my stock 650 all of a sudden is running like crap, it backfires thruogh the carb and has no power it acts like the plugs are fouled but i checked them and the are good and i checked the chokes on the carbs and they are good i also set my air screws at 2.5 turns out , it does run better with the chokes on for a little bit any ideas help!!!!!![img]i/expressions/face-icon-small-sad.gif[/img]

 

It sounds lean,if it back fires through the carbs.Also if it runs better with the choke on.Have you changed the air-box or you may have a air leak on one of the carb boots.

 

THE CARB BOOTS ARE GOOD AND THE AIR BOX IS STOCK THE JETS ARE ALSO STOCK IT USED TO RUN JUST FINE UNTIL THE OTHER DAY I TOOK IT OUT AND HARDLY MADE IT DOWN THE DRIVE WAY

 

Could have trash in the carb bowls,which could only let a little gas in the motor.Which would make it run lean.It could be a bad coil or plug wire.[img]i/expressions/face-icon-small-confused.gif[/img]

 

I,M going to start looking at the electrcial end of it i had to carbs off and looked at the bowls and even cleaned the them

 

Was the machine sitting for awhile? If so you may have some residue in the screen from the tank. Just a thought, trying to look for the cheap stuff. Also, if it runs better with the choke on, I would think it would not be an electrical problem.
I also have heard of the choke sticking on some of the Kawis.

 

F2
(1). Ensure your carbs are seated good in the manifolds, all retaining clamps are tight, and all your vaccum lines are hooked up corrrectly in airbox. If you previously had your needles out/apart ensure the slide springs are installed/functioning properly & not binding. Stick finger in throat of carb and depress slide, each slide should return propmly without binding spring noise & at same rate of speed.

Wth your airfilter removed, inspect airbox & snorkel drain lines to ensure they are not full of oil or water & drain if applicable.

(2)., Get yourself an air gun, start your engine. Near your Velocity stacks in your airbox by the cover attachment bolts there is a small brass looking hole near each stack. Not standing directly above the hole, shoot a shot of low pressure air in each carb hole to purge line.

(3). With engine off remove fuel lines from petcock and Blow low pressure air through petcock while cycling from off to on.

[img]i/expressions/face-icon-small-cool.gif[/img]

(4) Get some fresh Gas in your tank and shut off your fuel petcock when done riding, transport, or prolonged storage.
TuFF[img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]

 

I,ve elimanated the electrical stuff i,ve got new plugs and good spark , Ive charged the battery good, it runs just the oppisit of what it should with choke on it runs good with choke off it runs like crap i might start looking at the carbs the only thing i had apart is the bowls the chokes looked good

 

At what RPM? Low/High both?
I'll bet its the jets, pull them out and spray them down and check all the holes good. I'll almost put money on it, its dirty blocked jets. Everytime i've had backfiring its been plugged jets (lean condition)

 

it boggs at low rpm mid to low it backfires, i have 2 questions on the carb on the top between the 2 black round covers is a black plastic tee with a short piece of black rubber about 1 inch long is this suppose to hook up to something or just be open? question#2 i took the carbs off and removed the choke plungers one was in and the other was out would this cause these symtoms to happen?