[Darren69]

Originally Posted by Mr Gazza

Eureka!
It was screaming pickup to me, but it doesn't help when people tell you that pickups either work or don't work.
So what we have learned here is that not only can a pickup failure manifest when it gets above a certain temperature, but also when engine revolutions exceed a very low threshold.
This proves that they can work just a little bit, but not enough!

I'm delighted you've cracked it and without mauling the carbs too.
You only ever find what you're looking for in the last place you look unless you insist on continuing to look after you've found it..

I very nearly commented on the pickup issue as from my experience that wasn't entirely true. Coils can behave differently or oddly if there is internal corrosion and can break down under certain conditions, as you have found. Same for HT coils or coil sticks as I found. So that was unhelpful comments from Electrex. Glad you got it sorted in time for a few weeks of fun.