What shaft size?

[schinkehank]

 

[racerone]

I would say that 20" is LONGSHAFT.--------25" is an EXTRA LONGSHAFT.-----The boat shown will likely work with a 20" motor.-------But it looks like there is some work to be done before you can hang a motor on that transom.

 

[schinkehank]

I would say that 20" is LONGSHAFT.--------25" is an EXTRA LONGSHAFT.-----The boat shown will likely work with a 20" motor.-------But it looks like there is some work to be done before you can hang a motor on that transom.

Yes, lots of work!! I just want to keep an eye out for a “deal”. The original outboard has a 20” shaft but the extra length of the transom threw me off.

 

[Sea Rider]

That transom heigth is between a 20 and a 25 motor shaft. A 20 shaft will surely sit too high on transom and achieve prop aeration issues, In that case will need to modify/chop its heigth accordingly. Only a water test will confirm that...

Happy Boating​

 

[schinkehank]

That transom heigth is between a 20 and a 25 motor shaft. A 20 shaft will surely sit too high on transom and achieve prop aeration issues, In that case will need to modify/chop its heigth accordingly. Only a water test will confirm that...

Happy Boating​

Well, it needs a metric ton of work..if modification is required, I could probably raise the transom a couple inches to get the proper height for a 25” shaft. I’d be wary of lowering it, I plan on using it for a bay boat so I’d like it to be taller. It’s a sea Nymph, I wouldn’t think such a popular hull manufacturer would make such a odd size transom.

 

[Sea Rider]

It’s a sea Nymph, I wouldn’t think such a popular hull manufacturer would make such a odd size transom.

Have seen unbeliable odd transom heights in many boats as to make a perfect match with short or long shaft motors, in such cases a transom mod was needed to perform well. Luckily count with a transom techie that can modify whatever floats powered with an OB...

Happy Boating​

 

[racerone]

Well some mounting brackets ( on motors ) are drilled to let you set a 25 " motor at the " perfect " height on a 22" transom.

 

[JimS123]

The distance from the top of the transom mount to the AV plate on a long shaft motor is 22" for most motors. The Sea Nymph in the photo is typical of how most manufacturers build transoms for long shaft motors.

Although we all recognize 15, 20 and 25" motor designations, the transom dimensions are typically 1-2" higher.

If the motor used on that boat has the typical 5 hole transom bracket, it can probably be mounted up in the 2nd or 3rd hole to achieve better performance. If an extra long shaft motor is installed, even in its highest position it will be too deep in the water.

 

[roscoe]

what is with the 2 piece transom?

Looks like someone already added 5.5" to the original transom.

Model and year?
HP rating?
Your intended HP?
I would be very hesitant to add any additional height.

Photo of entire transom please.

 

[schinkehank]

what is with the 2 piece transom?

Looks like someone already added 5.5" to the original transom.

Model and year?
HP rating?
Your intended HP?
I would be very hesitant to add any additional height.

Photo of entire transom please.

That is a strap across the back 5.5” from the top.
Year:1984
Model:ss-175
HP rating: 100
Intended HP:

 

[roscoe]

see.... now

 

[Faztbullet]

It had a Merc Inline on it originally....most likely a 20"

 

[schinkehank]

It had a Merc Inline on it originally....most likely a 20"

Correct