Constant power loss and stalling. 83 evinrude 20hp

[ex0r]

As the title states, I'm having an impossible time keeping the boat running. Hooking up the muffs it seems to want to run a bit better, but as soon as it's in the lake it completely loses all power.

Even with the muffs on, it has a rough time staying running and/or idling. When I get it out into the lake and go wide open with it, it takes off for a few seconds, then bogs right down, and most of the time stalls out. I also cannot leave it in neutral under load without it stalling out.

I spent an hour on the lake today trying to open it up to clean it out, and I had to constantly pump the primer on the key switch to keep it running or it would die right out. After it dies down from going full open (even with it still being in full open), and I shift into neutral, after about 2-3 minutes I can go full open again but only for a few seconds before it does it all over again.

The motor is also shaking quite profusely the entire time. So much so that the back of the pontoon shakes with it.

Getting frustrated figuring out what's wrong with it. Been trying to look at information online but I can't find much for this old of a motor.

 

[Jugfisher]

Do you have an inline fuel filter . Sounds like it's not picking up enough fuel under a load.

 

[flyingscott]

Try pumping the primer ball while this is happening if it runs better probably the fuel pump.

 

[ex0r]

I've tried pumping the ball. Doesn't appear to effect it. It's one of those self venting dura tanks. As far as the filter, I don't believe it has an inline one. On the side of the engine there's. Black plastic circle with a silver thumbscrew on it. Removing this reveals a silver screen which I believe is the filter. Appears to be clean.

 

[racerone]

Check compression.-----Check for strong spark on both leads.----Does primer bulb go hard , yes or no ?----The black plastic circle is mounted on the fuel pump.---Check the diaphragm in that pump.

 

[ex0r]

The bulb doesn't go rock hard but it gets somewhat stiff. I can still squeeze it with one hand at all times. Compression was fine when I checked it. Not sure how to check the diaphragm

 

[juno pierrat]

ex0r, the site i check for parts doesn't show a 20hp for 83", a 25hp yes, do you have a model number?

 

[ex0r]

Im positive it's in the 83-84 year range. I don't have a model or serial number, most of the identifying markings on it have been removed or replaced with decals/stickers.

The shop I went to to get the water pump for it said it came from an 83 to 94(?) evinrude (OMC) 20hp

 

[ex0r]

No Title

Here is a picture of the motor with the cover off of it

 

[racerone]

The bulb must go hard !----Remove pulse hose to pump.----Squeeze bulb.----Does any fuel leak out of the pump ?

 

[ex0r]

Should it get rock hard to where you cant even squeeze it anymore? Yesterday thinking it was the bulb I removed the line from the engine and pumped the bulb and fluid shot out of the end of the hose. I am not at the motor right now, but I do know when I removed the black circle with the thumb screw from the fuel pump yesterday and put it back on, I didnt have it lined up right, and when I pumped the bulb, the fuel shot out of between the black thing and the fuel pump, so fuel is at least getting to that point.

 

[racerone]

Test this motor with a know to be good hose and fuel tank.-Perhaps borrow a set-up.

 

[Dizz]

I had exact same issues on the 91 Erude 15HP.The carb had been rebuilt by a shop in SC,I cleaned out,same again.
The last guy had left the tank&hose in boat.The fuel hose was aged,and putting black specs in the carb from the inside,Outside of hose looked fine,but stiff.
When I took the carb bowl off,dumped on new paper towel,I saw the black specs.
Maybe not your issue??

 

[Jugfisher]

Have you checked the spark yet? You need to get a spark tester and make sure you are getting a strong spark from the plug.

It still sounds to me like a fuel issue.

Open the fuel pump and look at the diaphragm. This will be a mesh style screen locate inside. You will know it when you see it. Make sure it is not dirty or torn. The silver screen does a decent job of.keep in foreign objects out but the small particles can still get through. Does the engine have a choke on it? If so will it idle while on choke?

 

[ex0r]

So... I'm an idiot and a complete noob. I was able to fix the problem. apparently, the pump doesn't have enough power to pump from the hose when it's below the fuel tank level. I took the hose, which is rather long, and fed it up through the uprights on the pontoon so all of the hose is above the fuel tank and filler in the motor, and it now runs without stalling and I can get forward and reverse motion on it. 20hp really isn't very good for moving a pontoon along. With about six people on it we were only doing about 5mph at full throttle.