new build

[PSG-1]

its definitely in the works, although I been laid up in the house for 4 days with the flu and havent touched it. I think this engine will push this sea ark very good. Im just waiting for a little extra funds to buy my jet pump and engine rebuild kit. Other than that the engine is pulled out and everything is setting in the shop floor ready to be installed, but nothin will get put in until the jet pump is installed.
The pump will determine where everything will go. Im gonna try to keep from trimming the driveshaft down, but if i have to in order to get my rear deck the length i want...then i will

Well, it appears that you already understand a concept that I failed to understand on my first build....that the pump is the first thing to install, as it determines where everything else goes. 8)

That's why the shaft on my pump has been chopped so short. On the next build, I will know better. When I did mine, not many people were doing this, and there weren't many (if any at all) internet forums with knowledgeable people willing to help. So, I was on my own with that project, doing everything by guess-timation, and trial and error.

 

[Imgoodatwhatido]

well it came in today, its time to start chopping and fittin it together. Christmas put a damper on my wallet so I havent got much done as of lately.

 

[Imgoodatwhatido]

As far as that half inch. I plan on shortening the shaft tube, and the shaft as well. This should shorten the pump by at least 6 inches. That will allow me to machine the front of the pump to match the rear.

 

[scubapro820]

I want to see more pics on this thing I'm excited to see your design

 

[PSG-1]

well it came in today, its time to start chopping and fittin it together.

All right! =D>

That's a pump from a GP1200. I can tell, because the threaded dogs are on the sides of the exit nozzle, instead of on the top and bottom, like the XL1200. That's because the GP1200 uses a trim ring between the thrust nozzle and the steering nozzle, where the XL uses a reverse bucket that's mounted to the steering nozzle.

Trim is great for fine tuning the boat's attitude for varying loads. However, because the GP has a trim system, it does NOT have a reverse like the XL1200. So, if you want a reverse system, you will have to buy a reverse gate for something like a Yamaha VX110, and make a set of mount brackets that attach to your transom. Then mount the reverse gate to that, and use a push-pull cable to operate the reverse system, along with another push-pull cable for your trim system. Trust me, reverse is a nice thing to have for smoothly docking and trailering your boat.

When you get ready to mount the pump, find the centerline of your boat, then carefully measure your cut-out, keeping it squared and centered with your reference line. After mounting the pump, put the engine in position, and then determine how to build your mount system that will bring the engine coupler into alignment with the pump coupler. Ranchero and me built rail-type mounts, although, Ranchero's design is a little better than mine, because it allows for some adjustment.

If you are using a spartan jaw coupler, when you are aligning the engine, use a straight edge, laid across the 2 halves of the coupler, then use a feeler guage to check for mis-alignment. The maximum allowable mis-alignment is about .020", any more than this can cause premature bearing failure of the pump. This is the most critical operation of the entire build, so, take your time, and be as precise as you can. I got mine within about .010", which is pretty precise, all things considered.

 

[PSG-1]

As far as that half inch. I plan on shortening the shaft tube, and the shaft as well. This should shorten the pump by at least 6 inches. That will allow me to machine the front of the pump to match the rear.

You can cut the tube all the way back to the fat section just behind that first tube support strut. The bearings and seals are farther back than this, pretty much at the very back end of the tube.

One thing you can do to beef it up a little bit, is to get a set of self-lubricating bronze sleeve bearings. Get an inner, and an outer bearing. For the inner, you want to bore it where it's about .001-.002" larger than the driveshaft for its ID, then, turn the OD to a size that will match the ID of the outer bearing (you'll have to machine that ID as well) Best to machine this where it's a press fit, or even an interference fit, where one part is heated and the other part is chilled, then put together.

Finally, machine the OD of the outer bearing sleeve where it's the same as the ID of the shaft tube. To secure this bearing into the tube, you can drill and tap the tube and bearing sleeve, then install a zerk fitting. This will act as a retainer, as well as giving you the ability to lubricate the forward end of the shaft with a few pumps of grease about every 10 hours. The bronze sleeve bearing helps absorb vibration and deflection, and cuts down on excessive wear to the rear bearing and seals. It's like a carrier bearing.

 

[Imgoodatwhatido]

Remember that I still have all the parts from the 2004 ski. So I have all the trim and the reverse bucket at my disposal. I should be able to remove this cone and put the cone from my xlt pump on it. Then everything should bolt right up. I'll look into the pump mod and see what I can come up with. Its hard for me to visualize what your talking about without it setting in front of me. This pump I just bought has what looks to be a nearly new impeller in it. Either that or its in really good condition. Not a nick on it. The wear ring is really tight as well. I know of a company called Timken. They make extremely high quality bearings for most any application. We use to use them a lot on a gigantic stretch film press I use to run. They make ceramic sealed bearings that last an extremely long time. Those machines ran several thousand RPMS nonstop 24 hours a day, 7 days a week, and those bearings were changed once a year whether they needed it or not. I may go with something like that. Once I get the pump milled to where i want it Im going to weld it to a boot to get the desired fit I want. When its all said and done when I bolt the pump in I will be bolting 2 pieces of 3/8" aluminum together. I still need a center jug for the engine and a rebuild kit. Its gettin deep $$$$$$$$$$$$ lol

 

[PSG-1]

Remember that I still have all the parts from the 2004 ski. So I have all the trim and the reverse bucket at my disposal. I should be able to remove this cone and put the cone from my xlt pump on it. Then everything should bolt right up

An XLT thrust nozzle should bolt up to the GP stator assembly, the bolt pattern is the same, they are both 155mm pumps.

