To-day 22nd August I finally got my Yamaha 50 running smoothly. I say I but it was the engineers at Althorne Marine who solved the problem. A carburetor jet had broken off (been broken by person or persons unknown)? and this was the cause of the problem.
I thank everyone for their help and suggestions, many of which my engineers tried until in desperation they started to strip down the carbs and discovered this 'missing' jet.
I have a lot of catching up to do on the water but first I must head to Scotland in my 20 year old Porsche Boxster to take on the North Coast 500. I will be returning home along Loch Ness and through the Lake District, far too late for the BigMac.
I will have something to look forward to on my return in 2 weeks, apart from the bill.
I am about to fit a new fuel pump to mine to see if that can get it running above 4000 rpm under load. It runs up to the rev limiter under no load (neutral) but when in gear it starts spluttering at about 3600 rpm and not get beyond 4000 rpm. I've tried lots so far (carb rebuild, inlet manifold O rings, new fuel lines, new 10 micron fuel filter etc) so I am wondering if there is just not enough fuel getting through under load.
Under low power / throttle it's a great engine. Starts well, ticks over like a dream.
Hi, David, You may have gathered that I am no expert on engines and spend most of my 'pocket money' on paying other people to sort out my problems.
Just a thought before you get a new fuel pump but is your prop standard size or has a bigger one been installed? There was a discussion on this site not long ago about propellers. There are some members expert in these things.
Pesky things aren't they; fine when they work and a damned nuisance when they don't.
To-day 22nd August I finally got my Yamaha 50 running smoothly. I say I but it was the engineers at Althorne Marine who solved the problem. A carburetor jet had broken off (been broken by person or persons unknown)? and this was the cause of the problem.
I thank everyone for their help and suggestions, many of which my engineers tried until in desperation they started to strip down the carbs and discovered this 'missing' jet.
I have a lot of catching up to do on the water but first I must head to Scotland in my 20 year old Porsche Boxster to take on the North Coast 500. I will be returning home along Loch Ness and through the Lake District, far too late for the BigMac.
I will have something to look forward to on my return in 2 weeks, apart from the bill.
Enjoy the rest of the summer, I intend to.
Simon Armitage
Sowenna 26m
Well done Simon (or his engineer)
I am about to fit a new fuel pump to mine to see if that can get it running above 4000 rpm under load. It runs up to the rev limiter under no load (neutral) but when in gear it starts spluttering at about 3600 rpm and not get beyond 4000 rpm. I've tried lots so far (carb rebuild, inlet manifold O rings, new fuel lines, new 10 micron fuel filter etc) so I am wondering if there is just not enough fuel getting through under load.
Under low power / throttle it's a great engine. Starts well, ticks over like a dream.
David Kirk
26X Glissando
Dumfriesshire, Scotland
Hi, David, You may have gathered that I am no expert on engines and spend most of my 'pocket money' on paying other people to sort out my problems.
Just a thought before you get a new fuel pump but is your prop standard size or has a bigger one been installed? There was a discussion on this site not long ago about propellers. There are some members expert in these things.
Pesky things aren't they; fine when they work and a damned nuisance when they don't.
Good Luck
Simon Armitage
Sowenna 26M
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