Frustration!!!!!!!!!!!!!!!!!!!!!!

[Throttle_Junky]

So I overheated my 400 EX on a big trip awhile ago. so I decided to do a top end job and quit buring oil like a hillbilly. So I do my top end job, new piston, wrist pin, rings and gaskets. and then bolt my engine back together. Everything that I know of is in order but it will not run. Gas and air are present and being exchanged. oils full, spark is sparky, and all I get is pop....pop.....pop, it will fire here and there, but not RUN. tryed pull starting and nobody home. (400ex's have a phantom spark, right? i'm sure they do) and the book does not tell you how to adjust timeing. Since everything else is in order I have concluded that the timeing is out somehow. can anyone please tell me how to adjust timeing???? Please help if you can.

[yzbluebeast]

Ignition timing likely won't help if your cam timing is off.
I would look at the cam timing again.

[Quad Dude]

welll it very well could be ur timing but if it acts like it wants to start my moneys on that u didnt put ur decompression spring back in and the pin is stilll in there. because then it will come close to starting but it never will.

but if im wrong this is how to set ur timing. set it on TDC (top dead center) and your cam has two marking on it and they have to be set parllel to ur cyclinder head then you put on ur timing chain. oh and it has to be on the compression stroke and to know what stroke its on put ur finger over the spark plug hole and when air starts pushing past ur on the compression stroke then set ur TDC and to that other stuff.

GOOD LUCK
josh

[f1502nv]

i had the same prob... the timming was wrong...i was always adjusting 180 out its tricky cause i thought i was on the compression stroke but i wasnt. once you get it right you have to pass tdc by 1/2 turn then go back and adjust the valves that will realease the compression.if you dont your exhaust valve on the right front will be loose and clank

[wilkin250r]

There is no way to adjust the ignition timing. If you have the flywheel key in, and you're using a 400EX CDI, then your timing is correct, it CAN't be off. That would be like saying the crankshaft timing is off. The timing is taken directly off the crankshaft via the flywheel.

Obviously, the cam timing CAN be off.

By phantom spark, you mean a spark on the exhaust stroke? I'm pretty sure they do.

[Throttle_Junky]

yes, phantom spark is a spark on the exhaust stroke. and it must be that my cam timeing is out a tooth or two on the chain, because (as I suspected) the ignition timeing is on the crank.

and QUAD DUDE said somthing about a decompressore spring?...? there is a decompression cam that we looked at and is funtioning properly. soo...

thank you all for your sugestions , althought the machine is not yet running. and I won't have time to work on it tommorw, It will be looked at on the 23.

anybody with new ideas please fire them out.....

[DieselBoy]

Throttle Jockey, did you ever sort this problem out I am having the same problem Its popping but it wont GO...