I just bought a 2002 grizzly 660. It was never ridden last year. It runs good, but it is hard to keep running while idling. Also when you are ridding it a full throttle and you let off the gas is wants to backfire. If anybody could tell me what might be the problem it would be greatly appriciated. Thanks Mark

 

i dont know if this is your problem but when my raptor sat for one year i hadda clean the carbs and i mean clean them there was crap all over the place i would say its a good spot to start

 

It may run a bit crappy til you can get fresh gas in it. Try turning up the idle speed, a bit ..that might help the idle. To get rid of the popping exhaust on decel...turn the mixture screw 1/4 turn richer. The popping means the idle circuit is too lean.
If after running all the old gas thru it, and getting new fresh gas in it, it still doesnt idle good...then the carb probably needs a good cleaning. Especially the pilot jet, which can cause both of those symptoms.
Welcome to the forums

 

yeah, if the gas is old, get rid of it. Check to see if the air filter is clean and have the carburator cleaned out and adjusted.

 

Absolutely,

Get rid of the gas, clean the system out and the carb.

SilverBear

 

Now there's one I haven't seen in a while. I assume the 727 project is finished?

 

Definately take the carbs off and clean them. It may be easier to get the carb kits if they are real gunked up. Also clean out your gas tank. When that fuel turns to varnish you get little pieces floating around that clog everything up. I would say one of your jets is plugged with residue from old gas. Your floats will probably be sticking as well.

SilverBear - Great web site, I have it on my favorites. Lot of good information.