1.9 Aircooled hot seizing

[TeamBonzer]

Hi I have an early 1.9 Aircooled T25. Just restored out and inside and was looking forward to some fun. Problem is that it starts and runs really well at first, but when it gets good and hot.. sudden loss of power (10-20mins of driving), and engine will stall. Try turning it over and it really labours, it will start but if you try to drive it - stalls. Leave it for 30 mins and it will start fine again, run sweet until it gets hot again them same loss of power. I am guessing that when the engine gets really hot (not nice touching the dip stick end - very hot) it is seizing.

All tinware is in place, new oil (15-40), new filter. tappets and timing set.

It is loosing/blowing some oil from the mechanical petrol pump (replaced with electric pump by previous) and I am guessing again that the diaphragm has gone and I should probably remove pump and blank it off.

What steps/tests can I make before having to remove the engine and strip it down?

Thanks

[faggie]

do a compression test and make shure the timing is set to factory settings , also make shure the thermostat is opening the flaps when it warms up or it could be overheating

[blacky]

do a compression test and make shure the timing is set to factory settings , also make shure the thermostat is opening the flaps when it warms up or it could be overheating

What Faggie said plus check crank has end float. Timing too far advanced could cause it.The thermostat should fail in the extended position so that the flaps are open but even if it's extended check flaps are open and not binding.If all settings are correct and belt tight it should be impossible for a vw Aircooled engine to overheat once flaps are fully open. Used to work at v.w. in Australia and we never had a problem.

[faggie]

its not the first time i have seen the cooling flaps have been fitted incorrectly or binding on the fan shroud