Hi all,
I'm new here, but have a question. I have a 2005 Polaris Predator 50 that starts good and runs approx. 10 minutes and then quits as if you turned it off and will not start back until the engine gets completely cold again. I bought it used and it used to run longer than that but did the same thing and the running time has gradually reduced as time has passed. Anyone have any suggestions?
Thanks

 

Welcome! Service limit shows to be 115 psi on the 90 (don't have the 50 pdf manual) but would suspect it to be at least 100 psi. If compression is lower than that,probably time for a new top end.Hard to get a compression gauge hose in the cylinder due to the frame in the way,but a small adapter helps. If it's getting harder to start especially when warm this a is a good sign the rings aren't seating against the cylinder walls. You can actually get complete complete cylinder/piston kits cheap for these. Just an example here. Big Bore kit 70cc 47mm for Kasea ETon Aeon Polaris 50cc ATV | eBay Plus here's one even cheaper. http://www.ebay.com/itm/replacement-...30790363492%26 Actually cheaper this way than to bore your cylinder out and replace with an over size piston,rings and gaskets through a dealer or online sites.
OPT

 

Thanks old polaris tech, I don't think the top end needs rebuilt. It hasn't been road very much at all. The atv is all original and hasn't even wore the little **** off the tires. It seems to be a firing problem and I'm definitely not a mechanic.

 

I'd check compression just to eliminate it as a problem first. You can also pull the black cover from the stator area and clean up the pick up coil and if you have a puller for the flywheel,just pull it and clean the stator area along with the inside of the flywheel.I have resistance checks on the 90 which should be close to what the 50 should show.
Coil tab to frame ground 0.2-0.3 ohms Coil tab with plug cap on 8.0 to 9.3K ohms
Coil tab to wire with cap off 3.0K to 4.2k ohms resistance
Stator specs: Black to white/red 450 ohms
Black to Black/red 800 ohms
Black to Yellow/red 0.5 ohms
Black to white 0.6 ohms
Black to ground 0 ohms
You can also check the coil mount to make sure it's grounding good and also pull the black wire from the cdi to eliminate the kill circuit as a problem. Could be any of these if you rule out any mechanical problems. Most problems I had on the 50 and 90's were stators shorting out from water and dirt,plus just over heating I believe from lack of good air flow. OPT

 

Old polaris tech, should the resistor on this bike be getting to hot to touch on this bike?

 

The resistor block can get a little warm. Have had guys replace them,but still had the same problems.I've never heard back from anyone that replaced them that it solved their probem such as the one you're having.

I've never had to replace one myself,but doesn't mean they can't be faulty,but i haven't found any checks on the ceramic resistor in the manual. I rechecked the schematic and does show only that the resistor is 4.3 ohms, but doesn't show any tests on it. OPT