Dave, your right that it doesnt do it on initial start up, only when the exhaust has started to get warm. Your probably right with the "pinking" too, its always just a "click click" when i floor it at low revs, I know my mongoose creaks when I reverse (great design that they are with no flexi section ) so its probably just that. I will be running some more tests 2nite to try and listen some more.

My concern at the moment is that when I took her out last night after a big bang I got at 5K when (I assume) the spark blew out again it was then missing once or twice off boost at light throttle - could the misfire have upset the plugs or something?.

What does everyone think of the GRP A coil idea?, would this be a good move?

Cheers

Stu