1974 Mercury 1500 Ran good on muffs died at lake

[elark7]

I think I know what to do to fix my problem but I want to get the opinions of some of this sights experts. This motor ran good on the muffs at home at idle and low speed for about 10 minutes. Went to the lake and it took a lot of choking and the cold start lever had to be up at the neutral point to get it to start. Then ran good until I got halfway across the lake. Then it stuttered and sputtered and died. It started a couple of times but died under load. It would not start and run after that.

I took the cover off and watched as my son tried to start it. It was then that I noticed the bottom carb leaking at a steady stream. When I squeezed the primer bulb it got worse and the middle carb began to leak as well. While leaning out the back I also noticed water and exhaust coming out of the square hole of the center tube?

So based on my limited boat experience, but better car knowledge, I would say the carbs need pulled and rebuilt, and the floats set. Bottom carb has a stuck float and probably dirt in the passages. Middle carb is going bad. Top may be ok, but best to do them all. Then run seafoam through the engine.

It has the single fuel pump on the side of the lower cover. Should I just go ahead and rebuild it while doing the fuel system? Should I worry about the exhaust and water coming out of the middle? I think I read a post where this was normal but could not find it today. I now await your expert advice and opinions as to if I am right or wrong and any points that I may also try in order to fix this motor. As always thank you for the help.

elark

 

[Barnacle_Bill]

Re: 1974 Mercury 1500 Ran good on muffs died at lake

Sounds like you are on the right track. I would do the pump too as kits are cheap and then you will know its good.

 

[elark7]

Re: 1974 Mercury 1500 Ran good on muffs died at lake

I messed around with this motor before coming to work and was stumped. It started right up and the bottom carb was acting normal. The middle and top ones were both dripping off of the bottom right jet screw, although it could be from the gasket above. I did not put it in gear but gave it a little gas, no change. So I let it run for a while then it died. It would start right back up, but only run if I advanced the throttle a little, about 900-1000 rpm's. Anything lower, like back to the idle stop screw would kill it. But it would start right back up again, throttle advanced. So is this still the carbs or am I looking at some other problem.

elark

 

[hkeiner]

Re: 1974 Mercury 1500 Ran good on muffs died at lake

I'd say clean the carbs, rebuild the fuel pump, and do a link and sync to make sure all adjustments are set correctly. You need a shop manual to know how to do the link and sync. If the motor still does not run right, then it would be time to troublshoot further. Just my thoughts.