Do I actually need water-cooling for my Type J gearbox?

Mine is absent, and apparently most are, as they corroded away.

Gentle river use is not an issue, hard estuary use might be, check top of gearbox with a hand, if it's not too hot to rest hand on it for a while, it's OK, if it's F hot, probably not...

Excellent.  Ours is leaking water from underneath and we plan to bypass it by installing new hoses[1] from the weed-trap to the oil-cooler.

As you say, we'll just have to initially keep an eye (or a hand) out for overheating.

Cheers!  

Footnote
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1. Proper vacuum hoses which won't collapse -- not garden hoses which do collapse!

Hi, to all members of BOC i am a new member, Frodo is the name. I bypast the gearbox with the cooling water and went straight to the jabsco in my B25 Sea Tiger engine last year. I think it says in the gearbox manual it is only the 1600cc Seatiger engine that the raw water goes through the rear gearbox mounting.

Hi Frodo, we're looking forward to your intro post...

Yep, my Seat Tiger has the rear mount piping, dunno what it does though?  

Sounds about right... no hoses going to Carli's J-type gearbox, but the Sea Panther has less BHP. More torque though....  

Ah, Torque.

Is that what makes all the noise and smoke then?    

I'll keep my 'High power' instead in that case, and leave you your 'Superior hill climbing ability'

Mind you, might be handy with this weeks weather forecast  

Hi Guys, a bit of a late reply but I just had to add my tuppence worth about cooling the "J" type gear box. It would seem I must have the only non leaking and still working one in the BOA  ???. I have just sent a reply to Frodo regarding overheating coils!! maybe of interest to some of the other members.
Anyway my gearbox overheated due to excessive engine temperature and heat being transferred to the gearbox even though the gearbox was fully cooled by the water around it !!!!
The result was all the bearings were knocked out and had to be replaced!!!! The corect oil was in the gearbox at the time.

Seadog

The nice thing about non-tidal use is the low speeds are so gentle on the mechanicals.