Repowering my old 16ft aluminum boat thinking of going 4 stroke but have a question

[canadianboater86]

Hi All i have a 1976 springBok 16 ft boat that’s similar to the starcraft ss that has a 76 johnson 85 v that unfortunately doesnt have power tilt & trim and i hear it can be hard to find the factory unit . I’ve looked at the power jacks like bob’s or panther but there $1600-2700 here in Canada . so unless i can find a used jack plate it doesn’t make sense to spend that much . I’m thinking of repowering with either a 2 stroke from the 90s like a yamaha or johnson or a early 4 stroke from early to mid 2000s

My question is if i go 4 stroke do i go up in power from my original 85hp johnson or go down because of weight. Would a 60hp 4 stroke be enough for a mostly fishing type boat

this is a project boat and i’m redoing the floor with 1/8 aluminum checker plate and redoing the transom sealed with west system epoxy so that will be able to handle the 4stroke

 

[Ifishmuskie2]

Was the original engine hp rated at crank or prop shaft?

 

[racerone]

A 1976 motor would not be prop rated.----Your location in Ontario?

 

[airshot]

Buying a used 4 stroke could be a big gamble, the reason being is they are " very expensive to work on" where two strokes are pretty cheap and simple. I am an old two stroke fan...I have a 16' Sylvan side console with a 40 hp two stroke that dies 31 mph. Moving up to a 60 up four stroke would gain me about 5 mph and 6K or more in cash. Would need to save an awful lot of gas to make up that 6K. Other than extra weight, the newer 4 strokes are pretty sweet, but used ones can be a gamble like anything used. Just so darn expensive to repair if something goes wrong.

 

[racerone]

And most shops are reluctant to do major repairs on 4 strokes.

 

[airshot]

My local dealers tell me that if a major problem arises under warranty, they just swap out a short it long block rather than actually tearing down the motor to make the repairs. Faster to swap out a short/ long block than the labor to tear down and rebuild a four stroke....