2003 honda crf450 won't run right

I have a 2003 Honda CRF450 and I have had it in the shop to many times and the people never fix the problem. What is happening is when I am riding the bike it will bogg out when i twist the throttle just a little bit fast not even snapping the throttle. This makes the bike shut off at low speeds or when I am trying to climb a hill it will bogg out. I have only been able to compete in one race this whole season which has really disappointed me. I think it is due to jetting because i have had my valves checked at least 5 times in the past 2 months and they say it is fine. Z&M cycles says with my Big Gun full exhaust I should still be running stck jetting I do not know if this is correct or not. I submitted a question to big gun exhausts and they told me to run a 178 over a stock 170 main jet. but I think the problem is that the bike is running to rich. If anyone has any suggestions they would be greatly appreciated.

is the jetting stock now?

is the motor stock?trail tech flywheel?

the motor is stock accept for a big gun full exhaust system and it still has stock jetting

has any actually looked to see if the accelerator pump squirts?

does the bike idle well?

i dont know what an accelerator pump is but if you could tell me how to check the problem and how to fix it Then i can do it

you need to remove the carb from the bike.once its out operate the throttle with the carb pointing away from you.watch for the squirt.

has this bike ever run right?did someone work on the carb then start with this problem?

when i first bought the bike it ran fine but when i guess the hot weather came around it started to have the problem. I originally took the bike to Z&M cycles to get fixed for this problem. they fixed it but after one ride it was back to doing the same thing again. What they said they did to correcct the problem was adjust the air screw out a 1/4 turn. but after one ride it did the same thing all over again I tried to adjust the air screw out farther but it made no difference.

its a fuel screw.if the bike acts up when its hotter its rich.in is leaner on the fuel screw.you were making it richer.

so how would i adjust it to make it correct and thank you for your time helping me

set the fuel screw at 2 turns out.with the bike warm and ildeing turn the fuel in till the biek dies or the idle drops/misses.then go back out just till the ilde peaks/smooths.

this should happen between .5 and 2.5 turns.

less than .5 you need a smaller pilot jet.more than 2.5 you need a bigger pilot jet.

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