a new jet ski jet boat project

[PSG-1]

LOL, I knew what you meant. :mrgreen:

.91 mm would be like a beer can.

 

[Ranchero50]

Thi mod it to fit my hull is much thicker than the alumacraft .040 ere are 3 longitudinal stringers and 2 horizontal stringers 1 I am going to re install after I mod it my hull is much thicker than .040 its..091 or .080 the rear mount plate is 1/8 " and the most rigid part of the boat thanks for the concern guys but I also have put thought into its rigidity I do have more to be added to the hull later also. In Minnesota we have very smooth flat waters

Sorry if my post sounded too negative. I would beef up those little ribs in your hull with maybe some 1"x3"x.125" angle stood upright, trimmed to fit the contour and then welded to the existing ribs. Then you can tie the whole hull structure together from the seat to the transom with some decent stringers. I think I used 2x2x3/16" angle for the stringers and had the motor cradle mount to that. You could use that as a floor base.

https://www.tinboats.net/forum/viewtopic.php?f=21&t=8385

For your cradle, you can drill out the top motor mount holes and insert a round rod spacer so the bolts won't collapse the channel over time. I was dissapointed at how poorly those rubber pucks dampen vibrations. I tapped my stringer for the bolt, then lock nutted it too and it hasn't come loose yet.

Jamie

 

[Ride_Klein]

Cool project.

I'll echo what the previous guys have said about stiffening the bottom around your inlet. My project has a couple stiffening ribs that run through the area of the inlet and I'm glad they are there. As a matter of fact, I wish I had a few more around the pump tunnel I mounted. The jet will make you want to run very shallow. Running very shallow is a lot of fun, but you will hit things. You can see how things could get messy in a hurry.

Keep up the great work. Read through my thread if you'd like. I'm happy to offer any advice, but PSG and Rancherro are the experts for sure.

https://www.tinboats.net/forum/viewtopic.php?f=21&t=22354

RK

 

[scubapro820]

Thanks for your support guys, Ive looked at all three projects. Actually all b4 I even got started on mine lol. I haven't replied much since sat just been busy with life and thinking of ways to engineer a support structure and incorporate it as part of a mount for my cdi/fuse box and rear deck that I plan on building eventually.

 

[PSG-1]

Here's an idea for the CDI mount:



This is how I mounted the CDI in my boat. Used a piece of aluminum angle, welded between some structural supports, and bolted the CDI to this piece of angle. Had to put it here, as there was no room to put it anywhere else.

 

[PSG-1]

For your cradle, you can drill out the top motor mount holes and insert a round rod spacer so the bolts won't collapse the channel over time. I was dissapointed at how poorly those rubber pucks dampen vibrations. I tapped my stringer for the bolt, then lock nutted it too and it hasn't come loose yet.

Jamie

Good idea for putting the spacer/sleeve in the tubing, to keep the engine weight from collapsing it. I would have suggested a strip of 1/4" X 3" aluminum plate on top of the tubing, but the spacers will also work. Even on flat water, without the factor of hull chop, engine vibration is a serious factor to contend with. When you've got that much weight vibrating around, it's gotta be secure, especially at lower RPM's, where vibration is really pronounced.

Certain types of motor mounts are better at isolating and dampening vibration than others. The Sea Doo 717 mounts do transfer a lot of vibration. I can remember my Sea Doo 14' Speedster with twin 717's, it had a lot of vibration, even in a fiberglass hull.

 

[scubapro820]

I was talking with my aunt for a bit about how I think my 2500$ boat will be faster than her 60,000$ boat @42mph I estimate 45-50mph for mine. Any way turns out she works for a company that makes custom isolation mounts for generators all the way to ships kinda neat so she can custom engineer a set if I need to !! any how i mounted my cdi box and intermediate shaft bearing/ dampener thing. I accidentally made it so I have to un screw the cdi box to grease it but oh well small overshigt. then I finished the rear pump housing adapter thing I built and also reattached the corner braces that support the transom somebody had previously used self tapping screws I used stainless steel 1/4 20 fasteners that will help stiffen the hull more too. I am also going to make a deck that stiffens the keel area of the hull too. I wont order my steering gear for a couple weeks but I think testing will start in april. Does anyone know about a good spray on sealant? kinda like a rubber urethane spray or bedliner like materiel to prevent water from coming in . otherwise I have to rtv 1000 rivets lol

 

[PSG-1]

Well, it looks like you're almost through the worst of it, getting the pump and engine installed.

