Engine size for 1986 13' Super Sport

[rdalton1]

We have a 1987 Yamaha 40hp two stroke 20" shaft engine that we can't get parts for and want to upgrade to a newer model.  I can't find the optimum size for our 1986 13' Supersport.  Would a 4 stroke 20" shaft in a newer Yamaha be too heavy?  

[CaptBrett]

Hi Capt, 

Your boat is rated for a 40 H.P.  I am in the middle of a complete refit of 1982 15' Sport, which is rated for a 70 H.P. 

I am going to max it out with a 70.

Here is the motor I would put on your boat: https://yamahaoutboards.com/en-us/home/outboards/115-50-hp/40-30.

or

https://www.mercurymarine.com/en/us/engines/outboard/fourstroke/30-60hp/

I have always been a huge fan of MERC.  But they do not make a 70, so I am going with the yahmaha.  

Let me know what you decide.