400EX Won't Start

[MoparManiac117]

I think we're getting closer to the timing being the culprit. On the chance that maybe the battery wasn't making full spark, I hooked a jumper box up to it. No differene. Then I took the plug out, sprayed some starter fluid in the cylinder, put the plug back in and left the jumper box hooked up while I tried to start it. Still nothing. Didn't even make an attempt at starting. The starter just sounds like it's free spinning. I have an '07 400 I keep parked right behind his. Just for a comparison I fired mine up. The starter sounds like it's trying much harder to turn the engine over. I guess checking the timing is the next thing in the list

[Drifterboy3]

Given how it sounds I would be willing to be it is a snapped timing chain

[87TRX310R]

It could be the cam decompression, If it sounds like it wants to start when you keep pumping the throttle then that's your problem. I had that happen to my 400EX.

[MoparManiac117]

Given how it sounds I would be willing to be it is a snapped timing chain

If the chain was snapped, I would think the valves wouldn't move. They're moving in the head, so it could be just out of time. I'm curious about the valve clearance though. Once I dig my feeler gauges out, I'm going to check that before I pull the valve cover off.

[Drifterboy3]

Your correct they would not move. I didn't know you ever pulled the valve cover plugs

[MoparManiac117]

Your correct they would not move. I didn't know you ever pulled the valve cover plugs

I just pulled the lash inspection covers to make sure I was getting valve movement. Once I find my feeler gauges, I'll check the clearance and then pull the valve cover and check the timing. I think it's in the valve train.

[Drifterboy3]

We'll make sure you set the engine to TDC before you pull the valve cover. Otherwise you can strip bolts in the head.

[Stickman400]

I have the same problem with a friends 300ex that he brought me to fix. It's getting everything it needs, spark, air, fuel is getting in and out of the carb., valves are in spec, has good compression, new plug, fresh gas, wiring is good, kill switch isn't on. Damn thing still wont start for ****. Some how the carb is getting fuel into it and out of it, the valves are opening and closing yet fuel isn't getting into the cylinder. I took it to a friends to see if he can find out what's wrong with it. I ran out of ideas, other than ether, but that wouldn't help the main problem.