Hey Guys
I've got as 2003 Prairie 650 that's popping back thru the carbs. The bike's never sat more than a couple of weeks without running. I just completely serviced it with oil, oil and air filter and new plugs. Has fresh gas and a hot battery. It's starts easy and runs great but has a spotatic (but consistent) pop back thru the carbs. With the air filter off you can see a millisecond blue flame (like natural gas) pop in the carb. Has about 1200 miles and 430 hrs and as far as I know never had the valves, timing or carbs touched.

Any Ideas?

 

Do you know for sure that the bike has never sat more that a couple of weeks? If it's back firing through the intake, probably a lean condition. Wouldn't hurt to take the carb(s) off and inspect them.

 

Had one doing similar but it had been sitting for some time. I took it out for a good hard run and basically run the **** out of it for a good 1/2 hour. Problem solved hehe

 

Yep, pilot jets clog and engine runs too lean at low rpm.
A couple ways to solve.
> Add carb cleaner into fuel tank. This may or may not fix.
> Take out pilot jets and clean it out with a thin wire. This always fixes.

 

Have an 02 650 & mine does the same thing.Got in toutch with Kawasaki,& they tell me that it normal.Say there is nothing that can be done about it.Had a Kaw. dealer work on mine & still has problem.