1985 Evinrude 20HP Problems

[Jdkxtreme]

Not for sure how long this boat sat before I got it. The guy I got it from traded for it and knew nothing about it. Things I have done to it,
New fuel Tank, New fuel line and Primer bulb, Rebuilt Carb. New Fuel pump. Bothe new coils, New wires and spark plugs.

Kinda hard to startin the water. When at the lake it will take off good and pop ( Not for sure if thru carb or exhaust ) Then after 20 or so feet it will start to slow down. to a little above an idle. You can wait and try it again and will take off and do the same thing. If I leave it on the trailer and back it in the water and leave it in netrual and hold the throttle wide open it will do the same thing. Run for a few then slowly die down. I'm at a loss. The motor looks good and clean, I am sure it's probably something simple. Any suggestions would be great.

Or else I may fill it with dirt and cedar trees and pull the plug and use it for a crappie bed next season..

Joey

 

[Jdkxtreme]

Re: 1985 Evinrude 20HP Problems

Not for sure how long this boat sat before I got it. The guy I got it from traded for it and knew nothing about it. Things I have done to it,
New fuel Tank, New fuel line and Primer bulb, Rebuilt Carb. New Fuel pump. Bothe new coils, New wires and spark plugs.

Kinda hard to startin the water. When at the lake it will take off good and pop ( Not for sure if thru carb or exhaust ) Then after 20 or so feet it will start to slow down. to a little above an idle. You can wait and try it again and will take off and do the same thing. If I leave it on the trailer and back it in the water and leave it in netrual and hold the throttle wide open it will do the same thing. Run for a few then slowly die down. I'm at a loss. The motor looks good and clean, I am sure it's probably something simple. Any suggestions would be great.

Or else I may fill it with dirt and cedar trees and pull the plug and use it for a crappie bed next season..

Joey

Any suggestions at all?

 

[Jdkxtreme]

Re: 1985 Evinrude 20HP Problems

I also forgot to mention that if running at WOT and it starts to bog down I can pull the manual primer once and it picks back up.

 

[danoutbard]

Re: 1985 Evinrude 20HP Problems

Dont quit on the motor, I think the problem might be a fuel restriction but, again start with the basics : compression spark & and fuel in that order
Good luck

 

[2manband]

Re: 1985 Evinrude 20HP Problems

If the manual primer solves the problem, that's usually indicative of a fuel pump problem. Take the pump off, and try to blow air into the outlet side of the pump. If any air is allowed through, you've got a seal somewhere in the pump that isn't sealing. (You should be able to blow air through the inlet side - that's normal) Also, I'm talking about blowing with your lungs - NOT AN AIR COMPRESSOR - that amount of pressure could cause damage.

Maybe you got a faulty pump or have a leak somewhere in the fuel line connections.

If the pump checks out, then you may have an issue with the power pack or the trigger/coil under the flywheel. Check for spark when the engine dies.

 

[Jdkxtreme]

Re: 1985 Evinrude 20HP Problems

If the manual primer solves the problem, that's usually indicative of a fuel pump problem. Take the pump off, and try to blow air into the outlet side of the pump. If any air is allowed through, you've got a seal somewhere in the pump that isn't sealing. (You should be able to blow air through the inlet side - that's normal) Also, I'm talking about blowing with your lungs - NOT AN AIR COMPRESSOR - that amount of pressure could cause damage.

Maybe you got a faulty pump or have a leak somewhere in the fuel line connections.

If the pump checks out, then you may have an issue with the power pack or the trigger/coil under the flywheel. Check for spark when the engine dies.

The pump checks out good. 120PSI on both. the motor never dies all the way. I can hold it at above an idle all day.Runs great for about 40-70 feet. Acts the same way in the water in netrual.
Great spark.

New fuel,Tank, Bulb, Coils, Plugs, Wires, Fuel Pump

 

[dodgeboy1979]

Re: 1985 Evinrude 20HP Problems

i am assuming the breather on your fuel tank is left open as well? have you changed the fuel lines at all?

 

[Jdkxtreme]

Re: 1985 Evinrude 20HP Problems

i am assuming the breather on your fuel tank is left open as well? have you changed the fuel lines at all?

It is open. I have even opened the cap to make sure it is vented enough. Most of the fuel lines have been replaced. The only ones that have not are the ones on the primer. Is there a way to disconnect the primer completley to see if that is the problem?

 

[nwcove]

Re: 1985 Evinrude 20HP Problems

what do the plugs look like immediately after it bogs? sure sounds like a fuel issue, but power packs can do some weird things also.

 

[Jdkxtreme]

Re: 1985 Evinrude 20HP Problems

what do the plugs look like immediately after it bogs? sure sounds like a fuel issue, but power packs can do some weird things also.

Have not pulled the plugs.And it never dies. just boggs way down.. It has new plugs in it now

 

[Jdkxtreme]

Re: 1985 Evinrude 20HP Problems

Is it possible to undo the primer to see if that is the problem somehow?

 

[oldman570]

Re: 1985 Evinrude 20HP Problems

Try replacing the fuel line from the pump to the carb and run the motor. When it bogs down look at that line and see if it is full of fuel or if it has air bubbles in it. If it has air bubbles then you have a fuel resitiction or a air leak in the fuel system. Also take the primer bulb and place it in a vertical position with a clamp or duct tape to see if the check ball in it is causing the trouble. If there is nothing but fuel in the clear line then the fuel system from the carb back should not be the trouble and the float in the carb could be set to high and should be lowered some. After fixing the trouble remove the clear fuel line and replace it with line made for ethenoal fuel. JMO
Oldman570

 

[Jdkxtreme]

Re: 1985 Evinrude 20HP Problems

Are you talking about bulb from the tank to the motor? If so its new. I will check it thought. And I will try to find some clear fuel line somewhere

 

[Jdkxtreme]

Re: 1985 Evinrude 20HP Problems

Just went out to start doing some of the things I was asked to do. I found this fitting on the fuel pump. It looks like someone has used it for an elbow. one side is larger than the other. The nipple on the fuel pump outlet is maybe 1/4' and the size of the nipple on the elbow going to the carb bowl is maybe 1/8. These are only guesses as to the size. But it is a big difference. Could the carb be starving for fuel?

I will try to attach a pic of the elbow

 

[oldman570]

Re: 1985 Evinrude 20HP Problems

The fuel line and all fittings should be atleast 1/4", and 5/16"would be better, all the way from the tank to the carb. The fitting made on the pump should inducate just what size of line is the smallest that should be used. If the fitting has a smaller nipple as shown, then I would change it out for one that has both nipples the size needed. Sometimes the check ball in the primer bulb will not set as it should in just one end of the bulb and will cause trouble if the bulb is in a horazontal position.
Oldman570