That section could well be included in the CRM run if requested along with a nice wide ford.
Yes I do run a fan but it is a small computer one.
I gave the bike a good pressure hosing before stripping it down but I noticed the rad fins were still solid with muck.
A correction the spark plug is a BR8EG not EV

I've now had the head and barrel off and all seems well, rebuilt it and had a run down test.
Guess I have been lucky or I have missed something else.

Eddie Evans wrote:That section could well be included in the CRM run if requested along with a nice wide ford.
Yes I do run a fan but it is a small computer one.
I gave the bike a good pressure hosing before stripping it down but I noticed the rad fins were still solid with muck.
A correction the spark plug is a BR8EG not EV

I've now had the head and barrel off and all seems well, rebuilt it and had a run down test.
Guess I have been lucky or I have missed something else.

Did it get hot enough to bring on high temp warning lamp?
Yes, i only run an 80mm computer fan [ continuous] and I've had no problems.
would you say that, that was the hardest the bike had worked since the previous rebuild?
Mike

No Mike it has worked harder before and after this incident without any problem.
I didn't notice the red light on but that doesn't mean that it wasn't on.
The temp light did come on on a long slow climb in the dark but the light also came on another CRM that was on the ride
I suspect that if I had let the engine idle all would have been well. The barrel would not have lost as much heat and contracted around the hot piston.

Eddie Evans wrote:No Mike it has worked harder before and after this incident without any problem.
I didn't notice the red light on but that doesn't mean that it wasn't on.
The temp light did come on on a long slow climb in the dark but the light also came on another CRM that was on the ride
I suspect that if I had let the engine idle all would have been well. The barrel would not have lost as much heat and contracted around the hot piston.

OK, yes that seems a fair analysis of the problem, which is why as you said , no damage was found.
This probably underscores the value of [water cooling ] which keeps the hot bits cold , but as important the cooler bits hot, thus evening out the engines overall temperature.
Thanks for flagging that up Eddie, as you say , perhaps the best course of action is let the engine run a while after a good soaking to allow the general temperature to be acquired again, before stopping the engine
Mike