Hello memberss. New to the page and really need some advice. I have a 2016 Polaris 800 Pro S Switchback all stock except for MBRP Trail Can. Rode 1200 miles last year no problems at all. This year first 100 miles worked great. Now every fifty miles I foul a plug on the mag side. Went through half a dozen plugs (BR9ES) on my latest trip and can't figure out the problem. Yesterday put stock pipe back on and still the same thing. All wires look good, nothing rubbing, lose, etc. Any advise would be great. Thanks
50 miles then fouled plug?
- Thread starter afveteran88
- Start date
I would start by checking compression but it could be as simple as running some injector cleaner through it as these sleds have no fuel filter on them! try running br9eya they are less prone to fouling. have you checked the spark to see if it looks weak? it could be the start of a cap or wire going bad.
I did run some fuel injector cleaner through it with no change. When I put a new plug in it I have great spark. Could that injector go bad? Or maybe coil?
Check the compression for sure!
You could also swap the coils and wires from cylinder to cylinder and see if you start fouling the other side. then you will know you either have a coil or wire problem.
If you have a dirty injector it can leak extra fuel and make it foul a plug. Injector cleaner might not be enough to clean it if thats the problem.
You could also swap the coils and wires from cylinder to cylinder and see if you start fouling the other side. then you will know you either have a coil or wire problem.
If you have a dirty injector it can leak extra fuel and make it foul a plug. Injector cleaner might not be enough to clean it if thats the problem.
yea I would check compression... if its good do what SRX suggested and swap the wirers... if the problem doesn't follow the plug I would check the reed on that side it could be chipped/cracked or just plain wore out... I have heard of the EV coming disconnected from the rack. does the sled run spot on with a new plug or still act a little funny?
It runs great with a new plug.
Well I guess you fixed it then! Disregard everything we posted above.
Right.....Until it fouls the plug again....
BR9ES is the wrong plug, shouldn't make much difference but correct plugs may help.
bpr9es are the factory plugs , I would still try the EYAs they foul less but their is an underlying problem I would bet...check the above list and let us know what you find!
A
awful knawful
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my buds was fouling plugs. ended up being reeds.
Ok so today I got a chance to check the compression. I have 100 psi in each side. My guage might not be the best but consistant. I checked my buddies sled which is the same year etc and his reads 115psi and 120psi. Going to swap out coils with my buddy and run it to see if it is the coil.
Are you stuffing the exhaust with snow when sidehilling on that side? Mine is prone to that. Fouls plug but then clears. Lightened clutching up a bit and it clears better. Thinking I better look closer to see why mine is worse than others. Compression, reeds, or exhaust valves or maybe even the pipe temp sensor as it seems to run rich quite often. Is there any easy way to prove the injectors?
Take a good look at your spark plug boots---I had the same issue with the pto side cylinder. turns out the connection in the boot was breaking. eventually the spring piece came out stuck on the top of the plug. easy to change the boot out anyways. My dealer gave me 2 new boots under warranty so i wont get stuck.
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