[JPM]

Hello all,

I own a 2008 Sportsman's 500EFI. Bought it brand new and never had an issue until now. Took the quad hunting a couple of weeks ago and it starting backfiring and losing power while riding the hills.

As soon as I got back to civilization, I took it to reputable local shop. The shops owner had the thing for two weeks and could not find anything wrong with it. Tested the fuel pressure, electrical system and tried to get the machine to give him the same symptoms with no issues. Yesterday, I took it out for a couple hour ride with my wife and it started having the same problems at about the hour and a half mark.

The fuel (Supreme Unleaded)is brand new from the pump. I was thinking about replacing the fuel with a lower octane, but if it was the fuel, wouldn't it do it all the time, from starting it to the end of ride?

Any pointers would be greatly appreciated.

 

[Craigaz]

I had a similar problem with my '06 500 EFI and it turned out to be the fuel pump in the tank. Dealer will only sell pump with the tank as a complete assembly, which totally sucks. I found a thread somewhere on this forum that told which off the shelf regulator and pump are a direct replacement. I did the replacement about 6 months ago and my ride has been running like a champ ever since.

Hope that helps.

 

[Bruce!]

Welcome to the board!:med:

 

[mr_chow]

G'day JPM,
a couple of problems ive had with mine have been backfiring out the intake and popping and backfiring out the exhaust under med- high rpm. the intake bang was caused by a munched exhaust cam lobe and the exhaust bang was caused by the magnets coming loose on the flywheel which i fixed by jb welding the magnets back on.
hope this helps mate.