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bike died

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I was riding on Sunday when my bike cut out. It was running fine and then all of a sudden spit and sputtered and died and would not restart.

The compression is fine and there is spark. I thought it may have been my valves but all of the clearences are okay. My friend had his flywheel key shear off and the fly wheel spun on the crankshaft throwing the timing way off but that checked out okay.

I'm thinking it's a fuel problem since I have spark. I'm going to pull the carb to see what's going on in there. Maybe the circlip came off the needle or the main fell out.

Anybody have a problem like this or any suggestions on what to look for. Thanks. :thumbsup:

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The only way to test your coil is with an ohmeter. A visual inspection of the spark is not sufficient. Conditions are very different in a running engine than in the air outside. I'm not saying weak spark is necessarily your problem, but just that the visual ispark inspection can throw you off.

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The bike is an 03 crf 450, I didn't state that in the original post. I pulled the plug and kicked the bike. I would get one quick spark every second or third kick, but 75% of the time it was on the third kick. Is this how a fourstroke should fire or should it be more of a steady spark . I'm going to purchase a multimeter and diagnose the electrical system.

Anyone have a clue?

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It should spark every other complete stroke. That's part of what makes a 4 stroke a 4 stroke.

Your 4 strokes are:

Intake (down stroke)

Compression (up stroke)

Power (spark, down stroke)

Exhaust (up stroke)

Intake (down stroke)

Compression (up stroke)

Power (spark, down stroke)

Exhaust (up stroke)

Intake (down stroke)

Compression (up stroke)

Power (spark, down stroke)

Exhaust (up stroke)

Intake (down stroke)

Compression (up stroke)

Power (spark, down stroke)

Exhaust (up stroke)

et.

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If you want pull the head and spray something down the intake and exhaust ports to see for any leakage.....when mine were bent all the clearances were perfect, my timing chain jumped from revving the piss outa the old girl

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