just bought a rough 05 450r kicker for $1400. it runs but when im not reving it just stalls. ive adjusted the idle screw and i put on a Works Connection air/fuel mixture screw. ive adjusted both back and forth but no luck. it has fresh gas in it.

for some reason smoke comes out of one of the carb breather tubes and another tube that goes from the motor into the side of the air box. it has a full hmf and uni on it and i dont think its jetted.

i think the problem may be the air fuel screw because before i put the aftermarket adjustment screw on it idled fine. maybe this is screw is meant for a different carb? or maybe im not turning far enough or too far? please give me some advice and info on what i should do any try. i plan to clean the carb out tomorrow. please let me know how far the air/fuel mixture screw should be out. thanks alot.

 

Does it stay running with the choke on? If yes then your pilot jet (the one with microscopic holes) is probably partially clogged. You can keep it running by giving it throttle because as the throttle moves past 1/4 you are generally off the pilot and on the needle jet...


The pilot will be inside the bowl next to the main and can be a real PITA to get out as they are almost always sunk in deep an require an "exact" fitting screwdriver to get it out without stripping it...hence the reason most don't clean it...

 

yeah i cleaned the carb and it was clogged. it idles now but its not a constant idle. it goes up and down every few seconds even though im not revving it. what would that be caused by?

 

Couple things come to mind:
1) you could have an air leak in your intake system - some spray carb cleaner around the reeds/intake boot while running and listen for RPM change, others pull it off the machine and inspect for holes/tears (hold it up to bright light)
2) your float level may be incorrect (did you accidently bend anything while cleaning the carb?)
3) you didn't clean it as well as you thought and there's still some clogged holes in that idle jet (I've invested in a ultrasonic cleaner for this very reason)
4) inspect your reed pedals for cracks & chips...


hope this helps...

 

the jets are all good. the small rod for the accelerator pump on the carb is bent a bit though. could that be it? i will try the other things

 

I was thinking more the float itself...some have metal tabs and can be tweaked (bent) causing the wet float level to be higher/lower...

 

it all looks fine to me.

 

Does your float have a metal tab or is it all plastic?

 

its all plastics but there are metal tab looking things under it. is that what you mean? i dont know haha but it all looks ok

 

That's most likely the float needle/clip...don't bend those!!! :P


So...time to look elsewhere...did you inspect the intake system (rubber boot & reeds)?


If all that looks good time to move to the harder stuff...you'll need to confirm valve lash is in spec on both intake & exhaust...