1985 50hp Mercury Outboard - low power @ WOT

[JoeCanada]

I just bought a boat and motor and tried it out for the first time this weekend. I've been around boats a fair bit but this is the first one I've owned. The engine hadn't run in awhile but started fairly easily and idled nicely.

I noticed that there are two throttle cables, one going to the neutral throttle control and another going to the main throttle control for when you have it in gear. When I have the boat in wide open throttle on the main control, it kicks into gear where it should, but there is no real thrust until I get to about 60% of the range of the throttle control. As a result, I don't think its revving up to its full potential and is barely getting up on plane. When I use the neutral throttle I get nice even acceleration right through the range and I can get high revs. This made me think I need a throttle cable adjustment on the main cable.

There was another thing though. When driving along in wide open throttle the engine would lose power and rev way down, until eventually I was creeping back to shore at about 10kmph with the throttle wide open. I also noticed that the primer ball was not staying hard during all of this.

I'm thinking I need to replace the fuel line/primer ball and get the throttle adjusted. What do you guys think?

Joe

 

[latin monkey]

Re: 1985 50hp Mercury Outboard - low power @ WOT

it would be a good idea to go ahead and rebuild the fuel pump too

 

[JoeCanada]

Re: 1985 50hp Mercury Outboard - low power @ WOT

Does the neutral throttle working perfectly not rule out fuel problems for the most part though? There's only one fuel line.

 

[latin monkey]

Re: 1985 50hp Mercury Outboard - low power @ WOT

could be having a problem pumping under a load. changing fuel line and bulb is a good idea, also make sure fitting on tank is tight

 

[JoeCanada]

Re: 1985 50hp Mercury Outboard - low power @ WOT

bump

 

[JoeCanada]

Re: 1985 50hp Mercury Outboard - low power @ WOT

Ok so I changed the fuel line and primer ball and I got a huge improvement in performance. I thought I had the problem solved because everything seemed to be working properly. Then I lost power at wide open again, I checked the primer ball and it was soft, so I pumped it a couple of times while I had the engine running and the throttle still wide open and it took off again and ran perfectly.

Anyway I think you're right about the fuel pump. Where can I buy a fuel pump kit?

Joe

 

[huntxtrm]

Re: 1985 50hp Mercury Outboard - low power @ WOT

right here, look under boat parts and accessories.