50hp Sea Horse Gas Guzzler

[gferail]

I have a 1958 Johnson 50hp Sea Horse that was given to me last year along with a 1968 Larson 15ft boat. With a little work we got them both in the water and running this summer. The motor runs great and is very strong but it’s a gas guzzler. Is there anything I can do to cut down on the gas consumption? I think I read on the forum that changing the prop may help. Also is there a tilt and trim system out there that will work with this engine? Any help would be greatly appreciated.

 

[R.Johnson]

Re: 50hp Sea Horse Gas Guzzler

On most outboards today, 10% of the horsepower would be the fuel burned per hour at wide open throttle, this is rule of thumb. As you have found out, that old fifty does not play by the rules. Other than running the correct prop, (and that may be hard to find) I know of no way to make it better. Because of the way your engine mounts to the transom, A tilt & trim would be difficult without custom fabrication. That engine is just not worth that.

 

[Chinewalker]

Re: 50hp Sea Horse Gas Guzzler

Hi Stephen,<br /> Changing the prop will only help (marginally) if the prop you currently have is incorrect for the boat and load you're pushing. Those motors by their very nature are VERY thirsty beasts. If you must improve your mileage, find a newer motor. The 1980s vintage loop-charged Johnrude twins in the 50-60hp range do alright on fuel, as do the loop-charged triples in the 60-75hp range. This vintage and style of motor is also more conducive to adding power trim...<br />- Scott

 

[rodbolt]

Re: 50hp Sea Horse Gas Guzzler

that 58 50 hp was a solid motor that ran well but fuel economy was never mentioned. course gas was almost free then so who cared. we skied with one when i was young and 12 gallons would not make an hour. that motor is and was thirsty.<br /> good luck and keep posting

 

[gferail]

Re: 50hp Sea Horse Gas Guzzler

It was wishful thinking about the tilt and trim but I thought I would ask. I also found a free spare engine I was going to use for spare parts that is also in good shape and runs. For now I guess I will have to suck up the cost of fuel for a while. This is my first boat that I have owned and I did not think I would enjoy it so much. But I do see a new boat on the horizon. Thank you all for the advise.

 

[rolmops]

Re: 50hp Sea Horse Gas Guzzler

the fat fifties are nice engines and they make very respectable anchors.

 

[byordy]

Re: 50hp Sea Horse Gas Guzzler

I'm going from distant memory here, but maybe this will renew a memory for one of the pro's. There was a mod for the old fiftys that replaced the reed cage with one from an early sixties 60 or 75 OMC motor. The early "flat" reed cages used in the "fat fifty" were very inefficient, while the newer "tapered" reed cage is much better. As I remember some grinding of the replacement reed cage was required, but other that that it was pretty much bolt on. Seemed to reduce fuel usage a lot and possibly improved performance some.<br />Hope this helps.

 

[rwise]

Re: 50hp Sea Horse Gas Guzzler

Stephen<br />I have the same engine (evinrude) and the origanal manual that came with it. In the manual it states to use WOT to get on plain then back out to 3/4 throtle. This is the point where the carb is just starting to open. You will loose about 3mph on top end but gain gas mialage!<br />Richard