Should this be in technical?
Its an engine problem but I dont know much about them.
I've got a Bond minicar with a villiers 250 engine and I have a little problem. Every now and then engine starts to rev really high as if the throttle is stuck. I've had the cable off and its free as a bird so I'm thinking it could be carburettor related. As I said I dont know a great deal about these things so I thought I'd ask before stripping it down.
Thanks
Amal carb? If so there should be a large weakish spring between the top of the carb and the throttle slide, we used to give them a bit of a stretch when they got too weak. The guy that I would ask as he used to run these is living on a boat on the Broads somewhere so can't ask him. The throttle slide could stick if a piece of grit got caught between the slide and body. (especially if running without an air filter!)
Service kits for Amal available here http://amalcarb.co.uk/
Pretty much what OBG said. The slides and bodies wear and after maybe thirty or forty years it's quite likely. If they wear the slide can sort of tip a bit in the bore and stick.
And using petrol containing Ethanol is bad for those early Amal carbs due to the metals used. It can cause that throttle slide to be more prone to sticking (I have read about this numerous times on classic bike forums). Most "premium" grade petrol does not contain Ethanol, although all Shell petrol does contain it Amal sell a kit of bits to make their older carbs "Ethanol proof".
Thanks for that chaps. Don't think its an Amal carb, can only see villiers written on it and it doesnt look like any of the ones on the Amal website. Must all work in a similar way
I had one in a bond when I was 15 44 years ago, was there a guide screw in the body of the carb that kept the slide straight,might be to tight or a rough piece on the slide ,,,,,or I might be talking out of my a*** it was a long time ago before the diesel fumes started affecting my judgement
Amal sell a kit of bits to make their older carbs "Ethanol proof".