Hal Kelly Jupiter 10

[FullSendMarine]

Hi All, from Australia

I am planning out my next build, from a set of original Hal Kelly plans "Jupiter 10ft". I have a few questions;

I prefer working with composites, is there any reason I couldn't build this from a fiberglass foam core laminate. 4mm foam core with 1200gsm of glass each side for the main stringers , and 400gsm for the batons etc will be much stronger and lighter and never rot. If it ends up lighter than the original, is it worth thinking about some adjustable ballast for the nose, to help the running attitude?

I have a 3cyl Mercury 25hp, in Australia it was labeled as a Force 25, in the US it was a Lightning 25... only weighs 80-90ish pounds, and is the only 3cyl 25HP as far as I am aware. I am looking at upgrading the Carburetor and reed block setup as it looks very restrictive an I feel like it would be a good candidate for modification . Also will install a low water pickup so I can run high. Do you guys prefer transom pickup or nose low water for that purpose? the gearcase is pretty skinny so I'm not confident a bobs marine nose cone kit will fit,

I am a little lost on prop setup to try, I was looking at Hill Marine signature round ear choppers (16P) and the Cleaver (16P), but I don't have a lot of experience running a surfaced propeller, my understanding is you don't want too much prop lift for a hydro as the hull does it for you? That being the case, a cleaver would probably work better?

Sorry a lot of questions I know, it's just such a different setup to my 20ft deep-vee!

[DeanFHobart]

Hi All, from Australia

I am planning out my next build, from a set of original Hal Kelly plans "Jupiter 10ft". I have a few questions;

I prefer working with composites, is there any reason I couldn't build this from a fiberglass foam core laminate. 4mm foam core with 1200gsm of glass each side for the main stringers , and 400gsm for the batons etc will be much stronger and lighter and never rot. If it ends up lighter than the original, is it worth thinking about some adjustable ballast for the nose, to help the running attitude?

I have a 3cyl Mercury 25hp, in Australia it was labeled as a Force 25, in the US it was a Lightning 25... only weighs 80-90ish pounds, and is the only 3cyl 25HP as far as I am aware. I am looking at upgrading the Carburetor and reed block setup as it looks very restrictive an I feel like it would be a good candidate for modification . Also will install a low water pickup so I can run high. Do you guys prefer transom pickup or nose low water for that purpose? the gearcase is pretty skinny so I'm not confident a bobs marine nose cone kit will fit,

I am a little lost on prop setup to try, I was looking at Hill Marine signature round ear choppers (16P) and the Cleaver (16P), but I don't have a lot of experience running a surfaced propeller, my understanding is you don't want too much prop lift for a hydro as the hull does it for you? That being the case, a cleaver would probably work better?

Sorry a lot of questions I know, it's just such a different setup to my 20ft deep-vee!

Hello Full Send Marine,

If you are comfortable with composite materials… go for it…If it works great, if not, you could always build an original wood version. I would be interested is seeing how you would build it with the materials mentioned. What type of resin adhesive and fasteners are you planning to use… and would you be using some vacuum bagging also?

As far as the motor goes…. I’m assuming it has a longer tower housing than a ‘racing’ type tower housing. And also the issue with the fatter gear case. Is there any chance that you could adapt the power head to a shorter style racing tower housing with a streamlined racing gear case?… I would guess that prop choices would be easier. You mentioned Ron Hill… He has a lot of experience with all of this and he can help you with all of these issues. Give him a call and I’m sure he will be glad to help you. His phone number is available on his web site which is: boatracingfacts.com.

Good luck on your project. It would be interesting to see photos of your progress during your project.

[bh/]

If you are going to put all that effort into building a new Jupiter, I would advise building the 2nd Ed version, the one with the extended after plane, ie; ~10" longer. It handles much better. Also best not to focus too much on motor mods until the boat is near completed.