It sounds daft but have you checked the obvious stuff.

Tyres at correct pressure and not flat.
Brakes not binding
no air leaks on carb (is the lid screwed down etc)
Good clean Air filter in?
Nothing loose or about to fall off etc
good fuel in the tank?

Have you done anything to it since it went up the hills well?

In it tonight?

Max...I dont get that photo

Matt yup i'm in it tonight but it will be dark haven't touched it (i don't tend to) so maybe ill get someone to have a looky before france

A bit of background info. The engine in question has had, in its recent past, its heads re-torqued and valve clearances set and runs a 123 ignition which is also correctly set. Compression is good, carb nuts all tight (or at least they were) and no obvious air leaks (inlet manifold bolts all tight etc). All this was a fair few thousand miles ago by now though so things could have changed!

Betty has displayed the symptoms of overheating in the past though, it sounds like it has maybe got a bit too warm again for some reason?

Might be worth checking the oil cooler for gunk buildup and iirc the engine has always had a fairly sizable 'flat spot' too so trying a different carb might improve things.

Its a gs 4 cylinder engine.

Yeah lets have a gander and see if anything has obviously fallen off/gone wrong. Oil cooler might be clagged up or the breather might be shot.

might just be nothing to worry about like crap fuel. Stick some super unleaded in it and see what happens.

Haha wanna come fix it seems you know the most about it

Lou

I was always told if you don't ask you don't get