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2009 big bear 250 no spark help?

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guys, I created this account to seek some help, I am a master certified car mechanic, and am working on my friends 2009 yamaha big bear 250 2wd. It has a no spark/ intermmitant spark issue. I have purchased the yamaha repair manual pdf. Now my problem is that there seems to be a discrepancy between what the repair manual says, and what wire colors actually are on the vehicle. I have called yamaha, and they were no help. Also the dealer where she bought the 4 wheeler was bought out last year, and the new dealer has no repair records. ok, so down to business. I found a bad spark plug cap, and replaced it, but I am still not getting a pulse to the primary side of the coil. According the manual the next step is to check the pickup coil resistance, and then the source coil resistance. ( see picture) the pickup coil is the w/g, and w/r wire, with a resistance of 189-231 ohms (these wires appear to be correct) and the source coil is Br(own) and B(lack) i think. with a resistance of 270-230. The problem i am running into is the source coil color of wires are not matching what is in the repair manual, so i am not sure what i am testing. I ended up following the wires all the way into the stator housing. The w/g, and w/r wires go to what appear to be a pickup coil (see picture). in total there are 7 wires, coming from the stator housing, the w/g,w/r which i beleive are the pickup coil wires, 3 white wires, which I think are the 3 phase generator wires going to the rectifier, and lastly there is white/blue wire, and a solid red wire which I think should be the source coil (i do not know what a source coild is or does exactly nor what one is supposed to look like), but they also trace back to the stator windings, but are seperate from the 3 whites (see pictures). Also after the connector (see picture, the white blue wire now becomes a w/g wire that splices together with the other white green wire, then these wires now totalling 3, w/g, w/r, and red go into the cid. When I test the wires, the resistance to the pickup coil(?) is way high, and the resistance to the source coil(?) is about 0 ohms. Can anyone confirm, or steer me in the right direction for diagnosing this thing? I really appreciate your help. the only other question i have is that I'm not sure i could truly confirm that this is a 2009 model. It says it is on the emissions sticker, and the vin on the title says it is, but no where on the frame could I actually find a vin stamped, any help with this is also appreciated.







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Welcome to QUADCRAZY. Maybe it's not a 2009. You could check the manual for older big bears below but its for a 400 and see if there is any info in there that's closer. Or check the other yamaha manuals available in the downloads section for wiring schematics https://www.quadcrazy.com/files/category/3-yamaha-atv/

There really should be a vin stamped somewhere unless this ATV was repaired/modified or even stolen at one point where they would remove it.


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AJmboy, having looked at that repair manual, the wire colors match. I'll recheck the resistance values, but they look close iirc. thanks for posting that, i'll check back once I check again.



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just, checked yes, if this helps anyone else, great, or its very possible, that this model was not really a 2009, or that there were some major modifications to it. Anyhow AJMboy, thanks for the help, if anyone wants to check, at page 9-9 of the repair manual you posted, the wires match exactly with what is on this particular atv. The w/g, and w/r red wire lead to the pickup coil, and the restistance was 525 ohms, right in spec. And the w/bl and red wire led to the charging/rotor rotation direction detection coil, and resistance was just above .1 ohm, also right in spec....using this i can now condemn the cdi.

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