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I have a question. Just would like to know if it a bad thing if my 03 mxz 800 backfired and flames came out my mbrp trail can. Could there be something wrong. It was my first ride with the mbrp trail can on. After it backfired it was a little hard to start but when it start it ran really good again.
 

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Check to see if you have any cracks in your y pipe. Also check your crank seals to make sure they didnt pop out. Had the same problem on my 2005 500ss.

Good luck!

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Every once in a while mine will backfire out the muffler after a hard run when I shut it off without letting it idle for a minute.

Ive seen a lot of sleds do that.
 

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Let it idle down for 30 seconds or so after a hard run. What happens is fuel/air mixture is still drawn through the engine after the kill switch kills the spark. It gets pumped into the exhaust where it is ignited by hot carbon particles, KABOOM!!!
 

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Discussion Starter · #8 ·
I see. That's the first time it has happen to me plus its the first time I was riding my sled really hard too. Thanks guys for replying and helping me out with this.
 

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What ive found to help too is when your going to shut it off put the choke on to get the rpms down to like 1500 or so amd let it idle there for like 30 seconds and then shut it off. Should stop any problems.

Good luck!

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Mine did the same thing, wait a little bit before shutting down, your side panel will appreciate it also...I ended up pulling that can off and putting the factory back on, it sounds so good and I felt the mid range was a bit stronger however the low freq droaning got to me, ear plugs helped but ended up back at factory muff.
 

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I have an '05 800, mine will backfire if i shut it down before the idle settles back down to normal. Probably not anything to worry about, its not uncommon for a two stroke... especially if its after a hard run and the pipe is good and hot.
 

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My 03 800 has done it for 5 years, and you would think a person would remember after a long wide open pull let it idle for 30 seconds before shutting it off. Scares the doo doo out of people around, but I've kind of gotten used to it, and just mutter kind word about myself when I do it.

Thumper
 

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13 years with my 03 occasionally scaring the poop out of others and myself when it sounds like Ive been shot...you would think I would remember...you would think I would remember...lol Hardy
 

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I remember back in the 90s, they used to have a race in Bingham Me, called the Wyman 250.

I remember at the first race and first pit stop..

The riders would come sliding into their pit stops for gas and their pit crew would start putting gas in the sleds as soon as they came to a stop.

Some crews would spill gas while frantically pouring it in the sleds.. then Bam.. the backfire.. and the sleds would instantly catch on fire.

They ran out of fire extinguishers that year lol.

A lot of skidoo's did not finish the race. :(

The next year they changed the rules so each sled had to stop for 5 minutes.
 

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Let it idle down for 30 seconds or so after a hard run. What happens is fuel/air mixture is still drawn through the engine after the kill switch kills the spark. It gets pumped into the exhaust where it is ignited by hot carbon particles, KABOOM!!!
This can also happen with EFI two strokes when letting off the throttle. The 2004 SDI was notorious for doing this. We finally checked the injectors to find it was running far too lean. The pipe and muffler would grow too hot and POW lol

It took several years before I found the documentation from BRP in a bulletin that explained the problem with running the engine is a particular load range that would cause the exhaust temps to grow too hot. What I found funny was the wording. I'm only paraphrasing, but the message said if one insisted on running this cruising speed for a prolonged period......when they shouldn't.......to get the updated map. It was the closest wording to calling people stupid that I had ever come across from BRP. My initial thought was......why don't you help us stupid people by giving us access to better information like the bulletins???

BRP, Arctic Cat, and Polaris are at the pinnacle of two stroke engine design. What they understand and the struggles we have to go through just to keep-up with what they knew 10 years ago is ridiculous. The last Piston Failure Analysis Guide is so old that most members on DooTalk didn't even own a sled back then.
 
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