Been working on my father in laws 06 rubicon 500 es. It has a problem where once it warms up a bit it will spit sputter bog down even stall when trying to take off in 1st gear. It is electronic shift but shifts fine. I cleaned all jets in carb twice,checked float blew everything out good. very clean carb. Drained all gas in tank put new gas in checked small filter going into carb. I have even tried adjusting the air fuel pilot jet. Nothing has worked. The slide, needle and diaphram are fine everyting checks out. Air filter is good no leaks anywhere. It will go good if you pull choke when it starts doing it. So its obviously not getting enough fuel but what next? If used to run great

 

You'd be a lot better off on this by posting in the Honda section where those guys live and breathe.. Honda is the main one that uses Keihin carbs.

 

How did you clean the jets? Usually just soaking the jets in cleaner doesnt fully clean them. Did you carefully run a small wire thru the pilot jet ( or replace with new)? A small wire from a wire brush works well, though I use jet reemers? Sounds like the pilot is still dirty, also, change the spark plug and ensure the plug boot is all the way down on the spark plug. I would guess a Moderator will move this to the Honda forum.

 

Yes i did use a wire to clean the jets. Yeah stupid me put it on polaris forum. Oops

 

Change the plug. I had one in here a few weeks ago, thought it was the carb...carb was clean. Felt the spark plug boot, was loose ( owner must have done this ), pushed boot all the way down...same thing. Changed the plug...ran perfectly. Loose boot caused the plug to partially foul. I repair ATVs.....I should have known better....

 

Ok i will try that. I just figured it was fuel related because it went ok with choke on.

 

So did the one I repaired...lol...or it seemed to. The plug was like $12...IR.

 

I just wanted to let you know you were dead on about changing the sparkplug! It fixed the issue. Runs great now. Just used ngk bkr5es think it had a 5e in it. The plug that came out was black,black. Wish every fix was this easy its been stumping my father in law for months with the sputtering issue!!!Thanks again

 

It has stumped me before as well!! Glad you got her going....Awesome! Thank you for posting your results....can help many others as well!