Extremerider
10-22-2014, 08:01 PM
I have an 04/05 TRX450R with an 04 CRF250R carb bored to 42.5 mm's. I am running a 162 main jet, 45 pilot jet, HRC needle with the clip in the 4th position, and a 55 leak jet. My head is ported, I have an HRC cam, CP 13:1 piston, and a pro design pro flow kit with a Uni air filter. I run VP110 fuel straight.
I have 14 hours on this setup, and the quad runs amazing, except the idle stays high for a little bit after I rev it. This has been going on since April.
Tonight I decided to diagnose the problem. There are no air leaks, I installed a brand new throttle cable, and made sure the cable was adjusted properly. Still my idle stays high after I rev it.
Logic would say I'm running lean. Here's where things get interesting, when I closed my air fuel screw my quad stayed running and didn't miss a beat. When I pressed in my hot start lever the quad rev'd up slightly. This led me to believe I'm running rich. Dropped my pilot to a 42 and a 40, still rich and I can still close the air fuel screw without stalling the quad. Dropped my main jet to a 158 and then a 152 still rich (closed a/f screw still runs) and the quad still runs fine, and the idle still stays high after I rev it. Leaned out my HRC needle, no change.
Tomorrow I am pulling my carb apart and cleaning everything. Can anyone think of anything that could cause my idle to stay high after I rev it, and also make it seem like I'm rich? I'm guessing there's a clog somewhere maybe.
And yes the plate on my slide is facing the right direction.
Any help would be great. Thanks
I have 14 hours on this setup, and the quad runs amazing, except the idle stays high for a little bit after I rev it. This has been going on since April.
Tonight I decided to diagnose the problem. There are no air leaks, I installed a brand new throttle cable, and made sure the cable was adjusted properly. Still my idle stays high after I rev it.
Logic would say I'm running lean. Here's where things get interesting, when I closed my air fuel screw my quad stayed running and didn't miss a beat. When I pressed in my hot start lever the quad rev'd up slightly. This led me to believe I'm running rich. Dropped my pilot to a 42 and a 40, still rich and I can still close the air fuel screw without stalling the quad. Dropped my main jet to a 158 and then a 152 still rich (closed a/f screw still runs) and the quad still runs fine, and the idle still stays high after I rev it. Leaned out my HRC needle, no change.
Tomorrow I am pulling my carb apart and cleaning everything. Can anyone think of anything that could cause my idle to stay high after I rev it, and also make it seem like I'm rich? I'm guessing there's a clog somewhere maybe.
And yes the plate on my slide is facing the right direction.
Any help would be great. Thanks