magg wrote:Just so I understand, when the engine is cold you can rev it without any problem and it rides ok too. Then once the engine is hot, the problem appears. How long between running ok and heating up before the problem, one minute, 5 minutes, what reading on the temperature gauge?

No, it will rev fine below 8000 rpm hot or cold. Anything above and it bogs down. I can't explain it.

I am waiting to borrow Drunkn Monkeys spare cdi that he has offered. I am really hoping it is that.

I had a similar problem on a VFR800 once and it turned out to be thermal instability in the alternator windings. They worked at idle and for the first 5 mins or so, but once warmed up, the winding insulation broke down enough that the alternator didn't provide enough juice to charge the battery. Misfires and general misbehaviour increased from the point you were just too far away to push it home until it inevitably died a bit further down the road.


I'd check your charging voltage from cold and again once warmed up to eliminate this potential cause from your enquiries.

squaredoffagain wrote:I had a similar problem on a VFR800 once and it turned out to be thermal instability in the alternator windings. They worked at idle and for the first 5 mins or so, but once warmed up, the winding insulation broke down enough that the alternator didn't provide enough juice to charge the battery. Misfires and general misbehaviour increased from the point you were just too far away to push it home until it inevitably died a bit further down the road.


I'd check your charging voltage from cold and again once warmed up to eliminate this potential cause from your enquiries.

I have had everything checked. All ok. Battery charges no problem.

any luck yet?

I borrowed Drnkn Monkeys spare CDI and it worked a treat. I'd like to say what a splendid chap he is and to publicly thank him.
Hopefully see you at the rally in weeks time.

Cheers
Andy