1968 Starcraft Jupiter - Rebuild

[Jeepcollector91]

Re: 1968 Starcraft Jupiter - Rebuild

Glad to hear that the Jupiter is doing well. Did you get that 90 dialed in for best performance on the Jup?
What size prop (pitch & diameter) are you running?

 

[InMotion]

Re: 1968 Starcraft Jupiter - Rebuild

Glad to hear that the Jupiter is doing well. Did you get that 90 dialed in for best performance on the Jup?
What size prop (pitch & diameter) are you running?

Thanks man. 90 is running much better.... not perfect... but really pretty good. Hole shot is now terrific --- as a passenger, you have to hold on to stay in your seat! I think I am running a 13 3/4 x 17 on it. The 19 gave a higher top speed but caused the engine to rev to low --- which it doesn't like to do --- unless you were really into of course! Cruising around I much prefer the 17 pitch as well as for docking the boat.

Overall, I really like the opennes of the boat for the family and extended family... It'll be around for a while!

J.

 

[Jeepcollector91]

Re: 1968 Starcraft Jupiter - Rebuild

Thanks for the info. I was using a 13-3/8" x 17 stainless steel prop and was going to try a 13-3/8 x 19 but the '85 Johnson 115 began losing power before I could try other props. Low compression on one cylinder. I will rebuild it eventually, just don't have time right now.
I just bought a 1998 Evinrude 115 SPL for the Jup (came with a 1976 Winchester w/'95 Magic-Tilt trailer) and was still thinking of trying the 19 pitch on it but figured I would check with you first to see what worked out for you. I know the motors are 25hp apart but figure the info would send me in the right direction.

Thanks again.

 

[InMotion]

Re: 1968 Starcraft Jupiter - Rebuild

Thanks for the info. I was using a 13-3/8" x 17 stainless steel prop and was going to try a 13-3/8 x 19 but the '85 Johnson 115 began losing power before I could try other props. Low compression on one cylinder. I will rebuild it eventually, just don't have time right now.
I just bought a 1998 Evinrude 115 SPL for the Jup (came with a 1976 Winchester w/'95 Magic-Tilt trailer) and was still thinking of trying the 19 pitch on it but figured I would check with you first to see what worked out for you. I know the motors are 25hp apart but figure the info would send me in the right direction.


Thanks again.

No prob.... I would think the 19 pitch would work great with that new 115 spl. The 17 pitch prolly with the light Jup would likely result in an over rev situation. Even with the "just" the 90... it revs at what sounds about wot revs... I would not want to be reving any higher. If it were able to push it any faster, my 90 would be in an over rev situation. I am running around 40 to 41 mph gps'd.

With the your newer 115, that Jup will absolutely fly! As a result, I suspect the 19 pitch would be the right match with speed and rev's. That's a big motor for that boat... but if you don't go crazy, it should be just fine. Even with my 90 on it, the Jup feels stable and solid. When you want the power, it goes like stink.

All the best!

Jim

 

[InMotion]

Re: 1968 Starcraft Jupiter - Rebuild

Ok fellas... little heads up here... this boat is going to get a bit of an interior update this spring as well as a newer motor and a bunch a nice new shiny bits!!!! So... stay tuned as a new back seat, removable table and other things get added from a bunch a parts and extra wood that I have lying around!!

Goal: reduce gas consumption by half, get a newer motor without paying a dime and add all the new interior mods for less than $20 bucks... lets see how it goes.

Note: Premium Gas here with oil is close to $8 a gallon!!! Sooooo.... lightening it up plus different motor is critical!

So, it will be coming back to the shop in the next few weeks!

Take care fellas,

Jim

 

[Jeepcollector91]

Re: 1968 Starcraft Jupiter - Rebuild

What are you thinking of getting and what HP? I am leaning toward the Yamaha F70 for my '66 Jupiter. Should be more than enough power for the lightweight 16' Jup.
My father has a Yamaha F115 on his much heavier 21' Carolina Skiff and can run around to all his offshore fishing spots and has never used more than 7 gallons for the day. Most days are less than 4 gallons.

The Yamaha F70 weighs in at 257-Lbs dry.

 

[InMotion]

Re: 1968 Starcraft Jupiter - Rebuild

JC --- looking to go much smaller actually... After 2 years of use, the Jupiter spends 90% of it's time going less than 15 mph! The other 10% of the time is with me driving when I am there, at planning speed --- just to unfoul the plugs from going so slow so often!!!

