I'm from the Netherlands and purchased a 4 hp '94 two stroke Merc. Worked ok for years. Then it began to stall suddenly from time to time, mostly at full throttle. After a few pullings the engine would start again and was running ok?. I checked the vent (running on internal fuel) and the flow of gasoline. Nothing wrong there. The problem became more frequent en sometimes the motor did not now start after a few pullings. I had to get the choke all out, then pull a few times, put the choke back en then there was a possibillity of starting again. Note this is with a warm engine!
I cleaned the filter behind the fuel valve. There was water in it en a lot of dirt. The second round plastic fuel line filter seemed ok?. The carb itself was relatively clean, but there was a bit of water in the rectangular vacuum(?) pump. The rubber membranes were not damaged but seemed a bit slack.
It did not help to my surprise. After 40 minutes of full throttle the engine stalled again suddenly. It would run a few seconds on an extended choke and then died. After ten minutes of trying the motor was running, but when engaging the gear it died time after time.
I released the line filter (I sawed it open at home, 99% clean!) and arranged a more straigt fuel line without loops. Motor did run ok? by then.
Note that there is never any spluttering or misfiring, it is an on/off situation. Can it be that this type of carb is very sensitive for airbubbles, maybe waterdrops or loops in the fuel line???
Any idea folks?
I cleaned the filter behind the fuel valve. There was water in it en a lot of dirt. The second round plastic fuel line filter seemed ok?. The carb itself was relatively clean, but there was a bit of water in the rectangular vacuum(?) pump. The rubber membranes were not damaged but seemed a bit slack.
It did not help to my surprise. After 40 minutes of full throttle the engine stalled again suddenly. It would run a few seconds on an extended choke and then died. After ten minutes of trying the motor was running, but when engaging the gear it died time after time.
I released the line filter (I sawed it open at home, 99% clean!) and arranged a more straigt fuel line without loops. Motor did run ok? by then.
Note that there is never any spluttering or misfiring, it is an on/off situation. Can it be that this type of carb is very sensitive for airbubbles, maybe waterdrops or loops in the fuel line???
Any idea folks?