I have owned three sg and every single one would occasionally pop, or hiccup out of the air cleaner, what causes that?

 

I would like to know this as well, I originally thought it was tune or an intake/exhaust leak but ruled out leaks and tune.

I normally see it when cruising in 4th gear going 30-35mph (or 5th at 40-45mph) seems to be with low throttle low rpm (i think no tach) cruising.

 

Mine does it when warmed up and give it a slight rev while stopped at a light.

 

I assume you are all talking about carbuerated engines?

 

Mine is fuel injected and has done it a time or two. Kinda like a backfire out of the intake...

 

I have had both injected and carb do it. The efi bikes had two different tuners as well.

 

Same here . . . 96 Dyna FXDS with carb . . . cruising at 1800 RPM or so with warm engine and . . . Poof . . . pop out the carb . . .does this randomly about once every 5 or 10 minutes. But has to be just under 2000 rpm.

 

My carb does it every so often.

I have a gross name and call them Hog Queefs (sp)

 

The official name for what you are talking about is carb farts. (Not sure what you call em on an EFI bike) This happens due to the fuel mixture going lean at the time of the pop. This can be cured in bikes with the Kehin carb by swapping out the stock jet needle for one with more taper. Or, you can increase the slow jet one size and/or put a thin shim under the stock needle. I have done it both ways. Changing out to the N65C needle is the best way to go. Joe Minton just wrote an article the May issue of American Iron about this. I followed his advice, and it worked like a charm.

In EFI bikes, the cause is the same-lean mixture spot, but the fix usually requires re-mapping the fuel curve. This is more expensive than a $10 needle or slow jet change.