Hi all, i dont come on here often except to help my friend with his mc21 nsr250.

Awhile ago he put it away after a ride and had trouble starting it the next morning.
We had a good look over it today but werent able to pin point the issue, heres what it is doing:
http://www.youtube.com/watch?v=b1iDz0SyPgc

Its also running really badly, really sluggish throttle and back firing on both cylinders.

Ive pulled the carbs apart and cleaned them up, replaced rectifier, tried a different battery and cleaned all of the coil connections.

Im starting to think there is an issue with the ecu or stator, can anyone point me in the right direction?

Check and clean all the earth/ground points.

Did you replace the reg/rec with a new one, or a used one? That's often quite symptomatic of a duff unit.

It's highly unlikely a PGM problem. The CDI side is very robust; it's only the RC side that's a little fragile, if the power valves aren't maintained properly.

I did however have a failing stator on my MC21 many years ago, and that did cause a similar issue. I would pull the flywheel off and check for a short circuit in one of the windings.
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Andy.
NSR-WORLD.COM

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Thanks for the reply.

I cleaned up the earth ground by the coils, i need to check the wiring diagram to see where/if there are more.
Brand new honda reg/rec.

I will take the stator cover off in the weekend and check them out, thanks for the help.