2 Boats Only 1 Outboard

[Sportdog7]

Hope you can tell me if I'm expecting too much from my 1985 Johnson 15hp. tiller I have 2 boats that I would like to use this motor on, (The motor runs great) a 15ft. fiberglass Lund "Old guide boat with a tri-hull design, and a 15 ft. Starcraft deep-V that was a runabout but I modified it for duck hunting by removing a lot of the top cowling and the remote steering and cables. The 15 was on the Lund all the time until last fall. It would plane out this boat but only if I was running solo, I've had this boat motor combo for 15yrs. I was going to buy a bigger motor but a friend looked at my prop it was a 10 pitch and said I should try a 10 X 7 pitch prop he felt it would do a adequate job getting either boat up on plane. Please understand I'm not expecting this prop to turn either boat into a rocket! I'm thinking the total weight inc. hull & all passengers & gear to be about 1100lbs.. Should I order the prop? Or is there a better prop selection? I really don't want to buy a bigger motor I just don't have extra cash to do so, your advice would be welcome....Thanks

 

[Sportdog7]

Re: 2 Boats Only 1 Outboard

Have I left anything out in my description that's making it difficult to give me your ideas? I know its a small motor but its all I can afford in these economic times! Will going to a 7 pitch prop from the 10 pitch that's on it allow me to get these boats on plane? As I said the motor has a tough time getting the 15ft. Lund glass boat on plane with only 1 person.

 

[SparkieBoat]

Re: 2 Boats Only 1 Outboard

you can test with different props if you want to but a 15 HP motor is just plain under powered for either boat, I would have either a 30 or 40 HP motor on either boat, should plane on a full load no problem then. you could probably sell your 15 for about the same price as a good used 30 or 40 tiller steer. I would think a 25 HP motor would be absolute minimum for either boat.

 

[Sportdog7]

Re: 2 Boats Only 1 Outboard

Thanks for your answer SparkieBoat, I wish that a bigger motor were an option for me its not. I know its underpowered but its what I have to work with, It is close to putting the two boats on plane now with the 10 pitch prop. I sure would hope that a 90.00 7 pitch prop would be the answer as far as getting the boat on plane. I don't expect it to be fast, I just don't want to lug the engine.

 

[lncoop]

Re: 2 Boats Only 1 Outboard

I don't have an answer for you, but if you want to experiment you might consider buying a prop from your local dealer. May cost a little more, but most dealers will take a prop back provided they can still sell it. That way if it doesn't work out you're not stuck with a prop you can't use. I think most online retailers have the "if it gets wet it's yours" policy.

 

[Sportdog7]

Re: 2 Boats Only 1 Outboard

Guy's I put the 10 X 7 prop on the Tri-hull its the heaviest of the 2 and took my wife & our 100lb lab for a boat ride. It performed GREAT I was on plane in no time (My guess is I was on plane from a stop within 40yds) I just wish I would have brought my GPS to get a real idea of top speed. My best guess is around 20mph, I don't have a tach but it didn't seem to be over revving. Yes I bought the prop (Michigan 10 X 7) from a marina I've dealt with before and your right Incoop he said if it doesn't work he would allow me to return it. I sure am happy I tried this fix before I gave up, nice when something works!

 

[steelespike]

Re: 2 Boats Only 1 Outboard

The 15 likes to revfreely and is rated for 7,000.Comes with the same prop as the 9.9.
I'd like to see it on a tach but you are pushing a real tub and a house full.

 

[Sportdog7]

Re: 2 Boats Only 1 Outboard

I know what you mean! I'm quite sure its within normal limits, if it would have planed out to fast I would have been worried it might be over revving. I've had this rig for quite a few years I think its gonna be fine but if I can I'll try to get a reading.

 

[SparkieBoat]

Re: 2 Boats Only 1 Outboard

I am glad you are happy with your performance..I would lose my mind if I had to go 20 MPH top speed..LOL why is a larger motor not an option? you originally listed that you were going to get a larger motor. a 25 just is not that heavy. ..but if you are happy with what you have I guess your fine.

 

[Sportdog7]

Re: 2 Boats Only 1 Outboard

SparkieBoat, I was looking into the possibility of a 25hp. and yes I have a full time job. It's the cost & the crappy economy that made me look for alternatives. I know 20mph. seems slow (It is compared to many rigs) But its a lot faster than this same boat & motor combo was when the 10 pitch prop was used!

 

[Sportdog7]

Re: 2 Boats Only 1 Outboard

Just a update. I took the 15ft. V-bottom that I converted (Was a runabout) for a test run with the 15hp.. Myself my son and my dog, my guess is around 800lbs inc. gear. I was totally impressed!! Again I was without my GPS but it seemed to have more top speed than the Lund Tri-hull Guide Boat it went right up on plane, I'm so happy I tried a different prop, it has saved me a lot of money over the cost of buying a bigger motor.

 

[SparkieBoat]

Re: 2 Boats Only 1 Outboard

again..you could probably sell your 15 and get a good used 25 for about the same amount, making your $$$ = 0 . but if you are happy with your set up I am glad for you.

 

[Sportdog7]

Re: 2 Boats Only 1 Outboard

As soon as I find my GPS I'll see just how fast I'm going with the 15, but I think I'll stick with this set up. I'm able to quickly get up on plane with a good size load no matter the boat I choose to use, Its a huge improvement over what this motor offered me before the prop change.