1978 Merc 20 HP - Stalls - Losing it's prime

[daspin]

Hi all. Looking for a little help. I bough a little fishing boat with a 20 HP merc on the back. It seems to run great, except a couple issues I was hoping someone could help me troubleshoot

1. When I am driving at high throttle, it starts to die out and stall, unless I pump the primer ball, then it will keep going. I have to do this every couple minutes to keep it going. I changed the hose and priming ball. It's also new gas, and the vent is open on the tank. I did not change the fittings on the hose or tank though. Used the old ones.

2. Probably related. If I turn it off and let it sit for only 5 minutes, it's difficult to get going again, and I need to prime it and choke it again. All seems to revolve around the priming.

Any help would be greatly appreciated.

Thanks so much

 

[Guest]

Is your primer bulb get soft? if it does most likely a line problem. But could also be a carb or fuel pump issue

 

[Mi duckdown]

Time for a carb and fuel pump kits and rebuild.

 

[daspin]

The bulb does get soft. But I just replaced it yesterday. Carb and fuel pump? That sounds expensive. Thanks guys

 

[racerone]

Repair kits are not expensive !!

 

[Guest]

I would check all the lines and hose clamps before buying anything. There may be a leak which is letting air in. Once you eliminate that part from being the problem move onto the next step (carb rebuild kit) then fuel pump. Looks like when you squeeze the bulb you get the gas into the block but then there is no suction to continue pumping fuel from your tank

 

[daspin]

Thanks guys. I tried a whole new tank and line and it's still doing it. It seemed to run pretty good today but man was it difficult to start. Choke and prime over and over. Couldn' kept being very difficult to start even after running it and stopping to fish for a bit. And then would seem to lose power as I was driving it again, but not as bad today. I guess I should bring it to a mechanic to get the carbs and fuel pump checked like you guys suggested.

 

[Guest]

If you can fish and tie knots I an positive you can do it yourself and save labor and potentially mechanic rip-offs. But if you feel you cannot complete the task then bring it to one