This is a long story so will condense as best I can. Quad ran fine to 5,000 rpm, but began missing if i gave it full throttle. Factory carb had been rebuilt by Polaris shop 3 years ago. Replaced fuel filter. Mysteriously it idled faster. Replaced OEM carb with Caltric carb which looked identical. Runs fine for 20 minutes or more but then bogs down and will only idle. Cuts out if i hit the throttle. If I let it idle for 15 seconds it comes back to life, then repeats the problem 15 minutes later. Ran with fuel cap loose and no help, so not the tank vent. Seems to be fuel starved. Have a new fuel pump ready to install, and finally found info on correct low speed jet adjustment (1 1/2 turns out to start). Could this problem relate to an improper low speed adjustment? Any ideas on fuel pump, fuel line routing? Never had this "bog out then run fine" problem before Caltric carb. Any ideas, no matter how remote will help.

 

low speed circuit only does maybe to 1/4 throttle then main jet does there until full throttle. did you try running it with the choke to see if the extra fuel made it run better since you think it might be starved for gas? changing fuel filter should not have made it idle faster, maybe like getting more air then needed or not enough gas? assuming you put the correct filter on and the correct direction (I have seen it put on backwards) . just trying to figure why the higher idle for no reason. changing carbs should not have been needed or rebuilt on the old of a bike unless something went wrong/broke. usually they don't wear out in 10 years. imo by any chance have the valves been adjusted? how many miles on the bike?

 

Stendori is right, changing carbs shouldn't have been needed unless something broke. The OEM carb is better than the Caltric, but since you already have it, are the jets the same?

 

Thanks for the replies. Rebuilt carb first time because fuel was leaking out overflow. Needle jet bad. Second time 3 years later, after 10 or so seconds of idle, engine would die. It would restart after some cranking. Rebuilt at Polaris dealer that time. Put on Caltric carb because motor was cutting out/hesitating when I hit full throttle. Thought it was starving for fuel. 2100 miles. No, valves have not been set. I know, they should have been set every 100 hours, dealer wants $225. Tough for me to come up with that kind of money. After watching video, I can do that myself, but do I have to tear all of that plastic off again or can I get at them by removing the seat and side covers?

 

Follow up 'cause I missed some things. Running with choke makes it run rich and miss which is what I would expect. Did not check Caltric carb for jetting but will be removing soon. Can you give me jet numbers in case I find something wrong. Thanks for the help, men.

 

well it would not be starved for fuel then if choke makes run rich which it should do. the jets should be the same as the stock carb that you had. the pilot jet is the jet that runs from idle to 1/4 throttle.