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400ex87
04-10-2006, 09:25 PM
what does it mean when the engine pops when the revs are slowing down? i am guessing lean? i am jetting my ktm 525 hybrid and got the fcr39cr carb..any suggestions?

smitht316
04-10-2006, 10:24 PM
what do you mean by when the revs are slowing down.... like when you are just coasting at higher rpms???

GPracer2500
04-10-2006, 10:37 PM
Popping under deceleration on a closed throttle is normally a sign of a lean pilot circuit. Being too rich can also create a noise under decel but it's more of a wet "blab" sound vs. a sharp "pop" sound.

400ex87
04-11-2006, 07:52 AM
no..its a sharp pop sound, and what i mean it when i am idling, and i start to rev it, then i rev it real high, when i release the throttle and the rpms decelerate it will pop usually once before returning to an idle.

GPracer2500
04-11-2006, 10:11 AM
Originally posted by 400ex87
no..its a sharp pop sound, and what i mean it when i am idling, and i start to rev it, then i rev it real high, when i release the throttle and the rpms decelerate it will pop usually once before returning to an idle.

lean pilot circuit

zeppelin
04-11-2006, 04:40 PM
Originally posted by GPracer2500
lean pilot circuit actualy it is usualy the fuel screw ;)

GPracer2500
04-11-2006, 05:25 PM
Originally posted by zeppelin
actualy it is usualy the fuel screw ;)

The fuel screw is part of the pilot circuit. ;) ;)

zeppelin
04-11-2006, 06:34 PM
oh, lol, i thought you were just refering to the pilot jet, my bad.

400ex87
04-11-2006, 06:47 PM
my main jet was a 165! i put a 175 in there are it pretty much solved it, airscrew is 2.5 turns out, i am gunna make it 2 3/4 out. Pilot was a 50.

GPracer2500
04-11-2006, 06:53 PM
Originally posted by zeppelin
oh, lol, i thought you were just refering to the pilot jet, my bad.

No worries!!:D