The Admiral and kids are at the lake for 6 - 7 weeks of the summer and they use it with my MIL and her 4 dogs to go around the lake and hang out in! So it gets a ton of use, but the 90 is complete over kill. So it is going to be either a late 90's triple 35 or a 40/50 hp Johnny. I have a line on a completely re-built 35.

Gonna replace the big 22 gal take up front with a 12 gal poly tank I have which between gas and tank will remove about 100lbs or so. So... trying to lighten the whole rig up for easier towing and waaaaaay less gas use from a smaller motor. With the tank up front and front passengers sitting soooo far forward, that Jupiter planes just about instantly. I have access to other boats with tons of hp for a speed fix!

So we will see how it goes.

 

[dozerII]

Re: 1968 Starcraft Jupiter - Rebuild

Boy there sure are a lot of changes going on around the Inmotions boat shed!!!

 

[barato2]

Re: 1968 Starcraft Jupiter - Rebuild

i like your plan but fear it may be going a bit too far. i'm no fan of driving around the water mindlessly pulling things (unless it's lures...:embarassed but suspect as your kids get older, they might think the idea of tubing etc is fun.

 

[InMotion]

Re: 1968 Starcraft Jupiter - Rebuild

i like your plan but fear it may be going a bit too far. i'm no fan of driving around the water mindlessly pulling things (unless it's lures...:embarassed but suspect as your kids get older, they might think the idea of tubing etc is fun.

Agreed.... but that's what the other boats are for!

 

[InMotion]

Ok.... pulled the big gas tank out of the front of the jup and did a bunch of little things like new rear cleats. Also got to polishing the new way the sides of the boat. Plan is to finish it up this coming weekend and install the newer motor I pickup tonight. Just pulling the tank and associated wood and bracing out made the front the trailer tongue light enough for me to lift with one arm vs requiring two people! Gas, tank, wood structure adds a lot of weight!

I will post up some pics next weekend of the polish/motor and if I remember a video of how the boat goes with the newer motor.

Have a great one fellas!

Jim

 

[InMotion]

Ok.... pulled the big gas tank out of the front of the jup and did a bunch of little things like new rear cleats. Also got to polishing the new way the sides of the boat. Plan is to finish it up this coming weekend and install the newer motor I pickup tonight. Just pulling the tank and associated wood and bracing out made the front the trailer tongue light enough for me to lift with one arm vs requiring two people! Gas, tank, wood structure adds a lot of weight!

I will post up some pics next weekend of the polish/motor and if I remember a video of how the boat goes with the newer motor.

Have a great one fellas!

Jim

 

[Jeepcollector91]

...and if I remember a video of how the boat goes with the newer motor.

[FONT=trebuchet ms, helvetica, sans-serif]Yea...a new video. I look forward to seeing the Jupiter in action.[/FONT]

 

[InMotion]

Ok... so 35 is terrifically smooth.... I decided to go mental and polish the entire boat, seal it, install the new motor and controls and re-setup the boat in a day! Not recommended unless you want to look tired the next day.... Polishing it that quickly does not come out as nice as I would have liked... but I only had one day available... so that was it!

I picked up a new prop this week... the one I had on was way to low of a pitch... boat accelerated great, but revved to high... so I picked up a 10x15 vs the 10x13 on it. Will install this weekend and see what it is like over the next couple of weeks of vacation time!

Overall, I really like the motor... obviously no where near the punch of the 90... but it absolutely sips gas and at $6+ a gallon for premium that IS important!!! It is amazingly quite as well.... accidentally tried to start it while it was running it is that quite. So good stuff all around. The Admiral so far is happy with the choice.

Have a great one fellas.

