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urgreathero

07 yz450f

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i have an 07 yz 450f

ran fine

let it sit for a week but now wont fire, changed spark plug, checked carb and everything seams fine, seams like its getten compression

just wont start

ne ideas?

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I let my YZ450 sit for 2 months while I rode around on my CRF.

I drained the fuel from carb and tank.

Filled her up and no way I could get it started.

Then I opened the carb drain again. closed it. twisted the throttle and hey presto fired right up.

Go figure..

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ya its not carb though everything worken correctly

its got compression

jsut no will to fire,

im about dun wit dese four strokes

next chance i get

ima sell the ****er n got back to 2 strokes

i have nutthen but problems wit this damn thing

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Does it try to start?

My '07 sits for a week or two all the time, I try with the choke then without and it starts up within 5-7 kicks.

It starts way easier than my '05 RM Z450 did, even after adding a JD jet kit and adjust the air screw.

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i had the same problem with my 450 last year when i first broke it in.

get the valve clearence checked out...that seems to be one of the most common things that stop a brand new yami 450 from starting just after break in from my experiences.

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all the shops r backed up for weeks around here

seein how race season just started n all

but i dont think its valves

it has all the compression in the world

just doesnt wanna fire

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When you say does not fire, do you mean it will not start or you are looking at the spark plug and have no spark. If you have no spark then see if you can borrow a coil and CDI box from someone and re-test. These are easy enough to change out. If this does not cure the problem I have seen a few stators fail on YZ-450's so you can check that also. Also do not forget to unplug the kill switch in case it is something that easy.

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nah its not the sp

it has tons of spark

its not getten gas

new plug is clean

so it has to be a carb.

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nah its not the sp

it has tons of spark

its not getten gas

new plug is clean

so it has to be a carb.

I read someone else had a kinked fuel line?

So, no fuel is getting to the carb?

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I read someone else had a kinked fuel line?

So, no fuel is getting to the carb?

oh yea i nvr thought about that good idea

ill check that out aswell

nice one

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I have a 2003 YZ450F, my 2 buddies, they have a 05 & 07 YZ450F, we all have to open the throttle like 2 or 3 times, half way each time, then fell out the compression stroke in the motor, & kick it like a MF...also check everything everyone else said before me...good luck let us know whats going on

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I have a 2003 YZ450F, my 2 buddies, they have a 05 & 07 YZ450F, we all have to open the throttle like 2 or 3 times, half way each time, then fell out the compression stroke in the motor, & kick it like a MF...also check everything everyone else said before me...good luck let us know whats going on

alrigth

i currently have whole bike striped to frame

going over everything to make sure its nothing major

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Your pilot jet is plugged it is one of the jets next to the main pull it out blow air through it and the bike should fire right up.

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yup it was jet i changed it and put it back in and now it leaks gass out of backflow tubes

i think i put bowl on wrong

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the float bowl is now stuck, tap on the bowl an it may free itself.

it was the float hidth i had to bend it down a lil that float tab next to needle

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