Lost spark

[mdude]

Went for a good drive yesterday, in cloudy chilled and moist autumn weather (not rain).

 

Machine started and went well for 5-7 minutes, then stalled in rush traffic. When started again, the right cylinder wouldnt come out to play.

 

It spluttered into life now and again. After a cooling break I cleaned the plug and adjusted the gap (on the plug, not my own gap...). the plug was seriously soiled, with a lot of coal on it.

 

Then the bike started perfectly, went well again for about fifteen minutes. When dropping down below 3000 rpm in tight traffic, the cylinder died again. It woke up above 4000 rpms, which was interesting when 60 or more hps arrived quite suddenly. 2 kms from home it died for good, and I limped home.

 

Of course I'll be changing the plugs. But is there anything else I should check? To me, this seems like something more than just the plug?

Someone mentioned that I should change to slightly "hotter" plugs, is that a good idea?

 

Where I live, in the middle of the city, its inevitable that I get stuck in traffic in the start and end of each trip. Low rpms and idling for about fifteen mins...

Anything I could do to adapt the bike to this?

[callison]

Check that the plug wire hasn't been snagged at the spark plug cap. Also check under the tank at the coil and make sure the spark plug wire hasn't pulled back there as well. Honestly, I've had both happen. Especially after doing some form of maintenance where things might get disturbed. Sometimes its a faulty spark plug where the insulator is cracked or separated from the electrode. These are all cheap and easy things to check, so that's where you start first.