Backfire when hammering throttle

[yamamarc]

I haven't had a chance to take a look at my sled yet but wondering if anyone ever got a backfire when hammering throttle?

It just started doing this randomly! When I come to hammer throttle from a dead stop I sometimes get a backfire!! Doesnt happen everytime just randomly!!
Any thoughts?
Marc

 

[fatchance]

Only time i ever had it backfire is when it was running very hot.... 212 degrees and beyond.

 

[yamamarc]

Only time i ever had it backfire is when it was running very hot.... 212 degrees and beyond.

Everytime it done it was running at operating temp. Just warm outside a 8 to 10* c
I could do 3 pulls all ok the the 4th I get a backfire

 

[Mitch Desorcy]

When I hit rev limiter on my Viper it sounds like a backfire. When I'm hard on the throttle. 240 HPW turbo.

 

[jonlafon1]

How much fuel in tank when this happens? Also by any chance you added octane boost after symptoms? Is sled stock? I have seen this only two times in 7200 miles on mine. Some feel this happens when very low fuel levels in tank. Or possible a bad fuel situation. Not sure what mine was but I feel it was a octane issue on mine. My 2 cents

 

[yamamarc]

How much fuel in tank when this happens? Also by any chance you added octane boost after symptoms? Is sled stock? I have seen this only two times in 7200 miles on mine. Some feel this happens when very low fuel levels in tank. Or possible a bad fuel situation. Not sure what mine was but I feel it was a octane issue on mine. My 2 cents

It is possible! I just filled with 93 Oct and some torco I haven't got to try it again yet
Sled is tuned

 

[YukonMP]

How much fuel in tank when this happens? Also by any chance you added octane boost after symptoms? Is sled stock? I have seen this only two times in 7200 miles on mine. Some feel this happens when very low fuel levels in tank. Or possible a bad fuel situation. Not sure what mine was but I feel it was a octane issue on mine. My 2 cents

If a guy has some water in the bottom of his tank he will pick up more of it as he gets down to the bottom so low fuel is basically a bad fuel situation.

 

[DooZ]

RPM spike hitting rev limiter? Hot motor marginal octane fuel? Low fuel quantity/quality? The new 93 with Torco should rule out the fuel, but the Torco may cover up for bad 93.

 

[klr650r]

If you guys figure it out, let me know I don't mind a good pop here and there LOL.

All kidding aside is the limiter system in this a fuel cut or a spark cut or a mixture of both?
I've never really found the limiter on mine.

 

[PowderFalcon]

My sled does this often. RPM bang on. tuned. beat on it down the trail. come to a stop sign... POW!!

 

[yamamarc]

Looks like it was the fuel!!! I just went out after filling with 93 and torco!!
Got one backfire on first run then did multiple runs and all good

 

[Doowithblue]

Low octane can do that coming to a road crossing.

 

[number1kyster]

Mine backfired on decell when it was new. It seemed to be when the fuel started to get low. My sled had the red fuel tank check valve. I drilled it out. The sled no longer makes the popping sound. I'm not sure if drilling the check valve helped or if the sled is just broken in now. Perhaps it was just a bad tank of fuel. All I know is it no longer does it.

 

[MUSKOKA SIDEWINDER LTX LE]

Also make sure plugs are gapped proper

 

[krm]

Excess fuel fumes in the pipe will do it .