Took out my 5hp 1970-71 Sea King (Clinton Engines Corp.) Need some help,

[hunter87]

Could my gas/oil mixture be hindering the performance of my motor?

Took the 12 footer out for the first time on a mountain lake this weekend, I was happy with the boat and the trolling motor, but I don't think my Sea King is running at its full potential. It fired up every time but throttling up to anything above medium seemed to just make the engine get louder, no increase in power.

I used a 1:32 ratio and didn't run the motor full throttle. A couple of times the exhaust came out real smokey and now that I look at the port I can see what I would describe as "carbon build up" (black exhaust build up around the ports). I could see the ports putting out moisture and I've tested the motor before in a bucket to be sure the impeller isn't bust and it appeared to be in working order.

Any help would be great, I'm a total newbie.

 

[SeaKaye12]

Re: Took out my 5hp 1970-71 Sea King (Clinton Engines Corp.) Need some help,

Could my gas/oil mixture be hindering the performance of my motor?

It fired up every time but throttling up to anything above medium seemed to just make the engine get louder, no increase in power.

I used a 1:32 ratio

Are you familiar enough wioth the motor to know poor performance when you see it? Those single cylinder Clintons probably won't perform like a 5HP OMC or Mercury. It might be giving you all it's got?

Things you can look for:
(1) Carbon build-up; like you say could be hindering exhaust flow...and might also be causing loss of compression past the piston rings. Read-up on de-carbing procedures. It certainly couldn't hurt.
(2) Dirty Carb. If your main jet circuit is partially obstructed it could keep the engine from developing full power
(3) Issues with the prop; can it's design allow slippage?
(4) Ignition issues. Might try running at night to see if spark is leaking somewhere (arcing)

I would run 24:1 in it if it were mine unless your manual says to run leaner.