My 01 YZ426F and jetting

Yes, I already did a search and I can't really find anything solid to go off of.

Have a 01 yz426f with a fmf powercore 4, I run a 50/50 mix of 101 octane race gas and 91 pump gas. The bike has no air box lid and I throw a new plug and oil in regularlly. The only reason I run that fuel mix is because that is what the bike likes most, I tried all different fuels/mixes and that was best. Carb settings are stock to my knowledge and I figured I would ask the pro's here before I started messin around with it.

The bike runs good, can be difficult to start sometime and I do know how to start it. The problem I am trying to fix is that at idle when I give it a twist it seems to just fall flat on its face. I don't crack it all the way, just maybe 1/4 give or take and it just dies. This really becomes a problem when we are trail ridding, cause I am constantly on and off the throttle. It won't do it all the time, and is even worse in neutral standing still. After I am going and start cookin through the gears it runs like all hell, but I am not always "flying".

I haven't done anyting to the wires (grey wire mod) or any other quick mods.

elevation +/- 575 Lockport, Illinois

Any and all ideas, Thanks

seems as though people on this forum aren't interested in helping out with the newbies...

I would say do a search for the GB mod and get the accelerator pump dialed in, that will probably help a bunch. How about the fuel screw - have you played with it lately? Sometimes a little adjusting on it will help your type of problem. You may even need to clean the carb - if the pilot jet is plugged it can make for hard starting and bad off-idle response.

Hey, good idea, Duhhhhh. Clean the carb. Now why didn't i think of that. The bike is always clean, but i just forgot to clean the inside!!!

Boysen accelerator pump cover? If your problem is crack throttle bogging, a lot of people like the boysen cover. I have it. They (Boysen) have a money back guarantee that they really mean. My problem was stalling. I would stall it hot in the middle of a fast run with the boys, never cold. It would re-light and idle fine, then when I cracked the throttle to take off again, it would stall again. This is an accelerator pump problem. Good luck.

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