Will this motor power this boat?

[jrtredo]

Hello-
I just purchased a 1991 alumicraft trophy 19' bpat. the boat needs some work and it has an older (prob 1960's) 115 hp johnson outboard on it. I have a nice 55hp outboard that i would like to put on this boat. The boats weight is listed at 2000lbs the 55 is currently on my old trihull. Would this motor be too underpowered for pushing this boat?

thanks

 

[jay_merrill]

Re: Will this motor power this boat?

I would say that a 55hp motor on a 2,000 pound, 19 foot boat is going to result in performance that you probably won't be happy with. You will also work the motor pretty hard and will have to go with a very low pitch prop, which will result in high fuel consumption.

If the other motor is a 115 hp Johnson, it is at least a 1969 model, as far as I know. That would mean that it might be the old, distributor/amplifier ignition setup and hydroelectric shift. OMC didn't make a 115 again until 1973 and that motor has Magneto CD ignition and a hydro-mechanical shift, which is a much better arrangement, for the most part.

Look for a model number of the 115 on the transom bracket and post it here. Once we know what it is, we can better advise you on the motor's potential and value. As long as it is not a "junker," it just might turn out to be a decent motor, that will be much better suited to your boat. Just as a "fer instance." I have a 1972 Johnson 65hp motor that I love - its reliable, economical and perfect for my needs.



???

 

[kaferhaus]

Re: Will this motor power this boat?

And "some" of the older motors are near bullet proof. Down this way you'll see hundreds of old Johnnyrudes 40-70HP twins from about the mid 70s to mid 80s humming along every weekend... and most are used exclusively in salt/brackish water.. Most parts are still available new and those that aren't are supplied by the many OB bone yards in the area.

Plenty of the V-4s of the same vintage running too.

Many older Mercury's of that vintage still running too but I've never been partial to them as even the 50 is a inline 4cyl... too many carbs to work on and they're comparatively heavy and tall.... but a good running merc of that vintage will scream.... might just be me but I think some models were "underated". Some of those 4cyl 50s seemed like they were putting out closer to 60hp than 50.

I've got a 82 50HP Johnson on one of my tin boats that I bought used 10yrs ago... the man I bought it from was retired and ran that engine almost everyday on his morning fishing trips. It looked brand new (still does) but the compression was only 115... new they made about 140psi... so it was not worn out but well worn none the less. I checked it again maybe 5yrs ago and it was 105.... checked it at the beginning of this season and it was right around 90....still cranks real easy and although it has to be down on power I can't really tell it. I may get a few more years out of it or it may die this sping.

I'm very tempted to rebuild it once it does... about $400 in parts and $125 in machine shop time.. and of course my labor. Even at that... these engines can usually be found in decent shape for 4-$500... however I KNOW this one...never a bit of trouble with it... it's gotten new gear oil every year and a new impeller every other year, new water pump kit 5years ago. I think I've replaced the plugs twice.

 

[jeff_smith_0423]

Re: Will this motor power this boat?

Many older Mercury's of that vintage still running too but I've never been partial to them as even the 50 is a inline 4cyl... too many carbs to work on and they're comparatively heavy and tall.... but a good running merc of that vintage will scream.... might just be me but I think some models were "underated". Some of those 4cyl 50s seemed like they were putting out closer to 60hp than 50.

Gee, there are only two...

The 55 isn't going to be enough. Pursue repairing your 115 if it's of decent vintage.

 

[jrtredo]

Re: Will this motor power this boat?

Thanks for the responses. Thats what I was afraid of. I need to find a trailer before I can bring it home. Once I do I will post the model number and hopefully the motor isnt junk.

 

[kenmyfam]

Re: Will this motor power this boat?

You will not be happy with a 55hp on that outfit in my opinion.