maximus070301
New member
when my viper is cold and i start it it will start but it backfires any ideas why,other wise it runs good.
Choke on or off? Sound like the exhaust or intake side?
Could be too lean (should backfire through the carbs), fix would be to turn your fuel screws out more. Could also be flooded from worn needles/seats. This allows fuel to run into the motor while the machine is sitting, once started it all gets ignited. Fix is obviously to replace the needle and seats.
Anyone else?
Could be too lean (should backfire through the carbs), fix would be to turn your fuel screws out more. Could also be flooded from worn needles/seats. This allows fuel to run into the motor while the machine is sitting, once started it all gets ignited. Fix is obviously to replace the needle and seats.
Anyone else?
maximus070301
New member
choke off.once sled is warm and you turn it off and restart it, it wont backfire only after it has sat for an hour or so.
Sounds like my later comment then, but others on here have more yami experience and know a lot more then I do. Wait and see what they say before you go out and buy any parts.
yahadriver23
New member
Try letting it idle a little more before you just shut it off, i find if i run it and shut it off quick, the next time i start it up it will backfire (only happened a few times)
I let it idle for 30 secondish like i should after riding it for a few hours, and start it up a few minutes later it is fine.
I let it idle for 30 secondish like i should after riding it for a few hours, and start it up a few minutes later it is fine.
Yama49601
New member
yahadriver23 said:
That's what I was going to suggest. I've never had the problem but the local "dealer" told me (at least for my motor) that that backfiring is normal and to let it idle down before you kill it to keep it from doing that.
I know what you guys are talking about, but I'm not sure it’s the same as what MAXIMUS is describing. He's talking about a cold start after it sits for 1+ hours.
Your talking about a hot/warm restart of an over fuelled motor, cause by hitting the kill switch before its reaches a stable idle. Un-burnt fuel is forced into the pipe where it evaporates waiting to explode the next time to provide it with the means. That said, if you let it sit for more then 15min, it dissipates and will not cause a backfire. You are right though; it is a very good idea to let your machine idle for a minute after a hard run to prevent this. I’ve herd stories (but never seen) of guys shutting them down at 5000RPM after a hard lake crossing and blowing the crank seals out of their Ski-Doo when it backfires. LOL.
Your talking about a hot/warm restart of an over fuelled motor, cause by hitting the kill switch before its reaches a stable idle. Un-burnt fuel is forced into the pipe where it evaporates waiting to explode the next time to provide it with the means. That said, if you let it sit for more then 15min, it dissipates and will not cause a backfire. You are right though; it is a very good idea to let your machine idle for a minute after a hard run to prevent this. I’ve herd stories (but never seen) of guys shutting them down at 5000RPM after a hard lake crossing and blowing the crank seals out of their Ski-Doo when it backfires. LOL.
Thumper1
New member
speaking of a skidoo backfire. we were standing outside four seasons bar on namakagon and this dude pulls up on skidoo something, shuts it off, and asks were is the closest place to get gas. we tell him and he pulls the rope and BOOOOOMMMM. scared the blue out of us. i'm not sure a pipe bomb would have been any louder.
the only time mine has backfired is when the pilots were plugged.
the only time mine has backfired is when the pilots were plugged.
maximus070301
New member
thanks for the info,as for more details if i run it for a half hour or more so it is warm i can turn it of as many times as i want and restart it right away with no problems,but if i get lunch and a beer (or two) and try to start it thats when it will backfire,i do let it idle down,so i dont think thats the problem.any other guesses.thanks guys
woolyviper
New member
is it backfiring once (bang) or is it coughing like it's lean? Does it take a lot of cranking to get it started? take your exhaust and muffler (silencer) off and see if there's something restricting it towards the end. If the unburned mixture can't exit the exhaust freely, it will ignite inside the pipe.
Here's my take on this...if you just let it warm up more before (5-7mins) you give it gas-does it still backfire...if not, thats your answer...If she still backfires, then you have other issues...how many miles on it, is it stock, fuel consumption...I would pull all the plug, (cold engine) bring each piston to top dead centre, use a small clean flatblade screwdriver and wiggle the piston-side to side...if there is a little resistance thats good...that means that the rings are free and not carboned up and stuck on the piston...if it slaps around quite easily, then that tells me two possible things, a) rings are carboned up and you need the free them with some seafoam...or, b) the rings are collapsed and/or skirts, causes the charge of fuel to blow up around the piston and backfire...It most likely does not happen when things are warmed up and fully expanded...do a cold and hot compression test...compare the numbers...I am no expert, but this would be the way I would approach it...P.m. mrviper700...this t.yer is the real deal, he will have the answers...good luck and post your results...maximus070301 said:
marty f
New member
pilot jet!!
my srx has only backfired once due to the pilot jets gummed up,i would check the jets before anything else trust me
my srx has only backfired once due to the pilot jets gummed up,i would check the jets before anything else trust me