after replacing heads , barrels , Pistons , manifold , fuel pump , spark plugs , you name it after my burnt out exhaust valve on number two , I've been going for little run in runs in the bus , for the second time (it did it last week ) after running like a Swiss watch for at least ten miles it cuts out , like running out of petrol ? Luckily today I was yards away from a layby, I start it up again and it ticks over very grumpy , but won't rev up much then cuts out , start up again won't rev and idles erratically I try to pull of no power cuts out ,, after about 15 mins of looking at engine, swearing, I get to the point where I can move back and forth up and down the lay by so I just go for it , home. , not so much as a splutter, fine back to Swiss watch , purring in fact ??? I'm at a loss , second time it's done it as I say ,, and a wedge drove past me wile I had my head in the engine toting his horn ,, oh the shame
when it cuts out you have to look for the suspect ,if you think it is fuel undo the hose from the carbe and turn the engine ,if some comes out catch it in a can etc.. Put it back and crank it ,if still no joy put the stuff you have collected down the spout and try again.. If it fires ,then it might be the "cut out" in the carbe sticking ,if it does'nt fire ,then it's electrical... Sitting on the sofa thinking "what could it be" is just a waste of time...
Did you replace the fuel pump pushrod (or check the length of it at least)? Otherwise key suspects are blocked fuel filter or tank outlet, or dodgy float valve in carb. As per @lost-en-france suggestion, next time it does it find out where there is and isn't fuel, will tell you where the blockage is.
You're right he wouldn't. But GSF still sell pump push rods that are 3mm too short. When coupled with a nice 'high quality' repro pump you don' get enough fuel. Equally old worn rods can struggle to operate the repro pumps.
This can be flooding due to leaking fuel needle valve. When it stops does it stink of petrol ? It can stop with too much as well as too little fuel..
When it conks out, is that just pottering, or after some foot down, maybe uphill or fast cruising action?
I was going round a big island third gear about to leave exit , so I suppose I was accelerating to exit
Old push rod , right length , machine 7 , posh fuel pump that's ethanol friendly, and you can take it apart ,
the carb needle valve could be sticking due to being worn out or dirt/rust in the fuel. is the fuel filter clean and fuel clear looking or does it look cruddy.
The Petrol in the tank was doing a centrifugal force (especially in third)when constanly turning left/right (pick one) thus clearing the tank outlet....
When I get chance this week I'll take carb of and clean seven bells out of it, and change fuel filter as well , see if that helps
It is most likely fuel starvation - third gear and leaving roundabout is probably a maximum amount of fuel flow. Next time try taking off the fuel tank cap and see if it sucks air from a vacuum in the tank when it does.. I bet you have crossed the beams.. no I mean the fuel tank breathers and simply have joined the ends together. Post a picture of the centre of the engine bay including the carburettor and the pipework and then it can be analysed and scored for artistic merit. Another thought is that a knackered fuel pump or a knackered pump connected backwards (should be in at top out at bottom) can sort of work while fuel levels are high in the tank.
