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Need some input....

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I posted this in the KX450F forum also. Thought I might find some lurkers here. :smashpc:

I need some help. 2007 KX450F.

Out riding and after doing a high speed section when I came into the turn bike stalled fired right back up but when it gets to mid throttle it cuts out and missses and stalls when coming into a corner.

Cleaned carburator checked valve clearance new improvement.

Replaced spark plug and that eliminated the stalling in the corner but still have the mid throttle cutting out. (Bike runs perfectly everywhere else just at a constant throttle)

Cleaned carb again no improvement.

Replaced coil no improvement

Took kill switch completely off bike. No improvement

Unpluged all connectors and cleaned them with contact cleaner. No Improvement.

Cleaned carb again and replaced power valve no improvement

Moved the needle down one clip setting and that fixed 95% of the problem but of course the bike is running hot.

Read some of the older posts and had several suggestions about replaceing the jets so I ordered all new jets with the team green recomendations and a new top end.

Installed new piston and rechecked valves. Installed new jets in carb rechecked float height setting. And put needle back to third clip position.

Still have the same cutting out at a constant throttle.

I am usually the one that everyone calls to fix their bikes so this has been extremelly frustrating. I have spent hours on here reading pages over the last month trying to find the issue with this so if you guys have any suggesting I am willing to try it...

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I posted this in the KX450F forum also. Thought I might find some lurkers here. :smashpc:

I need some help. 2007 KX450F.

Out riding and after doing a high speed section when I came into the turn bike stalled fired right back up but when it gets to mid throttle it cuts out and missses and stalls when coming into a corner.

Cleaned carburator checked valve clearance new improvement.

Replaced spark plug and that eliminated the stalling in the corner but still have the mid throttle cutting out. (Bike runs perfectly everywhere else just at a constant throttle)

Cleaned carb again no improvement.

Replaced coil no improvement

Took kill switch completely off bike. No improvement

Unpluged all connectors and cleaned them with contact cleaner. No Improvement.

Cleaned carb again and replaced power valve no improvement

WHAT ARE YOU CALLING A POWER VALVE? NO SUCH THING ON A FOUR STROKE MOTOR.....

Moved the needle down one clip setting and that fixed 95% of the problem but of course the bike is running hot.

Read some of the older posts and had several suggestions about replaceing the jets so I ordered all new jets with the team green recomendations and a new top end.

Installed new piston and rechecked valves. Installed new jets in carb rechecked float height setting. And put needle back to third clip position.

Still have the same cutting out at a constant throttle.

I am usually the one that everyone calls to fix their bikes so this has been extremelly frustrating. I have spent hours on here reading pages over the last month trying to find the issue with this so if you guys have any suggesting I am willing to try it...

It really doesn't matter what RPM it occurs in, it's what THROTTLE OPENING the problem happens.

You haven't said what rpm/throttle position/engine braking that you are in when it occurs,.

Sounds like your Needle Jet is ovalized (the thing the jet needle drops into).

Have you confirmed proper operation and/or seal of:

- hot start plunger

- choke plunger

- slide plate and seal

- apump nozzle creating perfect arcing squirt for 1 second, directly into the intake of the head

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Was thinking of something else when I said power valve I meant the accelerator pump.

I also replaced the slide plate and the seal the same time I replaced the jets.

It cuts out between 1//4 throttle and wide open and only when its held at a constant position never on deceleration or acceleration and when it cuts out you can accelerate and it cleans right up.

I double checked both the hot start and the choke tonight got proper opperation...

Will have to look first thing in the morning on the needle jet ovalizing anything specific I should be looking for?

Thanks For Helping !!!

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Checked for that any kind of wear or ovalization where the needle jet goes and all looks good.

Trying to get ahold of another bike today to do some part swapping.

Also going to check valve clearance, all passage ways in carb and put a new plug in bike again and see if I possibly overlooked something.:smashpc:

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Have you looked for shorting/arcing wires, bad plug high-tension lead or cap, bad coil ground?

You say 1/4 to full throttle: that's too wide a description.

Find a hill, try going up with fixed throttle positions, slightly more each time, until you find where it occurs. If it does not occur based on throttle position, but by load or rpm, it's not the carb.

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Today I swapped carbs with another bike and cdi boxes no change. TearPping back into the top end hoping that I find what ever I'm over looking. It cuts out from a quarter throttle and up.

I know thats a pretty broad area but anywhere in that range once you stop rolling the throttle on and hold it constant it starts cutting out or hesitating.

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Have also replaced the wiring harness since my last post in here. Hoping that maybe someone has some new ideas...

Thanks

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Replaced the coil, wire, boot and plug.

Relaced the complete wiring harness

Removed the kill switch completly off the bike.

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