Evinrude 1970 115hp on 18ft Starcraft aluminum

[farmuse]

I need to know where to start on prop selection for this 115 motor on my 18ft 1977 Starcraft Cheiftan cuddy cabin. The Evinrude seems strong and responsive I took of a 1972 Mercury 140 that would push it about 42 MPH. The clamp swiwel bracket broke on the Mercury and I cannot figure out how to get it off. Thanks for any help.

 

[Bob_VT]

Re: Evinrude 1970 115hp on 18ft Starcraft aluminum

17" pitch will serve you just fine. Make sure the motor is mounted on the 2nd hole from the top and have fun.

 

[farmuse]

Re: Evinrude 1970 115hp on 18ft Starcraft aluminum

Thanks Bob_vt

I had a 19 on the Merc but had no Idea what to use when dropping 25hp. When you say second hole from the top are you reffering to the pin for tilt?

It has hydraulic cylinders on it for tilt and trim but the guy I got the motor from did not have the hydraulic pump. I am looking for one now.

 

[Bob_VT]

Re: Evinrude 1970 115hp on 18ft Starcraft aluminum

No I am talking about the engine mount to the transom holes. There are 4 holes to choose from on the top of the mount and use the second hole from the top.

I think a 19 would not give you the optimum performance and you will not reach WOT rpms ......... it would be slightly lugging the motor.

My V-4 spins up to 5500 rpm's with a 17" prop and I really would even like to see 5800. If I went with a 19 pitch I would see less than 5500........so I am happy where I am at on my Starcraft SS......... mine is a 16' and ezmobee has a 19' with a v-4 running a 17" also.

 

[Bob_VT]

Re: Evinrude 1970 115hp on 18ft Starcraft aluminum

I think the motor you are looking for is available on ebay but I think on that model year ......... it is for tilt only and not trim.

 

[farmuse]

Re: Evinrude 1970 115hp on 18ft Starcraft aluminum

There are only one mounting hole on on each side the transom motor bracket on my motor, they are 9/16 inch holes. My boat has to be drilled for those. I just replaced the wooden part of the transom so that is no biggie. Are you concerned about the height of the cavitation plate in relation to the keel of the boat?

 

[steelespike]

Re: Evinrude 1970 115hp on 18ft Starcraft aluminum

Generally the antivent plate ends up about an inch above the bottom.
It should be visable on plane.