Jim

 

[Jeepcollector91]

[FONT=trebuchet ms, helvetica, sans-serif]So how is the Jupiter performing with the 35hp outboard?
Back when I first got my '66 Jup I had considered the very small Yamaha T25 High Thrust Four Stroke but since I already had the 1985 Johnson 115, I decided to go with that to save some money especially after seeing how well your Jupiter did with the 90hp. Of corse I didn't have the best of luck with the 115 when it lost power on its initial test run with the Jup[/FONT][FONT=trebuchet ms, helvetica, sans-serif] (low compression on lower right cylinder)[/FONT][FONT=trebuchet ms, helvetica, sans-serif]. I then ended up buying a 1998 Evinrude 115 SPL and it's a great motor but is extremely thirsty and I can't seem to control myself with the throttle. Just can't resist the "POWER" which really doesn't help with the fuel consumption.
So now I am thinking of going back to my original plan and trying out the 25hp.
Hope to see some videos soon of your Jupiter with the 35hp in action.
I'm sure you said somewhere already but what brand outboard did you go with? New or used? 2[/FONT][FONT=trebuchet ms, helvetica, sans-serif] or 4-[/FONT][FONT=trebuchet ms, helvetica, sans-serif]stroke? Kind of crazy that you go with a 90 and I just had to top that with a 115. Now you go with a 35 and I may actually have to take that to the other extreme with a tiny little 25. [/FONT]

 

[InMotion]

Hey jc.... Thanks for dropping by... Just on vacation and tested the new prop yesterday. Much improved!!! Runs fine. Tops out just below 30 mph. Cruises well in the low to mid 20's. No issue getting on plane with 4. It sips gas. I have yet to get the 6 gallon tank out of "F" range despite running all over the lake. As a rough guide the 90 would have drained at least 4 gallons! It is a very linear power delivery. The 90 was really punchy. Just howled when I gave it. But the 35 is great for what we are using it for. For those that are in need of speed I wouldn't recommend it. But after going 70 on a Seadoo all seems slow. Anyway, I like the fact that it is smooth, super quite and sips fuel. Keep us posted what you do!!!

 

[MNhunter1]

Great report! Gives me confidence that my 35hp Merc will serve the 15' Nova just fine. Hulls may vary a bit between the Jupiter and Nova, but I'd assume the weights would be similar, if not even a bit less for the Nova. I'm not worried about top end, but was a little curious as to if/how it would plane with 4 adults on board.

 

[InMotion]

Hey Guys... got an actual update here!

So, when the boat was not on the trailer and in the water, getting the boat cover to shed water properly and not pool up has been a bit tricky. The cover wants to pull up when the wind blows as well. So here is my solution that actually works!




What I did was use two pieces of 8' long PEX tubing and 2 bungee cords cut in half.... plus some scrap wood and screws



Beside the boat on either side I built two little stands out of wood as test examples (to be made better next week) --- had a limited set of tools this past week!


The two pieces of PEX are linked together using a piece of rope and two screws. Also, there is a piece of rope that hooks to the grab handle using the hook from the bungie cords.


On the outside under the gunwales I added 4 plastic black cleats and using the cut in half bungee cords, I knotted them and hook them in the cleats!


Continued....

 

[InMotion]

Last but not least, I used two pieces of carefully chosen Maple to tighten the cover by placing them in the splashwell and wedging them under the steering to let the water drain into the splashwell out of the cover... ya... I know it's a pretty bottem feeder solution but I spent over an hour trying to get it to work with bungees etc. This works great!




Here are some shots of the newer motor!



The Captain..



Awesome brand spanking new BRP controls!



After driving it for the last 3 weeks here are my conclusions!

1. It is slower ---- no doubt it would be.... it accelerates like a 4 stroke --- linearly.
2. Top spead is 28 mph with 2 adults and 2 kids --- one decent size now!
3. It's dead quite at idle and going slowly.
4. It uses roughly 3 times LESS fuel than the 90! So far I have used only 3 gallons this summer which is great!
5. I was able with ease to be able to tow and launch the boat with all of the weight shedding.... great thing now!
6. Curious thing is that the boat is a little more tippy... I think it is because with the 90's lower unit being so heavy it was like a sail boats heavy keel and kept the boat very steady. Funny thing....

Overall, very happy overall. It is slower for sure to accelerate ---- especially when loaded with 3 adults, 2 kids and 4 dogs! But it runs about 24/25 loaded up --- just takes quite a bit longer to get there!

Anyway, a bit of an update but hope everyone is having a great summer!!!

Take care,

Jim

 

[Tnstratofam]

Jim I just wanted to say the interior of your boat is stunning. I love the wood accents, and it really compliments the paint well. Sounds like you all are having a good time on the water. Nice solution for the cover as well. Hope you all have a great rest of the summer.

Dave.