Engine flutter after a very long ride

[owain]

I've just rode from north to south wales, riding pretty much continuously for 7-8hrs. Bike was running great the whole way until the last 8 miles from the campsite. It's difficult to describe but engine fluttered a few times and wasn't firing correctly. I suspect maybe the mag? do they misbehave when hot?

[Greybeard]

Is it possible that the fuel was vaporising? I had that problem recently while I was driving in traffic on one of the very hot days we've been having in the UK .

[owain]

A heater insulation washer?  . No I just have a paper gasket/drip tray/ paper gasket/ carb set-up on my A10.

I'm hoping that vaporising in the carb is the issue as I still need to get back to North Wales 

[owain]

Issue has worsened with the A10. Bike is now "shunting" when under heavy load (going uphill) and anything over 3/4 throttle. Started to occue 2hrs into riding today. Could there be any other causes I could look at?

Seems to run fine at low speeds. In Swansea now. Trying to limp it to a friends driveway in Cardiff :/.

Seems strange that'd perform well for hours yesterday only to misbehave today.

[Triton Thrasher]

Check plugs, then points.