Max Motor Ratings-newer motor, older boat

[tcthunder]

I just bought a 1969 Lund 18 foot aluminum fishing boat. Tiller style with 3 bench seats. It is rated for a 55hp motor. Have the max hp ratings ever gone up by year or generation of motor? Is there is a difference between tiller and console ratings?

Example: a 1950's-60's 35hp motor is considerably larger and heavier than those made these days. Can I use a 60hp-75hp if it is newer (say 1990's on up) and still be safe in terms of the max hp rating for my boat?

 

[Bifflefan]

Re: Max Motor Ratings-newer motor, older boat

The max HP rating is for a new or almost new transom. If the transom is mushy and you put on a larger HP engine you risk it tearing the boat apart. Of course that goes for a motor not over the max also.
I know there are guys that have went over with no issues, but I don't think your insurance company will cover it.

 

[5150abf]

Re: Max Motor Ratings-newer motor, older boat

HP ratings have little or nothing to do with weight, it is the torsional force the engine puts on the transom, 55 is 55 no matter the year, they didi change the way they measure hp but as far as the transom it doesn't matter.

Your transom is possibly 41 years old, make sure it is in good shape and rebuild if needed.

You might get by with a 60 since it is really close to the rating but a 75 is too much.

 

[JB]

Re: Max Motor Ratings-newer motor, older boat

Ratings for tiller steer are much lower (often half) than remote steer.

There is no reasonable excuse to overpower. Don't do it.

 

[Wee Hooker]

Re: Max Motor Ratings-newer motor, older boat

Agree with all stated here. Also note that 4 stroke motors can weigh allot more then their older 2 strok counterparts. Beyond that, big tiller stear motors will wear your arm down from prop/stearing torque. A 40 hp is as big a tiller engine as I want to fight. I'm running a 30 hp tiller on a 16' mirrocraft and wouldn't want anything bigger.

 

[tcthunder]

Re: Max Motor Ratings-newer motor, older boat

Thanks all! I figure anything below that 55hp rating is going to drive it just fine. Just that most motors I came across were 60+ with tiller. Didn't know how the rating worked. Picked up a '59 Johnson 35hp for nothing and we'll see how that works out. Now that is a huge, bulky motor!

 

[ChrisAG]

Re: Max Motor Ratings-newer motor, older boat

Picked up a '59 Johnson 35hp for nothing and we'll see how that works out. Now that is a huge, bulky motor!

It may be huge and bulky, but I doubt it weighs more than a modern engine of similar horsepower.