Sound When Rolling off the Throttle

Hello,
Maybe someone hear can help me understand whats going on with my bike.
I have a 98 YZF 600, stock with the exception of a D&D slip-on. When
I roll of the throttle at mid/low RPM (3000 - 9000)I hear what almost
sounds like small backfires. A glug-glug kind of sound if you know
what I mean. My uncle (a mechanic) has commented on the rare occasion
that I've seen him with the bike that it sounds like its running rich.
Anyone know the cause or if its something I should be concerned
about. Thanks in advance for constructive comments.

Cheers,
JJP

 

Thanks for the advice, checked the plugs - nothing looked out of sorts
to me either rich or lean. Any other ideas?

JJP

 

Re: Sound When Rolling off the Throttle

Group: rec.motorcycles.tech Date: Fri, Jun 11, 2004, 11:52am (EDT-3)
From: (JJP)

Some bikes have a "pair" valve, to meet emissions requirements. (smog
pump) Fresh air is injected into the exhaust ports, and this causes an
afterburn, or "popping" upon decelleration. If your bike doesn't have
one, then you are simply lean in the low end circuit.