400ex timing?

[400exrider707]

Ok recently I took all of my aftermarket stuff off of my EX and Im putting it back to stock. Ran perfect before all of this. I put the stock exhaust back on and the stock cam back in. Now when I tried to start it it just turns over and pops but wont actually run. I figured the timing was off. Well it was 180 degrees out. I fixed the timing and try again and its doing the same exact thing. I know its sparking for sure. The plug appeared wet when I took it out so Im assuming its getting gas. The timing is on or at least I believe it to be. When you run a timing light to check the timing, which mark on the flywheel should it be lighting on? Also any other ideas. Tomorrow Im going to try and pour gas directly into the cylinder, and also try towing it to pop-start it. Other than that Im runnin out of ideas. Mainly need to know about the timing light which mark its supposed to light up. Thanks.

[400exrider707]

No one knows?

[JOEX]

At idle it should be on the F mark.

[400exrider707]

Ok thats where it was. Im thinking that I might have a bent valve possibly now from it trying to start 180 degrees off before. Im going to see if I have the right compression tester to test it tomorrow. Thanks joe.

[03pissedoff426]

wow, 180 degrees off, ouch. i hope the valves arent bent. if so i have a used set for sale. about 10hrs on them. i replaced them with oversized black diamond valves. let me know if you want them.

[400exrider707]

Originally posted by 03pissedoff426
wow, 180 degrees off, ouch. i hope the valves arent bent. if so i have a used set for sale. about 10hrs on them. i replaced them with oversized black diamond valves. let me know if you want them.

180 just means that the cam was put in upside down more or less. The valves wouldn't bend from that now that I think of it, because at 180 degress off, its just opening the exhaust instead of intake and vice versa. Shouldn't be any bent valves.

[03pissedoff426]

well incase you didn't know, as a future reference the lines on the cam gear should be level with head. and the bolts holes should be up and down. and when on TDC on the flywheel the lobes should always be facing down. just for anyone else who reads this and might need that info.

[400exrider707]

Originally posted by 03pissedoff426
well incase you didn't know, as a future reference the lines on the cam gear should be level with head. and the bolts holes should be up and down. and when on TDC on the flywheel the lobes should always be facing down. just for anyone else who reads this and might need that info.

Yeah I understand that but obviously you dont understand that at 180 degrees off the lines still line up with the head. Im having trouble finding which TDC is the compression stroke. I dont know wether or not the cam sprocket is correctly lined up with the valve timing. Usually there is three marks on the cam sprocket. The two side ones to line up with the head and a third that goes vertical to show when it is on compression stroke. My problem is that I dont know if the cam sprocket was put back on correctly. It could be upside down. The machine seems to have the same symptoms no matter which way the cam is in the machine. Im getting really confused now. Its getting gas and spark. I still have not been able to check compression though so that is pretty much my last option. I dont really see how I could have bent a valve though. It ran perfect before I put it back to stock. Anyone else have any other ideas?