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Old 01-01-2015
LABRADOR Coaster LABRADOR Coaster is offline
DBW Dweller
Join Date: Dec 2014
Posts: 9
YZ250-lost spark, all tests checked out OK...

Good morning gentlemen,

A couple weeks ago I tipped over on my bike a couple times, couldn't,t get her to go, new plug no spark.
since then I have run thru all the diagnostic test shown in the shop manual.

Stop button checks out
Primary coil resistance was 00.3 ohms (acceptable range 0.20-0.30)
Secondary coil. Was 12k ohms (range 9.5-14)
Spark plug cap. was 4.6k ohms (4-6)

Pickup coil resistance was 280ohms (248-370)
Source coil #1 was. 806 ohms (720-1080)
Source coil #2 was. 50 (44-66)

The manual says to replace the CDI unit if all these test are good and run tests again, wondering if there is a way to test the CDI unit.
The bike is a 2007 with low (50) hours. In my shop with low light I can see spark on the plug if I kick real hard. Tried priming her to see if she would fire but nada..all the wiring harness seemed to be in good shape also.
Also...I ordered a secondhand Cdi box from Ebay, coulda swore I saw YZ250 in the list of bikes it fit, next day I noticed that the CDI is for YZF 250 which is a 4 stroke. It looks exactly the same so hoping it will work, what an idiot!!...

Any advice would be appreciated, thanks.

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