Length Mercury 8hp longshaft.

[davidpbo]

Is anyone able to tell me the length from transom bracket to centre of prop of a 1989 Longshaft. I am sitting on one on the boat but it is in a well and difficult to measure.

 

[VicS]

Is anyone able to tell me the length from transom bracket to centre of prop of a 1989 Longshaft. I am sitting on one on the boat but it is in a well and difficult to measure.

not to centre of pro but if you measure from the transom top to the anti-ventilation plate above the prop a short shft will be a little over 15". A long shaft will be a little over 20"

see:-
http://smalloutboards.com/shaft.htm

So about 26 or 27" give or take. My 6hp 'rude is 27"

 

[davidpbo]

Thanks Vic, Back home now. An electric start 8hp Honda was advertised that I was interested in. It was stated as being an extra long shaft 25".

Would this be likely to push my boat (1900kgs displacement sailing cruiser) along with the same power as my 8hp mercury 2 stroke ?

Don't know at present about prop or gearing etc.

 

[Lakesailor]

Plenty on Windermere (unless you are moving to the coast). Only the wind to overcome.
25" is the measurement as Vic said down to the cavitation plate.
That is pretty long as outboard legs go, bound to be good enough. I have found 4 strokes to have more grunt compared to 2 strokes, and to be quieter.

 

[davidpbo]

We have taken the boat to more tidal waters sometimes so don't want any less grunt than we have. I very much like the idea of electric start having had a torn rotator cuff and undiagnosed back problems last year but want manual as well. Also like the idea of quieter, less smelly and better fuel consumption.

 

[davidpbo]

Sorry to resurrect this thread after a while and thanks for the input, it appears that length of shaft is quoted from top of transom to anti cavitation plate is that correct and the same for all outboards?

The reason why I ask is that now re-united with my workshop manual it quotes 3 lengths.
Short 15" 38cm, Long 20" 51cm, Extra Long 25" 63.5 cm. but it does not say where the measurement is between.

From my perception of the length of the shaft it would seem to be to the anti cavitation plate.

 

[VicS]

Sorry to resurrect this thread after a while and thanks for the input, it appears that length of shaft is quoted from top of transom to anti cavitation plate is that correct and the same for all outboards?

The reason why I ask is that now re-united with my workshop manual it quotes 3 lengths.
Short 15" 38cm, Long 20" 51cm, Extra Long 25" 63.5 cm. but it does not say where the measurement is between.

From my perception of the length of the shaft it would seem to be to the anti cavitation plate.

Actual measurement down to the anti-ventilation plate is usually about 1 to 2" more that the 15/ 20/ 25" quoted shaft lengths.

In this example for a 15 " motor it's 16" from transom top to AV plate

Honda ITYWF quote the actual dimension eg 561mm for a long shaft.