400ex]

ya i agree check your timing and make shure he tightened everything it could be that simple

[frcfed4]

called one of my buddies when i woke up and he said that it could be that the head gasket blew already b/c of it not being torqued down correctly...does that make any sense