Evinrude Carborator Rebuild 50HP/1989

[Otte]

No Title

After I did all this measuring and adjusting I fired up the old girl. I was disappointed in the results. The engine was running rough and I was stumped. I continued to play with the engine while running. I pushed the throttle cams and that got higher revs but it was still running rough. I was noticing smoke and heaving greasy mix coming out the exhaust areas. When I pushed the carb throttle shafts the engine ran more smoothly.

Remember I am a novice and learning all about engines with this '89 50 horse. Its been a summer crash course for me. So I start putting things together - more air to gas and it runs well... heavy smoke without playing with the carb throats. I figured it had something to do with the carb adjustment screws. On this outboard there are three jets but only one is adjustable. The Seloc service manual called the adjustable jet the "intermediate screw/jet" and that threw me off thinking it took care of speeds between idle and WOT. With some looking the OEM manuel called the adjustable jet the idle adjustment! Ah ha now I am learning.

So I turned both screws out on each carb 2 3/4 full turns from the fully seated position in the carbs. Started the engine and got it running by using the warm-up lever. I kept turning the screws in until the engine died, re-started the engine, lowered the warm-up lever and turned the carb screws in again until the engine died. I repeated this process until I got the engine running well with the warm-up lever all the way down. Now it starts up with a single turn of the key and seems to be purring like a kitten. I admit I raised both arms in the air like I had won a gold medal and I am not ashamed to admit it.

So now I have to get it in the water with a tachometer to to the spark advance tests. Wish me luck... please I beg of you.

I included a picture of the adjustable screw/jet so some of you not in the know can learn from my experience.

 

[Otte]

So in order to get the engine running well to this point I have done the following.
1. New fuel pump - VRO to mixed fuel pump conversion. The VRO pump went bad and I did not want to spend the $200-$300 on a new or re-build VRO.
2. Carb kit re-build from iboats for both upper and lower carbs.
3. Linkage adjustments as I outlined above using the ebay service manual.

Yet to do to finish the process...
1. Idle Speed advance
2. Maximum Spark Advance

Any thoughts on the Maximum Spark Advance? The OEM service manual called for this to be done with a test propeller ($300-$400!) at a minimum of 5000 RPM in the forward gear.
1. I assume this is done in a test tank and not on the water?
2. Is it safe to assume that if I get the Idle speed timing right that the maximum spark advance would be correct as well?
3. Is there a way of testing the maximum spark advance without a test propeller? I think I recall something in the evinrude stickies but the process outlined did not fall in to place in my brain.