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2004 yz250f wont start

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Any suggestions? :applause: I bought a new spark plug, and that didnt work, and it wont even spark. I unhooked the killswitch in case it was jammed, and it still didnt do anything. Is there anything that could be wrong with the cdi unit? I was riding earlier today and i stopped and shut the bike off, it was running fine, and then i couldnt get it to start again, until i bumb started it, and then when i stopped, it died. And i was unable to start it, and had to push it half a mile, that sucked.:applause:

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To me it sounds like the valves got tight on you. or most likely zeroed totally, b/c you said it won't start at all now.

I would pull off the valve cover, set to TDC and check all clearances, get the correct new shims that you need and install them... :applause: I saw a tutorial on here about checking the YZF valves. I think it was in the technical section.

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Well, the spark plug wont even spark, and i dont think that has anything to do with the valves.

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Hey at least you got to ride for more than 10 minutes, and didnt have to push your bike half a mile.:applause:

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hey at least i can ride a 250. OHHH:p haha. WELL I NEED HELP WITH MY BIKE. im thinking about buying another cdi box.

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If you can kick it over and the compression seems good then check your kill switch and wires. I've seen that happen more than once.

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So you do have spark and all that right? You dont want to got out and buy a $400 CDI Box if you dont have to..... Just get it fixed in time for Hannegan.

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i need it fixed for tehuya to. There is absolutely NO spark in the plug. I priced some cdi units on ebay, and they were about $50.

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hey at least i can ride a 250. OHHH:p haha. WELL I NEED HELP WITH MY BIKE. im thinking about buying another cdi box.

Why the heck would you buy the most expensive part when you don't even know what it is?????

There is even a section in the service manual how to test the CDI box. All the CDI really does is timing, nothing else really...

Pull the plug out, hold the threads to some metal and have someone kickstart it. You should have a good strong spark. No spark, then you need to start testing your coil.

How old is the gasoline? Is the carb clean? Have you even tried these cheap posibilities?

Starting with the most expensive part is the WORST way to diagnose a problem. I learned the hard way when a tranny temp gauge that I bought for my old Tacoma was registering 230degrees. After flushing the tranny, changing the filter and fluid again and scratching my head, it turned out to be a 10 cent nut that came loose on the gauge...

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gas is only 2 days old, im gonna check the carb later tonight. My dads friend is a like a dirtbike expert and i think he is coming over sometime this week. Im pretty sure the problem is electrical though, but i could be wrong.:applause:

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Looking at your other thread, you started you had no spark when you put the plug on metal. Was this unpainted, clean metal?

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everything is clean and i put it on like 5 different things like header pipe, frame, motor mounts, and other parts made of metal

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Im not a troll I was just giving him some of his own medicine because a while ago I could never get my bike started and he would always say its cause its a Honda. Sorry if I offended anybody.

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You are trolling because you are trying to stir up trouble (ie: saying Yamaha is crap in a Yamaha forum)

I would start checking the carb and gas and checking your cdi as outlined in the manual.

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yea im going to have my dads friend check all of the electrical tomorrow or the next day. I dont have all the right tools yet

.

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