I went to go for a ride this morning. Bike started third kick, which is very good for a Honda. Ran fine for the first minute or so, and then started to develop a miss. Another minute elapsed and it cut out on the lower cylinder and backfired (small popping) when rev'd.

I replaced the spark plug and started it again. No difference; this miss was still there. So I replaced the NSR250 coil with a Honda XR coil and started it again. The miss disappeared and I was able to take it for a good 60 km run without any problems.

Now that I'm home, I've gotten the multimeter out and tested them.

The LT on both coils reads 0.3 ohms. The HT side on the NSR coil reads 3,000 ohms while the XR coil reads around the 4,000 ohms (without the plug cap). Maybe this is a intermittent problem that only happens after the coil has warmed up a bit? I'm not sure, any thoughts?

Anybody know where I might find a new coil for the top cylinder (long lead due to 300 conversion)?
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MC21 Honda NSR250. TYGA 300 conversion.