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What would cause a bike to give a Hiccup sound when blasting through gears. I will blast through all gears and when switching for 2-3 and 3-4 the bike will Hiccup right when I shift and give it WOT. Could this be my needle? bottom end response is good. Top-end power is brutal. Am I too lean or to rich? and what circuit?

Not a KDX but KTM guys want even answer my post.

09 250 xc-w
FMF gnarly/turbineCore2
Pilot-38
Main-162
Needle- (stock setting)
52 back sprocket.
Yellow spring in
PV 2.5 turns in from flush

That main looks HUGE!

Jet main with plug chop. What you will find on this site is a guide that will help you learn this yourself, regardless of bike.

What's a hiccup?

I'm guessing the hiccup would be a sputter from rich condition. Drop the main down and try again, or lower the needle by one clip at a time and see if it improves.

A rich condition will usually 4-cycle immediately, then clear out...Most definitely do a plug chop to check your main. We have no idea what MJ the PWK36 in a 250 is going to want (based off KDX data).

ok well i messed up.. 165 main jet!!! that is stock... every thing stock expect for pilot and FMF pipe. It does a pop noise and kinda sputters.

I tried lowering the needle but it seemed to make it worse.

Did you lower the clip or raise the clip(which would actually lower the needle)? If 165 is stock you'll most likely need to be leaning that down....esp in LA.

I raised the clip (lowering the needle). I have it jetted to the factory specs for my elevation and temp. I get confused with that though. When the weather gets hot, I will need to get more air? so I would need to lean out jetting during summer months, and richen up during winter? It has just started to do this. It has been pretty hot down here.

Use your air screw for that.

Indeed...fine tune with the screw. Need to jet your main via plug read. Generally hot=leaner, cold=richer concerning weather, but it's all about air density.

when i had the 162 the power was really soft. i put 165 back in and power is pretty nice except for the stutter, hiccup thingy. wouldnt midrange power be effected by needle get?

generally yes, but make sure you are thinking of throttle position when you say midrange, and not RPM.

well then maybe it is my main... I am always WOT. I never really roll the throttle. I will try just rolling the throttle hard through all the gears and see at what throttle position the noise is coming from.

If you're able to be always at WOT on a 250 I'd say something is wrong with the bike. Most riders are rarely at WOT.