55hp losing then regaining speed!!

[ryan04]

I have a 1969 55hp evinrude. I took it out on the water today and it started great, shifted great and away we went. The only thing is when it was on full throttle, for 55hp it seemed to be moving not nearly as fast as it should. I turned the boat around and as it turned the boat slowed way down, I mean way down and the throttle was open all the way. Then I straightened out and the power slowly came back. I've cleaned out the carbs, put in new fuel lines, I run 50:1, I adjusted the carbs to run a bit lean to clear up the exhaust, but should I get it adjusted at a mechanic? could that be it? Also somebody suggested it's because my lower leg is a 15" instead it should be a 20", he said that's probably why it had a lack of power. The stabalizer fin is about 3" above the bottom of the boat, but the prop is way under the bottom.<br />Any thoughts on what should get done, or what I should check? thanks

 

[REELSPORT]

Re: 55hp losing then regaining speed!!

You might try idle speed with the muffs on and pull off one spark plug wire at a time and see if you have a noticable change in motor. Could be you are running off 2 cyclinders. I have a 69 55 rude also. keep us posted on how you make out.

 

[ryan04]

Re: 55hp losing then regaining speed!!

I'll let you know on tuesday night. I'm going to be working on it again, I'll pull the plugs then. By the way how's your 55 running now? I"m curious because I need someone to bounce info off of, seeing as how your situation sounds exactly like mine. Thanks reelsport.

 

[ryan04]

Re: 55hp losing then regaining speed!!

So I pulled all the plug wires on the outboard while it was running. Number 1 it didn't change, #2 It killed the engine right away and #3 The engine sputter and almost stalled. I found that My spark plug in cylender one was covered in oil and it was fouled. During the week the gasoline in the tank is evaporating and leaving the mixture a bit heavy on the oil. So I cleaned the plugs and adjusted the timing and dumped it in the water. Instantly a 100% increase in performance. The only thing is the engine going into turns, would stay reved up but slow down dramatically. why is that? Once I straighten out the power slowly returns. Also what should my RPM'S be at when I'm WOT?

 

[Barnacle_Bill]

Re: 55hp losing then regaining speed!!

WOT on that motor should be 5000 RPM. I would imagine you are having problems in turns because the lower unit is too short as you described.

 

[ryan04]

Re: 55hp losing then regaining speed!!

sweet. Two more stupid questions should do the trick. What should the idle rpm's be at and what kind of speed Should I be getting out of this thing? I know every engine varies but what is the typical speed? Thanks

 

[REELSPORT]

Re: 55hp losing then regaining speed!!

Ryan rpm should be between 650-700 in the water.<br />my girl is missing on #2 cylinder seems to be misfiring although I have 130 lbs of compression on each cylinder. I have just changed plug wires<br />and I can tell a difference in the sound of the motor on muffs but I have not put it in the water yet. But as a wise boat motor mechanic told me not long ago anybody can get a boat motor to run out of the water, but getting one to run in the water is quite a different matter.<br />Keep me informed on how yours is doing since we have sister motors.

 

[ryan04]

Re: 55hp losing then regaining speed!!

I'm installing the tac on saturday, and I'll let you know what I get to as soon as I pull it out of the water.