40hp Mariner running rough!

[Shrimpy]

Changed plugs, Stripped and cleaned carbs but its still got a mind of its own, checked the fuel pump and found 2 holes. Is this -



The cause of This? -

https://www.youtube.com/watch?v=Mpb-BwfeLw0

[ShinyShoe]

So thats presumably the fuel pump diaphram... ..holes will mean poor pumping and so irregular fuel supply...

[Sunstreaker]

Did you notice any difference after your carb clean?

[Shrimpy]

Originally Posted by Sunstreaker

Did you notice any difference after your carb clean?

No, same symptoms, checked for poor fuel hose connections/tears in pipes etc and looked at every electrical connetion/wire . Will be changing the fuel pump anyhow,I'm just hoping that its the cure

[Nos4r2]

Doubt it's the cure,unless it suddenly improves if you pump the primer bulb.

[TrevorB]

Shrimpy looks like we have the same engine 1990 vintage, mine is bad at idling when warm
I have replaced the plugs squirted in carb cleaner, checked the auto advance is not stuck

Thinking I should check if it has contact breaker points but the mag is below the big flywheel nut so I suspect an extractor is needed to go there

[uncle al]

be carefull usually when those pump diaphrams leak like that the fuel goes into the crankcase and it is a dangerous situation.