Logo
FULL SITE MENU

1986 evinrude 20 Need helps?

M

Matthewb

New member
It will plane out but then start to bog out shortly after. After I stop and idle for a few seconds it will take off and bog down again, the want to go but bog down again. I've cleaned the carb, changed fuel lines, tank, fuel tank, spark plugs and still can't get it figured out. Compression is low but within 2 psi.... Is the compression a bigger problem than I'm treating it? Or do you think the issue is elsewhere. Thank you for your input

e20crlcdc - rope start
 
Possible weak or leaking fuel pump. If you squeeze the primer bulb when it starts to bog down, does performance improve?
When you say you cleaned the carb, did you take it apart and clean all the small passages?
 
Matthewb said:
It will plane out but then start to bog out shortly after. After I stop and idle for a few seconds it will take off and bog down again, the want to go but bog down again. I've cleaned the carb, changed fuel lines, tank, fuel tank, spark plugs and still can't get it figured out. Compression is low but within 2 psi.... Is the compression a bigger problem than I'm treating it? Or do you think the issue is elsewhere. Thank you for your input

e20crlcdc - rope start
Click to expand...


Youtube be link to video. https://youtu.be/RrW7bsoYBhc
 
The bulb would flatten out so I changed the fuel pump and made sure the fuel line connections were snug. The bulb stays solid now and it has shown signs of improvement since. When cleaning the carb I stripped it down all the way and cleaned each piece with brake cleaner ... I tried my best to keep the brake cleaner off the plastic parts. All the gaskets were in good condition (changed them out 2 years ago)
 
Rebuild the fuel pump and surface the head and install a new gasket. Did you properly check/adjust engine sync after installing the carb? When the mark on the throttle cam is center of the roller the carb butterfly should just begin to open as it passes center of the roller
 
Matthewb said:
The bulb would flatten out so I changed the fuel pump and made sure the fuel line connections were snug. The bulb stays solid now and it has shown signs of improvement since. When cleaning the carb I stripped it down all the way and cleaned each piece with brake cleaner ... I tried my best to keep the brake cleaner off the plastic parts. All the gaskets were in good condition (changed them out 2 years ago)
Click to expand...

Therein lies your problem! The only fault that will result in having the fuel primer bulb draw flat is a fuel restriction.

Either you're using a portable fuel tank and the vent is not open..... you're using a built in tank and the anti-siphon valve is stuck shut.... or the outlet fuel valve of the primer bulb is faulty.
 
I agree. There was nothing wrong with your original fuel pump. In fact, it seems like it was working better than the one you replaced it with. It was trying its best to draw gas from the tank, but could not because something is preventing the gas from flowing from tank to bulb. But the pump continued to suck, creating a vacuum inside the bulb, and flattening it. Find what is blocking the fuel flow to the bulb, and get your eyes off the carburetor.
 
Back
Top