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95300exrida
07-18-2005, 10:11 PM
hey i just rebuilt my 300ex with a 76mm piston and it ran fine and errything but i was ridin down the road at about half throttle and it just died im thinkin i blew it up but i just wanna make sure could it be anything else?i mean it has absolutely zero compression now
07-18-2005, 10:13 PM
yeah i know you probably checked this 10x already but your gas is on, right?
XCredrider
07-18-2005, 10:50 PM
how do you know it has no comp? did you do a comp test? if you dont have a comp tester just take out the plug and put your finger over the plug hole. when you turn it over it should push your finger off to let ou tthe gases. If not then you could have possibly just burnt up the rings or something small like that. any funny noises or any signs of anything before it stoped? it should have smoked if you burnt the rings or anything like that. :confused:
95300exrida
07-19-2005, 10:46 AM
i know it has no compression because when i crank it over the starter goes really fast and the piston goes up and down without resistance and it didnt smoke or anything it just died
07-19-2005, 11:05 AM
take your cam cover off and make sure there isnt anything wrong with the cam/timing chain
95300exrida
07-19-2005, 11:25 AM
a stuck valve could cause all these problems right?if i have one how would i get it unstuck?
big_saxy
07-19-2005, 11:37 AM
The same thing happened with my dad's old 86 forman 350. I had it topped out at wide open throttle and it just died. It cranked over really fast but would not start. Ended up being the camshaft and both exhaust valves were toast. Sounds like you have the same probem. sorry dude!
XCredrider
07-19-2005, 03:01 PM
it doesnt sound like the piston.. you would have either heard something or it would have smoked. My bro had an older honda dirtbike that did the same thing. The timing had jumped, if i remember right. Once we set the timing back it went back to running. I have my money on a problem in the head though.
95300exrida
07-19-2005, 08:20 PM
hey it was a broken cam chain
XCredrider
07-20-2005, 10:36 PM
i win. haha. that must have been what happend to my bros bike. double check everything the next time to make sure its in good cond and put in right. Anything else break?
95300exrida
07-22-2005, 11:32 AM
nothin else is broken as far as i can see