sound like valve issues? please help me!

[400thacker]

well i rebuilt my quad and have rode it for about 4 hours or so and i was about 1 mile from my house and it lost power and made a nasty metal on metal sound in my engine. i stopped at by friends house who was riding with me and let it cool off real good and it started right back up and ran fine for about 5 minutes. i started riding back home 1/2 mile away and it done the same thing again.
i know you are supposed to re adjust your valves after a few hours on a fresh rebuild but is that whats really causing my problem? it ran great the whole ride.
I thought that maybe the oil pump went bad but i have a bad gasket on my timing chain tentsioner and it is still leaking pretty good so i think it's getting oil. i just don't understand how it can make that sound and lose poswer and die then cool off ans start back up run for 5 minutes and do it again.

ANY IDEAS ARE GREATLY APPRECIATED!
thanks a million,
Dan

[250x_kyle]

when you hear a nasty metal on metal sound dont fire it up and ride it home tow it. could be valve clearnces off could have jumped time and bent a valve

[250x_kyle]

could be a number of things

[400thacker]

well i adjusted my valve clearance and tried to start it but i am not getting fire. it was not puting out enough to make the plug spark.


anyone else ever had this happen? I mean there are only so many things that will make one lose power and die, then cool off and start back up and run great with no noise for 5-10 minutes.

correct me if i am wrong. if i bent a valve just enough to stick sometimes then that will make it lose power when it does stick and cause the bad noise when the piston comes up and hits it, right? does it make sense that thats the case and when i let it cool down and the metal de expanded it lets the valve move freely causing no noise and no power loss?

keep the ideas coming guys.

[400thacker]

bump

[400exrider_88]

got compression in the motor? every motor needs a certain amount of compression to fire. this problem sounds like what happened to a friend of mine. he was doing some burnouts and reving the **** out of the motor, it had no rev limiter. then it ran like crap, had no power.