Classic 40hp Merc 1981 stalls when given throttle in gear

[Utilityrunabout]

Motor starts fine every time and idles but when put in gear and throttle it dies. Only way to get full speed is to baby it very slowly to get to full power, or she dies.

Once motor has been at full speed the problem goes away. Runs well once it gets to full throttle. Able to throttle down and up.

but - always occurs after motor has been shutoff (like after return to dock). On restart...the motor stalls when you give it throttle.

Not sure where to start. Any help appreciated



Thanks !

 

[Fishcake42]

Re: Classic 40hp Merc 1981 stalls when given throttle in gear

Been having similar problems just recently. There are a number of possibilities here, although I would suggest a fuel supply issue. The reason being, that if, once you get her up the RPM scale, she starts to behave normally, that would imply the fuel pump working faster helps the state.

Always do the basic tests - do you have spark on both cylinders, and is compression good. (+100psi and +\-5psi between)

Two man test - start engine and get someone else to pump primer bulb while you increase the throttle. If that helps, think fuel pump/primer bulb)

This test didn't help mine. I then explored the carbs, which were clean, which led me on to check the timing - which turned out to be completely out. Reset timing with timing light and it's 100% now.

Hope that helps