Popping/backfire

09500outty · #1 02-08-2010, 03:36 PM

I've got an '09 outty 500, HMF pipe(sounds great), Dalton clutch springs and custom snorkeled. fantastic atv. Problem is that there is a nasty backfire/popping sound comming from the air box and it is lacking power, what could be the cause? is it a possible exhaust leak?

kccamp · #2 02-08-2010, 04:21 PM

Quote: Originally Posted by 09500outty

I've got an '09 outty 500, HMF pipe(sounds great), Dalton clutch springs and custom snorkeled. fantastic atv. Problem is that there is a nasty backfire/popping sound comming from the air box and it is lacking power, what could be the cause? is it a possible exhaust leak?

Chances are you're running lean. You have to richen up your A/F ratio. I have an HMF on the way, and HMF told me that I may or may not need an EFI controller, so I am going to run mine without it first, and see how it runs. But if it backfires like yours, I am going to get a Power Commander 3 as most people on these forums swear by them. I also have just installed a snorkel kit, and it runs fine with just the snorkel kit on it.

A couple of people on these forums told me that these bikes run rich from the factory (well, the 800's atleast) so I shouldn't have a problem. I hope not.

09500outty · #3 02-08-2010, 04:33 PM

Thanks for the reply. The pipe sounds great!!!!. the quad was starting to pop before the pipe, quess I should have mentioned that. I put new fuel in and new plugs. is it a warranty thing to have them check the air/fuel mixure, or is it something else?

Col. · #4 02-08-2010, 04:57 PM

The shop manual says exaust leak or engine is running hot because of a lean condition.

800VTwin · #5 02-08-2010, 05:30 PM

popping in the intake side is lean. If this started before the exhaust install, I would check your fuel pump pressure.

rotax · #6 02-08-2010, 06:33 PM

My 210 650max xtp back fires when I come on to it and then let off quickly. The only thing I did to it was add a twin air filter.

cardiac · #7 02-08-2010, 06:46 PM

You may want to check your valve adjustment. Tight intake valves will cause just the symptoms you describe.

rotax · #8 02-08-2010, 07:28 PM

they adjusted the valves when they did the first maintenance but i will call them in the morning. thanks!

i know they did something to the computer for cold starts. might have something to do with that.

800VTwin · #9 02-08-2010, 07:54 PM

tight intake valves would also cause a rough idle and hard starting.

rotax · #10 02-08-2010, 09:56 PM

So you think the twin air filter is ok to have in there?