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2004 KTM 450 EXC Jetting Help

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I have a 2004 KTM 450 EXC in Allentown PA area approximately 350ft elevation above sea level with temperature in the 60's to 70's....but I also ride in 80's.

I'm running a brand new factory KTM header pipe with original stock KTM muffler and airbox. Also running brand new pre-oiled foam filter with pantyhose style filterskin also lightly oiled. I don't see extensive blueing of the pipe yet..or any leaks that I'm aware of.

I am running a JD Jetting kit with the BLUE needle in the #3 clip position and a 172 main jet. The carb has been thoroughly cleaned.

The issue that I'm having is when I blip the throttle QUICKLY from idle, the engine cuts out and even stalls. The motor will BUILD rpm's great, and moderately quickly. But when I blip the throttle fast from idle to say half throttle, the engine cuts.

I thoroughly warmed up the bike until the factory (option) fan kicked on and the condition remained the same. I will admit I have not FULLY tested the bike riding etc but I know this condition is not correct and should be able to be fixed.

After I tore the carb apart for the second time to make sure everything was clean etc, the carb is peeing gas all over my garage floor so the float is sticking a bit. But the condition has not changed. The float was not stuck in my previous testing and the condition still existed. Also, I have the pump speed o-ring from the JD kit off right now but that didn't seem to change anything either.

The carb has a Boyesen QuickShot (I or II, not sure) installed and MSR fuel screw at approx. 1-1/2 turns out. I did adjust the fuel screw and it may vary 1/4 turn from there; I can double check. This improved the problem but did not cure it.

Hope this wasn't too much background...Any advice?!

Thanks ThumperTalkers,


Edited by StarRaVenRiDeR

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Your post is very hard to read with all the colors.

You have a bog, but you do not know if you have one when the bike is ridden because you have not done so yet. Right?

What the bike does in your garage means nothing. You have to ride the bike, in a normal fashion. Any bike can be forced to bog. Test ride the bike, riding normal. Do not sit there, engine idling and nail the throttle WO and expect it to run. Ride it normally. If you still have a problem with a bog, we can take it from there.

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