400ex rebuild cant get running

[monster400ex]

ive built a 416 kit with stage 2 cam no problem started up first try,
now ive built my buddys 400 with a stock bore 11 to 1 comp wisco piston mild port and polish/ port match new valve seals
put it together try to start it it cranks but it would fire every couple of strokes but not run. so i tried switching the cam out180 degrees which seemed better an out fie every stroke but not idle. tried adjustng the carb to no avail need help asap thanks

[AtvKid4Eva]

make sure your valves are adjusted correctly and recheck the timing. i built one that would do the same thing turned out the valves were way tight and it wouldnt start. timing will do the same thing if it is off a tooth or two.

[monster400ex]

k thanks im goin to check it out

[F-16Guy]

Check all of the grounds and connections that were disturbed, look at the plug wire and boot, and throw a new plug in it. The cam can't really be 180 degrees out, so that shouldn't be an issue.

[killer400ex]

the cam builders give you a bolt on ready cam, all you have to do is adjust the valves due to the bigger lobes, advancing the cam is not a smart ideah imo on something like this

[EXKid416]

Didnt say that you installed a cam. I've seen a couple times where people left out the little spring and plunger that sit in the head and push on the decompressor cam. That will cause it to fire once a revolution but not start up.

[Dobber]

Originally posted by EXKid416
Didnt say that you installed a cam. I've seen a couple times where people left out the little spring and plunger that sit in the head and push on the decompressor cam. That will cause it to fire once a revolution but not start up. decompressor is most likley your problem take out the plug on the stator cover and get a 17mm socket i believe and jurk the motor back and forth a few times sometimes this will release it if its stuck but if you forgot the spring and pin thats definatly your deal