Bought a mph speedo of ebay, after fitting it my nc30 it starts and runs fine upto about 5500/6000 rpm then starts miss firing , i noticed when fitting it that the mph speedo has a 3 pin connector less than kmh one .

Ian

You are getting the speedo disconnected misfire. You need to either buy an M Max box, or speedo deristrictor or solder a resistor across the terminals to fool the CDI into thinking the speedo is there.

At the min it will be not seeing the speedo and the 5.5k revs cutout drops it to 2 cyl

So, DIY method using a resistor - takes an hour or so and 50p..or buy a deristrictor box for approx 10-20 wuid, p[lug it in and all good without changing anything on your loom.

You wouldn't happen to know what size of resistor and which wires to bridge it across

Don't quote me on this but IIRC it's a 2.2K resistor.

Thanks for your help, bought a resistor mod kit from leopard pagan, job done and bike back on road, i can actually see what speed i'm doing now

haha good stuff!