Backfire

[rwreuter]

Every once and awhile I hear my bike backfire, especially when I roll the throttle back. I am running 87 Octane fuel in it, if that matters.

Is the backfiring "bad" for the bike, will it damage it? I don't think the backfiring is a result of the low octane I put in the tank, but I could be wrong.

Any thoughts?

[Cluckemt]

Is it several little pops or is a big loud bang?

What kind of bike?
Aftermarket items? Pipes, air kit, etc

Popping on decel is normal, and is usually amplified with aftermarket pipes. Backfiring and the popping on decel is unused fuel being ignited in your pipes. It is a symptom of too rich mixture. Depending on the cause it can be normal or something to look in to.

[wild_deuce03]

There's all kinds of threads about this. Search under "marble" for a fix for it. I'm one of the few that actually likes the pop. Oh well, I never claimed to be normal.

[rwreuter]

It's a 900 Classic with no modifications. The pops are very sublte, nothing sounding like a balloon popping or anything.

Actually, I think it sounds rather cool. I just concerned about any damage it may cause.

[Cluckemt]

Yeah sounds like you need the marble.

Read about this and more here.

[greeneyess82]

U Might Be Running To Rich, Check To See If U Have A Gasket Leak. New Gaskets Cost $5 Bucks.

[SleekStreak]

Originally Posted by rwreuter

It's a 900 Classic with no modifications. The pops are very sublte, nothing sounding like a balloon popping or anything.

Actually, I think it sounds rather cool. I just concerned about any damage it may cause.

It's uncommon to hear pops on stock pipes, but it doens't mean anything is wrong with your bike. It just means that your bike is burning on un-ignited fuel in the pipe on overrun, which is how it should operate for the best emissions. You can get rid of the pops by various means, but it will mean you are increasing the hydrocarbons emissions.