Everything else should be fairly easy, the only quirk might be with the steering, depending on the setback of the steering arm from the hull, as I mentioned earlier.

Also, extending the throttle cable, if you have to, might be a little tricky. Some Tigersharks use a dual linkage, that controls the carb butterflies, as well as the oil injection pump. A single cable runs into this. You can open up this housing, and change out the cable, as well as the conduit that goes into it from the helm.

You can buy throttle cable conduit and fittings on the net, just check around. I would suggest not using the galvanized wire cable, though, get some 1/16" diameter SS cable, as the galvanized stuff will corrode, and will fail.

Let me know if you run into any trouble with the cables, etc....I can save you some aggravation and time.

 

[scubapro820]

I got side tracked last week and the week b4 that I got a dana 44 off an 84 jeep wagoneer, then I got an 83 k20 6.2 diesel truck for free! it had "major" electrical problems I went over jumped a couple wires drove it home and fixed the "problems" sunday. So I have 3 projects but this weekend Im going to install the helm and measure for steering cable length. Did I mention I made an engine compartment out of 1x1 and 1/8 plywood and stapled carpet to it, should be quiet. I also leak tested the hull, seems pretty water tight, about 1 gallon in 10min. So the rest is probably gonna be boring lots of wires hoses and such with few updates until I get to testing.

 

[PSG-1]

If you want to dampen the engine noise a little more, get some acoustical "egg crate" foam from McMaster-Carr and place it on the inside of the cowling. It will make a big difference. It's much better than Dyno-Mat, and it's also a LOT lighter in weight.

As far as leak testing, 1 gallon in 10 minutes may not seem like a major leak if you're on the water for a couple of hours, but if you plan on leaving it moored to the dock overnight, then ANY amount of leakage is unacceptable.

And while you may have a bilge pump and float switch, my experience with that setup is that more boats have sunk BECAUSE of an "automatic" bilge pump than have ever sunk without one at all. it gives you a false sense of security, and float switches are notorious about either not coming on, and the boat filling with water, or, if they do turn on, then they don't turn off, it kills the battery, then, any more water coming into the boat is no longer pumped out, and the boat sinks.

If it were me, I'd try to find the source of the leak, and either weld it up, or use some 5200, and try to get the boat water tight.

Keep us posted on the installation of the steering system, and remember my advice about the setback of the pump from the hull, you may not be able to just put the cable through the transom, you might have to inset it, or extend it out from the hull, depending on the distance from the transom to the ball joint of the steering arm of the nozzle.

 

[scubapro820]

I got my steering connected ready for cable measurement working on electrical /harnes-extension stuff ill try to get more pics im having issues making a guage bezel (the circle cutting part) but yeah I wanna be running next week Still have to make the mount for the back side of the pump and somesuch but it is moving along....

 

[PSG-1]

You can use a 2" hole saw (for small guages) or a 4" hole saw if you're trying to do the cut-outs for your gauges. it's much faster and much more precise than trying to cut with a saw or other methods.

 

[scubapro820]

Its been slow since last week, just dont have the free time just need a day to finish stuff up, basically I have to extend the exhaust measure and install the steering cable connect trim, run the oil hose and throttle, I think I am going to shoot for sea trials by may 1st got a ton done tho any reason i shouldnt install an inline primer bulb or primer pump to fill up the pulse pump ? I have 8 ft of fuel line also I mounted the tank from the ski in the bow of my boat

 

[PSG-1]

Its been slow since last week, just dont have the free time just need a day to finish stuff up, basically I have to extend the exhaust measure and install the steering cable connect trim, run the oil hose and throttle, I think I am going to shoot for sea trials by may 1st got a ton done tho any reason i shouldnt install an inline primer bulb or primer pump to fill up the pulse pump ? I have 8 ft of fuel line also I mounted the tank from the ski in the bow of my boat

I wouldn't recommend installing a primer bulb. Jet skis don't use them, and for good reason, because the carbs and fuel system of a jet ski are a little different than those of an outboard. First off, the vent line on a jet ski has a check valve that only allows air in, but nothing to flow out. This allows pressure to build up, which is what helps to feed the system. Outboard portable fuel tanks have free-flow vents. Most permanently mounted tanks for outboard also have free flowing vent lines, no check valves.

