Out oard Conversions

[Thompy_04]

I have an old 1970 Johnson Seahorse 9.5 horsepower outboard and was wondering if I could get any more speed out of it. Its mounted on a 14' V-bottom boat and it won't plane AT ALL. Was wondering if I could get an engine upgrade and make it more of a 15, 20, or 25 horsepower. OR if these hydrofoils or trim tabs would get me more speed, or ability to plane better.

 

[Chinewalker]

Re: Out oard Conversions

Hi Thompy,<br /> If your 9.5hp is running properly, has a decent and properly matched propeller, then it should certainly plain off even a modestly loaded 14-footer. Those motors have a fair amount of spunk to them and should be able to get your going if all is well. I would start with compression check and go from there. Sounds like you're not even getting all 9.5 ponies to start with...<br /> One thing is for sure - you're not going to get anything more than 9.5hp out of that motor. <br />- Scott

 

[LubeDude]

Re: Out oard Conversions

Welcome to the forums Thompy_04:<br /><br />Chinewalker is right, you are shooting for the moon. What kind of a boat are we talking about? Aluminum, Glass, etc. If aluminum, you might have a chance of getting decent performance if the engine is as Chinewalker stated, "runnung right", if its an old heavy Glass boat, Dream on. There are plenty of old 25 HP engines out there that could just use a little TLC to make them a good engine.

 

[phatmanmike]

Re: Out oard Conversions

i heard lube dude say that the easiest way to get 100 horsepower from a car with 50 horsepower is to remove the radiator cap, and drive a nother car underneath it........ kinda applies to boats too,,, lube dude cracks me up <br /><br />but its true, these lil motors are usuall maxed when they came from wisconsin to start with....

 

[LubeDude]

Re: Out oard Conversions

Thanks Phatmanmike, Ill take that as a compliment. Im glad I can touch someones life, even if it is with just a laugh once in awhile.

 

[Thompy_04]

Re: Out oard Conversions

I have a aluminum boat, with a plywood floor, and 2 seats and I mounted a bow mount trolling motor on her. Don't know the weight, but she's not to heavy..... As for compression check, how would I go apon doing that, or what tool would I need. If the compression is bad, or low, what do I need to fix? Are the rings bad or what. Now for the hydrofoils, will they help at all, planing wise, and steering wise? Need all the info I can get. Just graduated high school, hehe... and bought a boat for some around the area fishing..... Thanks guys.

 

[Thompy_04]

Re: Out oard Conversions

One more thing, props.... What prop should I use if you can answer that. Its just a standard stock prop not dinged up or anything.... But if I were to get a new prop, which way should I go?

 

[Mercathode]

Re: Out oard Conversions

Thompy<br />Assuming your motor is running correctly, you may move some weight to the front ie gas tank. Some these smaller motors have a tough time breaking the bow over to plane. Those little 9.5 Johnson were small, light, but not a good base for performance mods.