No spark on XR 250 R

My 1991 250 had been running very bad this spring, i have made several changes to the jetting to fix it, but i think it may have been an electrical problem. I have a new plug and am not getting any spark. What has caused my spark to stop?

Check the simple stuff first. Make sure the spark plug boot is firmly affixed to the end of the coil lead. You could replace the resistor in the plug boot with a copper slug to rule out it being bad.

Check the coils ground wire/point for condition, then trace it's other wire back to the CDI and check connector conditions. Next, check the ignition leads coming off the stator. If all this is ok, I'd swap out the coil with a known good one to see if the coil itself is shot.

Check the Kill Switch, better yet get a new one.

I spent $$$.$$ trying to chase down a problem that seemed to be spark/carb in nature and is turned out to be a $10 kill switch!

its easy to check the ht coil and pick up coil,if you have an electrical tester,both of these components could cause your problems,and ive had both of them go bad on my bike,as well as the cdi,but i dont know a test for the cdi other than trying another one that you know is good,

ht coil,disconect the two wires that are plugged into the coil,remove the plug cap,set your tester to ohms,put one of the testers probes into the end of the ht lead and the other probe to the ground (green) terminal on the coil,the resistance should be between 3.7k ohms and 4.5k ohms,if its not throw it away and get a new one.

pick up coil,disconnect the two wire plug coming from the pick up coil,its the two wires running up the front frame tube,and measure the resistance between the green/white and blue/yellow wires it should be 460-580 ohms if its not it needs replacing,

best of look


Thanks so much, i will be trying this soon. I will let you know what i find.

Well the kill switch issue is a pretty funny story and I would definitely agree, check that stuff first. Also follow the plug wire from it's start to it's origin all while looking for cracks in wiring. Any cracks will ground the charge before it reaches your plug. Electrical, unless tampered with for aftermarket purposes is generally easy to tackle. Look for wear, fatigue, corrosion etc. in your wiring and replace as necessary.

I've got no ohms at the coil, i think that was the problem.

nothing at all?

when my ht coil went down i still had about 2k ohms,

although i did have a spark,it ran really bad and kept breaking down,

you were measuring ohms x 1000 ?

I believe so, i ordered a new coil, that should tell me for sure, i will let you know when i receive it.

Received the new coil today and the bike started on 2 kicks and ran great.

good news :smirk:

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