Backfiring

[350Kris]

What is the leading cause of backfire when I engine brake (decelerate)??? I'm talking about a 350x with stock motor, carb, and exhaust. The muffler has the small plate removed from the back. Could that cause it?

[yamaha200E]

well i heard somewere that timing has a big thing to do with it. but i dont know much bout honda.

[ejc042]

The timing can cause it to backfire. If you have a manual it will explain exactly how to check timing.

[200x Basket]

running rich and valve overlap also causes backfiring. i dont know about a 350x but it could be perfeclty normal. it is normal on some engines. **edited by moderator**



**Warning - You know better than to bait someone into an argument.

[200x Basket]

LOL, he self proclaimed it, that is not baiting, it is just repeating his words!!! :D

there was no cussing, no name calling, and no lying, i think you need to relax a tad and have some fun.

[TimSr]

LOL, he self proclaimed it, that is not baiting, it is just repeating his words!!! :D

there was no cussing, no name calling, and no lying, i think you need to relax a tad and have some fun.

Im not into loopholes and technicalities, so please dont quote the rules to me. You are trying to start a fight, plain and simple. If you want to "have fun" with somebody, selecting someone who you obviously have a problem with, and who obviously has a problem with you is not a good idea, and your intentions are obvious. You wanna fight, do it in private.

[MR ATC]

backfiring is caused by excesive unspent fuel that builds up in the exhaust and gets ignited. stock 350X's are jetted rich and are known to backfire when decelerating. anotherwords its normal.

Tim, i have no problem with basket. or anyone else.

[FullBore]

Another sort of noise when decellerating can be caused by the mixture being a bit on the lean side, it is heard as a soft popping, not bangs and is also caused by air leaks in the exhaust system, usually on cars, but sometimes heard on bikes.

Nat

[groundfly]

Not to argue or disagree with anyone, but I thought a lean mix would make an engine backfire too, That's why some carbs have an air cutoff valve. When the engine suddennly decelerates the mix becomes lean, which can cause popping and backfiring, then an air cutoff valve shuts-off some air flow to make it temporarily rich to stop that. Now I'm not saying i'm right and i know nothing about the machine at hand, just kinda puttin in my 2-cents.

[Dirtcrasher]

Call me a crack head.... But after putting on a COBRA pipe - 250SX it backfired like nuts, especially after a hard run. It was lean and I tossed in a 350X #138 main and it still popped but had better top end. I turned out the air screw 1/2 turn and the deceleration backfire stopped almost completely - yet were all told the air screw on affects idle to 1/4 throttle? :? Why was that?

[TopGear1]

Kris,
knowone seemed to touch on the basics.

#1 Fouled or improperly gaped spark plug
#2 Improper ignition timing
#3 Improper Carb main jet selection
#4 Weak ignition coil, CDI unit or Pulser generator
#5 Obstructed fuel line or shut off valve
#5 Improper ignition advancer unit
#6 Clogged fuel cap vent or fuel filter

process of elemination...good luck! :-D

[Wickedfinger]

Someone copied their Clymer .....

[TopGear1]

I did that all from memory.... :shock: ...LOL