1988 25 H.P. Evinrude Carb Problem?

[ak_country2003]

I have a 1988 25 H.P. Evinrude Outboard (U25RWLA) that idles okay once you get it started but when you hit high R.P.M's it bogs down. It was my grandpa's machine and was in storage for at least several years. The top cylinder gets a little bit of gas/oil on it but the bottom cylinder stays dry. I wanted to know what is the proper way to adjust the carburetor to get it running just right, and wanted to know what the screw just above the carburetor hole is and what it is used for? I think it's called the valve needle? I'm not sure if there is any dry rot to the gaskets. It is in fairly decent shape for it's age. Any help/suggestions would be greatly appreciated. Thanks in advance.

 

[ONERCBOATER]

Re: 1988 25 H.P. Evinrude Carb Problem?

if your bogging down as you try to speed up then your high speed jet is clogged or your fuel pump or filter isn't getting fuel to your carb in sufficent quantity to sustain high speed operation.
answer.... remove carb, disassemble clean very very well,
remove fuel pump, disassemble clean very very well.
fuel filter most likely part of fuel pump on this model.

DO NOT RUN if you can not get fuel/oil to all cylinders.... you will destroy the motor if you do

the needle valve above the carb should be your low speed mixture control, clockwise should make mixture leaner, counter clockwise should make it richer... only affects the low speed area and is used to assist with cold start at a richer setting then moved to get smoothest idle when it warms up.

Suggest you get a repair manual, a real one not a seloc or clymer manual for your engine. I am not saying this because we won't help you, but because it will really make your life easier.
also I would suggest reading any thread here that relates to an evinrude/johnson engine between 1970 and 1990 to familiarize yourself with the tech, and the way that OMC built their engines.
Sean