[Ady B]

Hi has anyone got any advice. Ive cleaned and rebuilt the carbs on my engine. It starts ok and runs well when given revs but I cant get it to idle. When I adjust the low speed mixture it doesnt seem to make any difference. The test tank has got a film of black oil on the surface now, could the oil pump be pumping to much oil? Its set so the marks line up at idle. Any help.
Thanks Ady B

[Laddies]

It sounds like a float related problem, possibilitys are float height or a inlet leaking. There is also a chance of a ruptured fuel pump diaphram.

[Ady B]

Thanks Laddies, I'll check fuel pump to see if problem is there. I have checked and reset float levels to 7/16" and replaced inlet needles as part of rebuild. Thanks again Ady B.

[Ady B]

Cheers Laddies, it was the fuel pump, tear in the diaphragm, thanks again
Ady B

[jmburock]

Don't lose those little plastic discs that come with the fuel diaphragm kit. The pieces have a way of getting lost. I always buy 2 of these kits when I know I'll be using one. These fuel pump diaphragms seem to go bad often, perhaps more often now in the days of ethanol-blended fuel. Plastic and 10% ethanol probably don't mix.

[bhile]

Those discs are the new style check valves. They replace the old rubber ones as ethanol causes the edges to curl up. Merc has a TSB out on it.