re-jetting for aftermarket pipes

[Steve Bakken]

So the bike I bought this spring has a set of cobra pipes on it. It's an 01 Honda Sabre 1100. I would hope and assume that the previous owner re-jetted for the increased flow, but during decelleration it crackles and pops---alot. Not sure if this is indicative of a lean condition or not. Anyone have a rule of thumb as to how many sizes up from stock a guy needs to go with aftermarket pipes?

[osok]

Check out Cobra HSOforum, would help if you knew what model of pipes were installed but surfing around you should get an idea. I installed new pipes (V&H) on my Suzuki last season and it was recommended I install @least a stage 1 carb kit.

But back to focus....... Popping @ deceleration sounds like a lean burn condition, Crackles....well that could be just be the pipes themselves. I don't know of a good rule of thumb for this, but I'll be watching this post to see if a guru steps up.

Good luck.

[PierBridge]

I would contact the exhaust system manufacturer for starters. They should be able to provide you with technical information specifically for your application. You may, or may not, have to re jet the carbs.

Also there are TON's of Honda forums out there with some serious bike Guru's hanging willing to help. I agree it does sound like a possible lean conduction.

[snapjigger]

Just adding pipes should not require you to rejet. You should be able to just adjust your a/f screw. If you want to check to see how your running, get out on an open stretch. Run at 50+ for a bit then pull in the clutch as you hit the kill switch. Pull it over and pull a couple plugs out to sere what they look like. If you are running lean they should have a white look to them. Rich or fat and they will be dark. Hope this helps. Scott.

[Macgyver55]

Just adding pipes should not require you to rejet.

Its totally dependent on the pipes, each one is different depending on the backpressure. Judging by the fact that he has the symptoms of being lean, it sounds likely he will need to rejet.

[maj330]

You need to go up a pilot jet size or two to get out of popping (too lean) when you shut the throttle. Check the spark plug electrodes too as the PO may not have increased the main jet size to match the exhaust flow of the new pipes.

[pike_buster]

Steve whats your email address, i have some info i can send you. I have on 05 sabre.

[Steve Bakken]

It's [email protected]

[pike_buster]

i just sent you some information

[upnorth]

I know the V star bikes have a AIS system that adds air to the exhaust side of the combustion process that is supposed to burn any unburt fuel in the exhaust. Getting rid of that gets rid of most if not all popping/backfiring. A quick search and looks like the shadows have something similar. May be worth the effort to look into whether or not it can be modified to prevent the backfiring.