Tohatsu OB short or long shaft?

[patfarrell1949]

I have a (new to me) Tohatsu 6hp OB on my dinghy and am considering the purchase of a backup and slightly more horsepower motor. Question is how do I determine the shaft length...short or long? Model number is MFS6BS 3R4. Can anyone help please?
This is my first post here so hopefully I've placed my question on the correct forum...if not I'll appreciate the feedback.

[donradcliffe]

In most cases, the dinghy transoms are sized for short shaft outboards. A long shaft is intended for use with larger boats and slower speeds.

[belizesailor]

Most likely a short shaft, but just measure it to be sure. Here is an article explaining shaft length options and how to measure.

http://www.smalloutboards.com/shaft.htm

After you look at a few short vs long shaft OBs, it will become obvious.

[44'cruisingcat]

Measure the transom height on the dinghy, from the top to the keel. It's most likely around 15", which suits a short shaft.


If it's 19" - 20" a long shaft would be better.

[Reefmagnet]

You current motor is a short shaft 15" version going off your model number.

Sent from my SGP521 using Cruisers Sailing Forum mobile app

[patfarrell1949]

Thanks for the responses...you've confirmed for me the OB is a short shaft version.

[topcar]

The shaft length is measured from the inside of the transom mount down to the cavitation plate above the prop. The accepted short length for Johnson Evinrude etc is 15" but Tohatsu outboards are slightly different from most others... the Tohatsu is 17". This was the main reason why I have a Tohatsu 8hp on my 25 foot sloop... I get those extra 2" without having to have a long shaft outboard.
Also, It is worth investigating the power rating as many outboards can be economically uprated. For instance, the Tohatsu uses slightly larger carburettors to go from 6hp to 8hp to 9.9hp... identical otherwise.

[patfarrell1949]

Thanks again for the info...mine is on my dinghy so I guess that kind of makes it "short" automatically!