Motor size for 12' Starcraft

[Yakfish]

Hi,

I need to replace my 1969 Evenrude 18 hp motor on my alum 12' Starcraft boat. I am not sure what the recomended HP is so I wanted to get some feed back. I would like to buy a Honda 4 stroke but am not sure what size to get. I run the boat in Puget Sound so speed is desirable. The weight difference between the 9.9 and the 15 and 20 HP is not that different so I am thinking of going for the 20 HP in case I need to speed to safety.

Thank you,

Thomas

 

[5150abf]

Re: Motor size for 12' Starcraft

Welcome to iboats.

20 horse on a 12' tinny is ALOT, I would geuss the boat is rated for 10-15.

A 15 should run as well or better on the boat because the 69 was rated at the drive shaft where a newer engine is rated at the prop, so your 69 18 horse would be a 10-12 horse now.

Maybe someone knows for sure but I would stay with no more than 15.

 

[Yakfish]

Re: Motor size for 12' Starcraft

I found the Boat rating plaque and is states the max horse poweris 18. The 15 and 20 HP Honda 4 strokes are the same motoer and weightthe same. As far as I know only differ in carberation. So go 15 or 20? I also considered the 9.9 but it only is a few pounds lighter.

Thomas

 

[Huron Angler]

Re: Motor size for 12' Starcraft

The weight of the outbord is not the only factor to consider when deciding how big is too big. The force of the forward thrust stresses the transom and that is the primary concern. If you do want to throw an excessively powered motor on there I would suggest checking that transom carefully and maybe reinforcing it to add strength. Like you said you will be in some big water in the sound so I'd be concerned about the transom integrity.

How many knees does the transom have pushing back on the transom? I would guess that it has three but my 12' only has one so it is rated for only 7.5hp. If you have three that helps but depending on the condition of your transom wood it may need replaced.

Do you have pictures of the boat?