Do you Know?

First of all let me say i know nothing about outboard boat motors. These are just a couple of general questions.

I just bought a 1976 14 foot fiberglass tri-hull fishing boat...after my purchace the guy who sold it to me said he had the original motor for the boat at a friends house...A Johnson 150HP outboard. Seems a little too big for a 14 boat. I guessing it is around 60-75HP. It has been sitting in a garage for the last 15 years. The motor was orginally used for the 30 year old boat.

Questin one...

1. Orginally the motor was wired into a steering wheel. Now there is nothing to wire it to. I know i can buy a kit to hook it up but is there a way to rig it so it can be operated at the motor?

2. Is it even going to be worth looking into the motor? Is it too old to mess with? What would the best thing to do in order for me to see if it is still operational?

 

Hello,

My experience with larger outboards is limited but I think it is safe to say it (150hp) could not be fitted with tiller arm steering. That also is a whole lot of motor on a 14' boat.

The boat would have to really be designed & built sturdily to handle the stresses imposed from such a motor. It could tear the transom right off the boat.

Depending on the boats intened purpose you may want to consider a smaller motor. I was quite happy with a 9.9hp on my 14'4" aluminum skiff I used for a whole season in SE Alaska. That would be somewhat small for a trihull glass boat. I would think that a 25-40hp would get you up on plane and be alot more economical to run than the 150hp.

Now if your pulling skiers or into speed and the boat can handle the power you might be A OK.

Smaller outboards are tested (at least here abouts) by putting them in a 55gal barrel full of H2O. Don't know if that would be feasible with a large motor though.

Hope all works out well for you.

I'm sure more knowledgeable folks will give better input soon.

Take care.

TGoz

 

Thanks for your input

Thanks for the suggetions and warnings. I was thinking that a 10-50HP motor would be perfect on the boat...i wonder if i could trade someone who knows how to work on motors for a smaller working outboard?

 

Johnson is a good motor. If it is in good shape you might make a nice trade.

The 9.9hp (2-stroke Nissan) I used would get me approx. 15.5 kts. if running with a light load. I usually ran at 8kts., just up on plane, which is the most economical speed.In remote AK where I purchesd the outboard it cost $1600 US. One in the lower fortyeight should be somewhat less.

Your boat is probably a good bit heavier than an aluminum skiff of the same size. If being used just for getting around fishing and camping and such, I would think 25hp would be ideal. Enough to get on plane and a little extra. I would go with a 25hp 4-stroke if I could afford it. Though heavier and more $$$ initially, they are quit & convient. Oil for 2-strokes is expensive and a pain to mix.

Take care.

TGoz

 

2 & 4 Stroke

Yeah i have been doing some research on 2 & 4 stroke engines...they both seem to have their own pro's and con's ....thanks for the advise..do you know any tricks or tips on how to get the old motor tested.

Do i need to change the plug(s), clean the carbs? Any ideas on how to get it fired-up to see how it runs before i invest money into it?

 

I'm no mechanic but changing the plugs & cleaning the carbs would definetly be needed. Some light lubricant into the open plug holes would be a good idea. Crank it with the plug wires off before fireing it up to move the lubricant around.. A lower unit oil change would also be needed.

Hook up the fuel, connect the starter to a battery, and hook up a way (check with an outboard dealer) to supply water to the coolant intake. The motor will need to be secureily mounted to a stand. I would not over rev. I'd also thoroughly flush the fuel lines & gearcase prior to running it.

Be VERY CAUTIOUS of the expossed prop as it is potentially lethal! An older engine might have other issues you may have to deal with.


TGoz

 

One more thing, when you fire the motor up, make sure the coolant is flowing/ pumping properly. If it is not, it will sieze up real quick.

TGoz

 

150 horses 14 footer boat

Get the flushing kit rubber piece that will enable you to connect a hose to supply water to the water pump/coolant suction, this will enable you to flush the engine without the water drum.150 horses is way too big unless your boat design is something like a Boston Whaler centre console. I used to own one 16 footer with 140 horses Suzuki.Real nice to run around.Fuel consumption is just a bit more compared to 70 horses,if your boat is heavy, might even be better than having 40 horses. If you are thrill seeker..that 150 horses is lot more thrill than 40 or 70 horses engine. I had used all this class of engine before. Two stroke engine is noisy if compared to four stroke engine.150 horses can be hand till but even at my place, only smuggler hand till those big horses engine.Had tried it once, it is a beast.Get a helm that push a cable for steering control type.The steel cable and pulley type is quite messy unless you want to race and need real fast response.

The type I'm talking about.

 

If you can get it for a song, consider buying it for another boat.

Just compression test it first. Actual readings don't matter as much as similar readings between cylinders. What do you say guys...less than 5% variability? Lots of old Johnsons still in service. If its cheap and compression is good, you will not get hurt.

Mike

 

For the cost of the parts if she runs you'll probably want to look at replacing anything rubber, fuel lines water pump impeller etc.

 

That engine sitting for 15 years..... will likely be a money pit and way too big for the boat. Sell it, get a 30 - 40 HP engine and have fun.