A primer bulb forces fuel through the line. You don't want to be trying to force fuel through the system like that, it could damage a diaphragm in one of the carbs. Once you have fuel in the tank, and all the lines are hooked up, when you start cranking it, the fuel pump will start to pull a vacuum. It might take a few tries, but it will catch prime and pull fuel to the carbs. Once it's primed, it will stay primed. Make sure to install an anti-siphon check valve on the feed hose going to the carbs.

Now, depending on how hard it is to cold-start, you might want to think about installing a primer KIT. Basically, it's a small nozzle for each carb (you have to drill and install the fittings), each nozzle has a barb fitting, and some 1/8" ID hose that hooks to each fitting, then to a primer knob mechanism. This mechanism is hooked to a T fitting on your reserve fuel line. So, when you push and pull the knob a few times, it gives a quick shot of fuel to the carbs, making a choke unnecessary. Saves on battery life, too.

I had one on the TS1000 engine in my jetboat, worked really good, even on mornings when there was ice in the marsh. But now with the 4 stroke, it's no longer necessary, as this engine uses an electrical fuel pump that pushes fuel at about 45 PSI. Turn the key, it fires up, no question, every time.

 

[scubapro820]

excellent observation on the diaphram issue, i did make sure to use the check valves (in correct orientation) I measured for steering cable length and today I will order a 13 ft cable thats about a foot longer than the 12ft 3 inches but i want to be on the safe side, ive been known to order the wrong part before! and my wife is usually very unhappy with that lol. As far as battery is concerned should I stick with the Agm battery the tigershark used or is it ok to use my marine starting battery? There are no extra loads on the original (lengthened) tigershark harness. I dont want to be short starting power or burn up my stator.

 

[PSG-1]

excellent observation on the diaphram issue, i did make sure to use the check valves (in correct orientation) I measured for steering cable length and today I will order a 13 ft cable thats about a foot longer than the 12ft 3 inches but i want to be on the safe side, ive been known to order the wrong part before! and my wife is usually very unhappy with that lol. As far as battery is concerned should I stick with the Agm battery the tigershark used or is it ok to use my marine starting battery? There are no extra loads on the original (lengthened) tigershark harness. I dont want to be short starting power or burn up my stator.

Always better to order a cable a foot or so longer than you measure for. You can always tuck the slack away someplace if it's a little long, but if it's too short, you can't stretch the dang thing!

As for your battery, if the only thing you are running is the engine, no lights, radio, etc, an AGM battery might be OK. But, if you're running anything else, you should use a regular marine battery. If it were me, I'd go ahead with the full size battery, that way you know you have the cranking amps.

 

[scubapro820]

That ok for a stator to charge ?

 

[PSG-1]

That ok for a stator to charge ?

I'm not sure what the amp output is on the stator of the TS engine. The manual may specify it.

I know that my Yamaha MR-1 High Output engine puts out about 14 amps at 6K RPM, but then, this engine came out of a boat, not a jet ski.

That said, if your stator has a low amp output, it will just take longer to fully charge the battery. I ran a marine battery on my TS1000 engine...actually 2 marine batteries, hooked together. Never had any problems with the stator on my engine.

 

[scubapro820]

I'll take ur experience as a yes it'll be fine ill be sure to let u know when I get more done

 

[PSG-1]

When I had the TS engine in my boat, I had a lot of other stuff hooked up, like nav lights, illuminated gauges, radio, depthfinder, blower, bilge pump, etc. So, the following info is for if you decide to install anything, particularly nav lights.... how to cut the voltage consumption.


I noticed that the voltage on my depthfinder would drop when I'd cut on the nav lights. Nothing that the engine couldn't keep up with, but it would drop to around 11 volts.

I switched to LED's for the nav lights and instrument panel, and that reduced the voltage consumption significantly.

Later on when I put the 4 stroke in my boat, I installed a set of prow lights that had 55 watt halogens. Whenever I'd cut these on, the volt meter would drop big time, even with a stator output of 14 amps. So, I switched to MR-16 LED's, and that solved that issue.