need help quick!!!

[spud400ex]

when i ride the ex for about a half-hour it starts lossing power on the topend. it fells like theres nothing past 6000rpm and is popping really bad. i did a search and didnt find anything. i have to get it fixed in the next two weeks for a dune trip.

[mojoe2878]

sounds like its over heating. make sure you dont have a exhaust leak close to the engine that would be letting it suck air in, and check around the intake too. a bad air cut off valve on the carb can cause it to pop and back fire when you let off the throttle. pull the plug and let us know what it looks like. also you may want to pull the bowl off the carb and make sure there no dirt or trash clogging up your jets. another thing is to make sure you are gettin enough oil (clean oil screens in tank and engine, and check the pump) . ive seen them overheatin and runnin bad all from oil starvation because the owners never cleaned the oil pump strainer in the engine and they become stopped up after a while, especialy on a engine that has just been overhauled. if everything checks out you may need to start lookin at the ignition pulse generator and the control module, check the timing with a timing light and make sure your timing is on the F mark with the engine at a idle.

P.S. i would check everthing except the ingnition control module and the pulse generator fist, these two things are the hardest to check, due to the fact that they cant be easily tested you have to use a order of elemination to tell if one of them is bad and it is a pain in the butt. hope this helps and good luck

[SnowFlake]

Where is the oil pump striner in the engine cause mine is apart and i think i should clean it since its apart.

[mojoe2878]

look on the right side behind where the clutch cover goes, at the very bottom of the crank case in between where the clutch basket is and the oil pump, theres a 10mm bolt there that is holding a black piece of plastic in place, unbolt it and slide the plastic tray out, thats the oil pump strainer. dont be too suprised if it has metal shavings in there, thats normal as long as they arent big chunks, whenever you get the motor back together and are through the break in its a good idea to clean it out again because it will have more shavings in there after the new parts mesh together, it just helps keep the oil flowin better.