Long shaft to short shaft Mercury 1150 conversion?

[kungpaoshizi]

I've been looking around for info, but everyone seems to want to go from short shaft to long shaft..

I saw a post on here about a Mercury 800, it has the same midsection, different gears (to warrant a prop change), and a few slightly different components elsewhere.

Is there other models to consider as well that are compatible with a '77 1150, perhaps without a gear difference?
Is a short shaft even advisable for a 1150, or just a medium shaft because of speed differences or something?

 

[Mi duckdown]

Re: Long shaft to short shaft Mercury 1150 conversion?

It all depends on the BOAT height transom you have. 15" short, 20" long.

 

[matt167]

Re: Long shaft to short shaft Mercury 1150 conversion?

short shaft 6cyls do exist but not many. You could use a 65-85hp short shaft 4cyl midsection and other parts. Gear ratio is 2.3:1 for the 4 and 2.0:1 for the 6. It will never run full potential with the lower ratio. If you want 115hp on a 15" transom, get a jack plate

 

[Chris1956]

Re: Long shaft to short shaft Mercury 1150 conversion?

Kung, I had thought your transom was 20". There are not many boats rated for 115HP that have 15" transoms.

 

[kungpaoshizi]

Re: Long shaft to short shaft Mercury 1150 conversion?

Transom itself is 19"... Jack plate will definitely be the way to go, just wondered if I can achieve the same output with a <20" shaft

Btw, this is the ONLY printed information I can find on the boat... lol
http://boatspecs.iboats.com/Venture__Stallion__1986/bp/66b99896

 

[Chris1956]

Re: Long shaft to short shaft Mercury 1150 conversion?

If you hang a 15" shaft motor on that boat, you will not get on plane.....

 

[Faztbullet]

Re: Long shaft to short shaft Mercury 1150 conversion?

Kung the dealership I worked for in 1979 sold Venture bass boats and you need a standard 20" motor. That boat with a 4 "jack plate( 6" reversed) with a 20 Turbo ran in the high 40's -low 50's depending on load.