04 Runs for 30 seconds and dies??

[blacknblue#2]

Ok my buddy just got done building an engine for his 04. He went with a hot rods stroker crank, athena 480 kit, stage 3 hot cam. he put it back together and started it. It ran for about 30 seconds and died and wouldnt start back up. Now if you let it set it will start back up and do the exact same thing. what could it be. We tried EVERYTHING electrical off a running quad and it didnt help any.

[440challenger]

is it just running off the gas thats in the bowl?

[ss440ex]

Originally posted by 440challenger
is it just running off the gas thats in the bowl?


Check for kinked fuel supply lines...

Fuel tank cap vent.....

[drgnerth]

It has no spark after it dies, so it's not the fuel. But you let it set a few minutes it will strt back and yhen dien 20-30 seconds later. We took stator , harness , cdi every electrical part off of another 450r and it does the same thing. The keyway is still on the crank. The only thing that hasn't been changed is the flywheel, but i don't see how that could cause this.

[h400exrydr]

the same thing happened to me on my 04. it ended up being the throttle position sensor or TPS. it is on the carburator, i would try that.

[drgnerth]

If you unhook thr tps it should be fine right?

[h400exrydr]

not sure, could try it. but dont take it loose unless you know what you are doing. the TPS has to be set perfect. i have never brought my quad in to a dealer, but for that i did. it was the first thing that has stumped me that i couldnt fix.

[osu_josh]

does it die slowly or is it like you turned off the key?