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08 missing badly from half to full throttle

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Had bike at race meeting yesterday and got just 3 laps in qualifying when problem started. Bike pulls great off bottom but then starts to not rev out and miss and hold back with a strange throaty noise from engine. Today i rebuilt and cleaned carb. carried out all electrical checks as to haynes manual, timing and clearances as should be, Spark pulg also replaced. Wondering if anyone has had any problems with coil packs breaking down or any other faults with same symptoms. :)

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I haven't encountered anything like what your describing, but it sounds like your starving for fuel. Have you checked the screen in the tank? Also, have you checked to see if the timing jumped a tooth. The timing is unlikely, but easy to check. I haven't seen a problem with the coils yet, but I have seen a bad magneto. The bike wouldn't start at all.

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Had bike at race meeting yesterday and got just 3 laps in qualifying when problem started. Bike pulls great off bottom but then starts to not rev out and miss and hold back with a strange throaty noise from engine. Today i rebuilt and cleaned carb. carried out all electrical checks as to haynes manual, timing and clearances as should be, Spark pulg also replaced. Wondering if anyone has had any problems with coil packs breaking down or any other faults with same symptoms. :)
Check the pulse coil. i had sma problem on a yzf like a rev limiter coming in low down.

new coil sorted it.

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Have found problem tonight. The centre had broken out of the right cam bucket on the inlet side. Was informed that this has been a prob on 08,s. The fix is to fit 05 ones as they run heaver inlet springs so the bukets are made stronger.

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No noise in the valve train? I haven't heard anything about the bucket problem.

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No noise from valve train at all. Thats what made me go the root of an electrical fault. Bike would start first kick and idle with no problem. Only after changing all of the electrics from my mates bike I went looking in the head. Very lucky not to have droped a vavle as the spring seat at top was cracked the hole way through at one sideof the retannig seat.

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No noise from valve train at all. Thats what made me go the root of an electrical fault. Bike would start first kick and idle with no problem. Only after changing all of the electrics from my mates bike I went looking in the head. Very lucky not to have droped a vavle as the spring seat at top was cracked the hole way through at one sideof the retannig seat.

I'm not much of a gambling man, but I would have bet the house on some sort of noise in the top end. I've had a broken bucket issue before, but that was a result of a broken valve spring. Glad you found the problem and shared it with us.

Happy trails!

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