Starcraft Holiday senior project: Convert to twin Jetski drives

[dozerII]

Any new progress on this great project??

 

[Bondo]

Ayuh,.... A couple issues I see with the motor mounts, the 1st set were made to too big a metal,....

Donno if yer 'puter program takes into effect the .063" ribs they mount on,.....

I built motor mounts in my Islander for the 4.3l outa .090 aluminum sheet, pop-riveted to the tops of several ribs,....

The 1/4" attached to the .063" is a hard spot, 'n will tear up the lighter metal,.....
Thinner metal is Very strong, when bent into usable shapes,... structure is strength,...
Possibly won't need any wood,...

I think I'd bend up some aluminum channels, a few inches wide, 'n tall, than as Long as possible to pick up as many ribs as possible,...
Riveted to the ribs will work,....
Rivetin' to the hull will dirty the water leadin' into the pumps,....

The angles of the motor's part of the motor mount, is gonna complicate alignin' the motors, no matter how ya get there,....

 

[drev500]

Hey everyone!

It has been a long, very long time since an update has been made and one that I am very sorry for. Not to stray too far from the topic but I loss my brother back in February which had a major impact on my work and update. It took a little bit of time for me to get back on track but luckily I had the other members to help cover my work while I was with my family.

Well back on the subject, we were able to make some major head way. For the last few weeks we were chasing a cavitation issue that kept up from getting on plane and only allowed the boat to achieve a max speed of 9mph. It took us some diagnosing but we finally solved the issue which was a combination of overlooking the water flow into the intakes (intake grates were not sealed and lack of cavitation plate). Also there was the boats center strake on the keel that cause flow disturbances which we removed roughly 3/4's of.

We had our tech expo a week ago which we debuted the boat to the class. It was hit! Lots of positive feedback. I had a buddy make a video for us who has a drone, check it out: https://www.youtube.com/watch?v=uB9Z1WoRngw&feature=youtu.be

We launched the boat again this week after making the tweeks and came across a new problem with fueling (I believe). We used the one 3/8" fuel line and tee'd it to two 1/4" fuel lines which I believe is our issue along with some carb tuning which I never did when I rebuilt the carbs. Well even though being able to use one engine, we were able to get on plane. Not only did we get on plane with one engine but we were able to hit 33mph! Huge increase. I will update with photos soon and some more videos when we get back out on the water.

Thanks!

 

[Tnstratofam]

Sorry to hear about the loss of your brother.

Thanks for the update. I checked out the video and can't wait to see her finished.

When you had her at plane and at 33mph how did she handle?

Also are you going to reinstall a splashwell in the final design? There looked to be some spray from the jets coming in over the transom. A splashwell would eliminate most of the spray coming in there.

Keep us posted on progress.

 

[drev500]

Fuel Cell Mount


Exhaust Exit Port Side



Swim Platform. Once swim platform is covered with decking this will cut down on spray drastically.



Overall Engine bay... Will be cleaned up and have dog house made for it. Also, aft of the cross member will have sunpad added. That will be added in the coming weeks.



First Splash! Also, we had the boat painted


Electrical Distribution box behind helm with steering assembly visible.



Switches, fuel gauge, horn button and bilge switch

 

[drev500]

Sorry to hear about the loss of your brother.

Thanks for the update. I checked out the video and can't wait to see her finished.

When you had her at plane and at 33mph how did she handle?

Also are you going to reinstall a splashwell in the final design? There looked to be some spray from the jets coming in over the transom. A splashwell would eliminate most of the spray coming in there.

Keep us posted on progress.

TN, we will add a sunpad/ dog house to cover the engines. Also, there is no decking on the swim platform that covers the pumps. When the decking installed, I expect a major reduction in splashing. The transom board is marine grade that is also sealed in epoxy. The splash was not a huge concern for testing but will be addressed soon.

She handled very well at 33mph. Although running on one motor there was some significant correction given to the wheel to keep her running straight. When we first took off both motors were going and it tracked straight as far as I could tell. Tough to call since it was only for a few short moments before the engines started bogging soon after plane. The pure excitement kept me from paying attention.

 

[drev500]

Here is a short clip from today. Sorry for the horrible quality. This video shows the bogging issue with one motor upon take off. Once the revs build it does take off. I have few ideas but still not 100% sure until I dig into it. I am open to ideas. The carbs were never tuned when I rebuilt them so I am sure that has to do with it. Never tuned carbs before so that will be fun...

This is with one motor. Hopefully you can tell how excited we are.

https://www.youtube.com/watch?v=fZOaq43-kPk

 

[Tnstratofam]

:encouragement: Outstanding. I wondered how she would track with the jet drives. The outboard on our SS has me keeping a slight pull to port on the wheel as she always wants to turn starboard at speed. On our Stratos with the sterndrive she tracks much straighter at speed although both our boats tend to wonder a bit when we are off plane.

Do you feel the exhausts both exiting on the port side causes any extra pull one way or the other?

 

[Tnstratofam]

Just watched the second video. Very impressive. I couldn't help but smile when you all got up to speed. :rockon:

 

[Willyclay]

Please wear PFD's while checking out the boat, especially with no seating. Lost a brother also and know how hard it is on a family. Be safe!

 

[TruckDrivingFool]

Sorry to hear about your brother. :blue:

As much as we like pics around here video is better. Thanks for posting it for us is great to see the excitement when things start working.

The boat is looking great and you guys are making excellent progress.

 

[sprintst]

Your brother would be proud man. That is some cool stuff you guys came up with and executed.