26-05-2021, 08:27 AM
(This post was last modified: 26-05-2021, 08:31 AM by andrew34ruby.)
(26-05-2021, 08:08 AM)John Cornforth Wrote: Hi
There is also the remote possibility that the exhaust system is partially blocked, which will build up back pressure.
The symptoms for a blocked exhaust are generally that it will start and tick over all day, but not rev much.
(26-05-2021, 07:59 AM)12jslater Wrote: its definitely compression, the engine will just suddenly run worse, refuse to rev and cut out over a couple of seconds.
Try dribbling petrol into the air intake during that couple of seconds. It sounds like a shortage of petrol, so might be worth feeding the carb from a bottle hung above, to eliminate the tank, pipe and pump.