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Bike cut out on holeshot, starts on the stand then dies when ridden

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Leaving the track right now, had the holeshot in my second moto but bike quit on the straight right after.

-- came up the start straight, bike went from wheeling to bogging out. Didn't lock up just slowed to a stop

--Took the plug out, put in new one started first kick. I shut it off. Put everything back on. --Rode around the pits but as soon as I idle then open the throttle again it just goes Bluuubb Bluuubb...

--Took plug out no spark, both plugs are perfect.

--Another note, when the bike was on the stand I revved it, it would idle high for about 5 seconds then go back to a little lower then normal idle

Track worker said it might be stator cus as it heats up it cuts out

Any ideas are appreciated thanks!

ONE MORE IMPORTANT NOTE:

I had the grounding bolt fall out during break in in April got a used CDI off of moto-recyclers.net for $75, because the bike died and wouldn't start, and everything I checked (not the stator or magneto) checked out okay.. Got the new CDI, second kick and its been great ever since

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sounds like a cdi to me. same thing happened. If it wont start try heating up the cdi and then starting. Worked everytime for me so had to get a new cdi. could also be stator

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What do you mean by heating up the CDI? What exactly does it achieve??

Also if I get a new CDI it will be the 3rd different CDI on the bike in 1 year,

-- 1st one I'm assuming shorted out because of no ground (bolt fell out as stated in first post)

-- this time it went from flawless to not even working?? I understand i bought this CDI used but CDIs just can't go that often

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What bike is it? If it has a carb then you can check to see if the main jet had come loose and fallen out. Were the plugs fowled when you removed them?

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It's an 09, plugs were both fine but I figured to put a new one in since I already took the old one out..

The carb does have a "on the fly fuel screw" that we checked we reset it and estimated to 2 -2 1/2 turns, because the track worker that was next to me when it died said it sounded like it was a gas issue.

But once on the stand I felt like it wasnt firing correctly, Or the idle was off because as I stated before after I have it gas it idle really high for a few seconds then really low. Also when held wide open it has a bit of a studder in the BRAAAAAAAAAAA sounds like it kind of a coughs,

we couldn't fully determine if it had a spark during the day time that's why I'm guessing electrical, but now that I'm explaining this more maybe its time to look at the carb, (and re jet it while I'm at it)

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check to make sure the main jet isn't laying in the bottom of the bowl .. 

this happened to a 2 t i had, ran fine on the pilot .. twist the throttle .. boooooogggg. 

might not be your issue but and easy thing to check to eliminate it. lot easier than messing with electrics ... only to find out later ...

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Every bike that had a bad cdi that i had you could heat up the cdi with a heat gun for about a minute or so and it would start right up and run fine.

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If you are going through CDI boxes there has to be another issue causing them to go. I had pretty much the exact same problem with my 07 KX250F and it was the stator. Bike would work fine but when the bike got to opperating temperature the stator would fail. I have seen this a few times with friends bikes also.

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If you are going through CDI boxes there has to be another issue causing them to go. I had pretty much the exact same problem with my 07 KX250F and it was the stator. Bike would work fine but when the bike got to opperating temperature the stator would fail. I have seen this a few times with friends bikes also.

That's exactly what the track worker who helped me out said. I'm going to check the carb first when I get the chance and I'll come back here and tell you what's going on. It's either the carb or stator.

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No haven't taken it apart yet. I have a 125 to ride in the mean time, ill probably check the carb Friday or Saturday and check in back here,

Im actually waiting on a fuel hose to get here because I somehow managed to tear mine while removing the gas tank at the track . So obviously the bikes still dirty and cant be power washed until that's sealed up. So once the bike is clean Ill start opening some stuff up and getting to the bottom of it

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Alright guys I opened up the float bowl, nothing there except some gunk I need to clean off in my spare time....

So this would bring us to door number 2, stator.. How would I check that, as in is there a visual way once I take the timing cover or whatever it's called off??

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you need to find the specs and test with an ohm meter.

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Okay checked out the stator coil resistance. Checks out perfect

BK/R lead R/W lead = 33.3 ohms (27.2 ~ 40.8 is the correct reading range)

W lead Y lead = 2.4~2.5 ohms (1.76 ~ 2.64 is the correct reading range)

Where to now??

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Try heating up Cdi with heat gun not too hot but just till it gets warm on inside for about 30 seconds and try again...if it starts and runs fine then probably that. It worked for me every time

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Any more ideas of what to check?

Friend said maybe its bad gas because befor the race I stopped at a gas station to get some gas and I filled up before that moto? Maybe clogged something?

Edited by Jrc579

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If there was junk in your float bowl then you may have already found the issue. Your float bowl should be clean. I would pull the jets out and clean them, clean the float bowl, drain out your gas, and get some good gas. It probably wouldn't hurt to put a fuel filter on the fuel line to keep anything that may still be in the tank out of the carb.

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