Good morning gents!

I own a beautiful NSR250 MC21.

I have the following issue that just developed by itsellf:

Bike starts very easy. Idle is consistent. When in neutral, it revs up to 10k revs nicely. Engaging 1st gear still no problem.

As soon as I start releasing the clutch to pull away it starts backfiring...mostly through the left exhaust.

If you then slide the clutch I get it up to about 9k revs, backfiring and stuttering all the way.

I.e as soon as there is load on the engine the symptoms start.

Any ideas would be greatfully accepted. I am running 30 to 1 premix, plug gaps are set, airbox is on although not 100% sealed around the inlet rubber.

Cheers from a HOT Cape Town!

I would suggest checking the coil connections. If loose, this can cause arcing and backfiring. Make sure the blades are clean and fit snuggly, maybe pinching lightly with needle nose pliers if need be.
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-Jim
'93 MC21