Backfiring on deceleration

[wapam]

I have an '80 XS1100SG that backfires/pops while decelerating. It also hesitates slightly coming right off idle/slow speed. Once it gets past the little hesitation it goes like a bat out of he11. The bike starts great and idles great after warming up for a minute or so.

Bike has a non-stock Yamaha exhaust.

Before I dig into the carbs, does this sound like the right place to begin? I've owned the bike for a year, previous owner let it sit for quite a few years.

I appreciate any opinins.

[bikerphil]

hesitation & backfire

Try some Seafoam fuel treatment in the tank & see if that helps the hesitation.

For backfiring, check for exhaust leaks first, pilot screws might need tweeking.

[prometheus578]

"How long as I been doin' this?"

Backfire on decelleration means lean.
Lean at the carb jetting, vacuum leak at the manifolds or a leak in the exhaust system.
Like I asked.. been doing it forever, or just started?
Done any work recently on the bike?

[TopCatGr58]

As was posted in another recent thread, it's not uncommon for them to pop a little on Decel with aftermarket pipes, but this can be reduced with a little carb tweaking. You really should dig into the carbs to see what size jets you are running. ALSO, any other mods, like Indy filters, vs. OEM Airbox? Are the pipes 4-2 or 4-1, baffles or just straight open pipes??

Yes, Seafoam may help clear up the pilot/low rpm throttle response, but some other tweeking may be required, what do the plugs look like....bleach white, or tan, or black-sooty??
T.C.

[wapam]

Thanks for all the advice. Here is the exhaust I'm running:

http://www.oldbikebarn.com/Motorcycl...haust-System#5

I've owned the bike for a year, just got it running this spring. It's run like this the whole time I've had it.

Stock air box, new plugs, new fluids.

Should there be a gasket between the muffler and header pipe?

The previous owner didn't replace any jets, should be stock.

Thanks again.

[mro]

341-14613-00-00 GASKET, EXHAUST PIPE


mro
BTW, think John posted that they are available from georgefix on ebay, also most likely available from your local bike shop.

[wapam]

Thanks mro, these are the gaskets between the engine and header pipe, right? I was wondering if there is supposed to be a gasket between the muffler and header pipe.

Thanks again.