Hi there, I fitted a new pump last night and the symptons are the same. The old one when running sounded like it was knocking every couple of seconds, and the new pump (not OEM) seems to click every second or so like a dodgby relay. It started on the kick start, ran for 200 yards, then stopped and wouldn't start again until I left it 15m. The 200 yard distance seems consistent each time. I ran it very hard and it revs up well until it dies.
The oil temp light comes on when you drop the revs, but turns off when you raise the revs, and it seems to run for ages in the barn on tick over.
I made a mistake of running it off reserve so it could be bad/old fuel. I will drain the tank this weekend, and thanks for the advice on the carb. I'll try and find the tank drain bolt as you've said. I've ordered some new fuel lines as they are a cheap repair to try. I've never looked at a carb before to see the bowl but I'll google it. It should be easy to access to check for dirt, and I'll check the choke as well. It's warm here and you only need choke to start it, and then you can very quickly release the choke. The old fuel filter was very dirty (now replaced) and (I think) only cleaned the main tank not the reserve, as there are 2 fuel lines going into the pump (clearly I'm clueless!).
Is the petcock simply bolted on to the tank?
I still canít figure out why this issue would occur at exactly the same time as the starter failing. It was low on oil- could it be the fan didnít come on as the old unit failed, and tells the engine to stop? I guess itís just a coincidence.