Just acquired a 2004 Polaris Predator 500. Unit ran great and popped off everytime, however it leaked oil between the crankcase halves.
Tore the machine apart and resealed the case halves. Repalced all gaskets and seals. I followed the service manual to a "T" with regards to torque, timing, valve lash, carb cleaning, etc. I replaced the spark plug, checked compression (120 lbs.), I am getting fuel to the carb and all the lines are free of obstruction. The fuel filters on the petcock are both clean. I tried fresh gas. The choke cable is operational as well as the throttle mechanism. I even did a load test on the battery figuring maybe the plug would spark when there was no load on the battery but not when the engine was building compression. It tested fine. It sits at 12.6 V to start and only drops to 11.7 while cranking. I checked all the wiring and the pulse coil along with the stator and reverse coil. The only thing I have not tried yet is a leak down test.

The thing just will not start anymore. It cranks and cranks and cranks with an ocassional teaser of a pop through the exhaust (gets the hopes up). I don't get it. Very confused. What am I missing?????

I have worked on stuff like this for several years now and have never experienced this yet.

Rule of thumb: Fuel,Spark,and Compression = Running Engine.

 

Check the kill switch.

 

Kill Switch is fully operational. If it wasn't I wouldn't have spark.

 

Are you 100% sure you have the cam chain in time?

 

hey bro I had the same problem and now I can't get it to dam start and I took it to a mechanice and he told me to replace cames and chain... But I haven't had time... Ey since you have a predator do you happen to have some perfomance parts layin around you might sale... Txt me to 701-331-0794 if you do... And good luck on ur atv..

 

Sheared flywheel key!!! Back in Kansas baby!! Runs great!

 

Sounds like the intake valves need adjustment. Huge problem on the predator. I'll bet if you towed the quad it would start right up. I have spent hours fiddling with mine and every time it boils down to the intake valves.