Backfiring...

[AmnChode]

Ok...I'm fairly new to working on a bike and I am trying to learn all I can. In this learning experience I heard that the AIS can cause popping and backfiring, which I have. Initally I disregarded it as I planned on plugging it. But after a little further inspection I have noticed that it only occurs on the right side (at least when on the side stand). I found this out by reving the engine and letting off quickly, which in turn causes the backfire, and as soon as I let off, I glance at the pipes to see which one it is occuring with.

 

With that said, would it still be the AIS (as I haven't plugged it yet) or could I have a leak somewhere on the right side. Bear in mind, I haven't put it on a jack to level it yet, I am just fishing for what to possibly look for. And for a little history on the bike, from my understanding it had sat for quite a while when it was trying to be sold and I am not to sure how ofter it was ran during that time. I know not enough for the battery because it was bad. But it does have a fresh tank of gas...

[1BigDog]

Sounds like you need a good plugging there.........

 

Seriously, I plugged my 99 and the popping went away. I personally used 5/8" heater hose caps from Help!, those red carded odd parts you see in auto stores like pep boys. They fit right in snugly.

Also, toss in a can of Sea Foam carb cleaner and run the bike. Makes a big difference.

[Al Bates]

Popping or Backfiring. AIS (Air Induction System) January 8, 2004

 

This my not be the solution for everyone. This is how I corrected the popping or backfiring on my 2002 RSV. I purchased the RSV used, with 6000 miles from a dealer. On the way home I heard a popping or backfiring noise. I returned to the dealer and explained the problem to him. He kept the bike for 4 days. When I got it back it started popping again. Then I decided to look into this myself. After looking over their work, I have to say I was surprised by the poor workman ship. They halfway plugged the AIS system and said it was fixed. I then researched and figured out how the AIS works. To make a long story short, I found that fuel was leaking from the carburetor and running down the carburetor manifold into the vacuum port then down the vacuum hose to the back AIS air cutoff valve. This 1/4 inch vacuum hose controls the AIS air cutoff valve. What I found was that fuel (maybe from setting) ran down to the AIS air cutoff valve and prevented it from working properly. My solution was to plug the four AIS cylinder ports. That's where it all starts. (See picture). By plugging the AIS tubes that would eliminate the AIS from that point on. Now all the AIS can be removed. (See other post on how to permanently plug and remove the AIS). I decided not to go this route because of the warranty. This is my fix. Follow the rear steel cylinder AIS tubes down (see picture), there will be a short 1/2 inch rubber hose at the end of each pipe. Remove the short rubber hose and place a marble or steel ball bearing into the 1/2 inch rubber hose (lubricate if you wish). After installing the ball bearing or marble, move it up until it touches the steel cylinder pipe where the rubber hose slips back onto the steel pipe. Replace clamps. Do this to both AIS rear cylinder pipes. Next I placed a small steel ball bearing into the 1/4 inch vacuum hose from the carburetor manifold, this is on the opposite side next to the carburetor. Slide the 1/4 inch ball bearing next to the manifold port. Install the clamp (see picture). I did the same thing to the front AIS tubes. The fronts are arranged a little different. I did not find any fuel in the front AIS air cutoff valve. The front requires pulling the bottom of the radiator away so I could get to the short 1/2 inch rubber hoses. I had to drain the radiator first. A friend did only the rear. We spent about 15 minutes and it corrected the problem. I hope this helps.

AL Bates

[Freebird]

A really good carb sync has also been known to stop the popping. That is the easiest thing to start with.

[AmnChode]

Alrighty...I'm gonna try to get it plugged up this weekend (at least the rear) and I'll follow up with the results here. Thanks for assist...

[AmnChode]

Worked like a champ...got delayed on getting it done, but on a whim tonight, me a good friend of mine plugged both front and back and now I have the the sweet sound of no backfires...Now to bore out a couple of RK muffs and I'll be good to go...hehehe:cool10:

 

Thanks for the help guys...