. I'll look into the pump mod and see what I can come up with. Its hard for me to visualize what your talking about without it setting in front of me.

Well, if you run into any issues or have any questions, let me know, I'll be glad to help out with some advice based on my own experience with a similar pump.





See, the 2 pumps are virtually identical. You can see how I cut down the shaft housing on mine.

This pump I just bought has what looks to be a nearly new impeller in it. Either that or its in really good condition. Not a nick on it. The wear ring is really tight as well.

Max allowable clearance from impeller to wear ring is about .025" Any more than that, means the prop, or the wear ring are worn and need to be replaced for maximum pump efficiency. I think minimum clearance is about .005" Props can be rebuilt by a company called "Impros" They can also re-pitch any prop to your specs.

I know of a company called Timken. They make extremely high quality bearings for most any application. We use to use them a lot on a gigantic stretch film press I use to run. They make ceramic sealed bearings that last an extremely long time. Those machines ran several thousand RPMS nonstop 24 hours a day, 7 days a week, and those bearings were changed once a year whether they needed it or not. I may go with something like that.

I've heard of Timken bearings. But here's the issue....getting bearings that have an ID the EXACT size for the OD of the shaft, AND having the OD being the exact size of the ID of the pump shaft housing. This is why I say go with the oil-impregnated, self-lubricating bronze sleeve bearings, you can machine them to whatever size you want. And they work.

In fact, take a look at an online parts diagram of your pump. You will see that in addition to the 2 seals and the bearing, there is a forward bearing that has a splined rubber outer housing. The forward bearing itself is nothing more than a bronze sleeve bearing.

Once I get the pump milled to where i want it Im going to weld it to a boot to get the desired fit I want. When its all said and done when I bolt the pump in I will be bolting 2 pieces of 3/8" aluminum together.

I'm not following you on this. :?: When you say 'boot' do you mean coupler? If so, what you want to use is a spartan jaw coupler, it's two inter-meshing disks with cogs, cast from aluminum, and there is a rubber 'spider' that goes between them, to eliminate the metal-to-metal wear, and some deflection and mis-alignment.

Note that I said "some" mis-alignment. You'll still have to be within .020" with your alignment, regardless of which type of connection you use. Any more than this will cause premature wear of the pump bearings.

Or when you say "boot" are you referring to making a wedge-shaped piece to deal with the angle of the pump where it goes into the boat? That was a real PITA when I did my build, I cut tapered strips of aluminum, and made a tapered 'shelf' for the pump to fit tightly against.

I still need a center jug for the engine and a rebuild kit. Its gettin deep $$$$$$$$$$$$ lol

If you haven't done so already, check SBT, they rebuild jet ski engines, and they sell all types of parts and rebuild kits.

 

[Imgoodatwhatido]

im gonna remove the 1/2 inch of lip on the bottom of the intake housing. Once removed im gonna weld some 3/8 plate aluminum to make a surface to bolt to. Im more or less gonna redesign the intake housing.

 

[PSG-1]

OK, I got ya now. You're basically making a mounting flange for the duct.

The only issue is that if you ever have to replace the duct, you're going to have to go through the entire process of modifying it all over again. I would imagine it would take almost as much time to modify the duct, as it would to configure the boat so the factory duct will bolt right up.

For example, on the first version of my jetboat, I had a lot of customized and modified parts. When I did the second configuration, I tried to move away from having to modify factory parts when possible, I re-configured things so the factory parts would work without modification, instead of modifying parts to fit the existing configuration.



It's something to consider.

 

[Imgoodatwhatido]

****, that makes sense. Advice appreciated

 

[PSG-1]

Here ya go:


This one shows the hull, and the inner floor plate made from 1/4" aluminum. The engine mounts are welded to this plate.





OK, in this one, you can see the "wedge" I'm talking about. That was a major PITA. This operation is best done with the boat upside down....trust me on this! I did it the hard way, with ME being upside down. Won't do it that way again, I can guaran-****-tee you that.





This one shows the box form that gets welded into the transom. It's also made from 1/4" plate





You'll also need to form a sealing ring by rolling a strip of aluminum, and welding it, like this:






From the rear, you can see the radius of the box, where the pump will fit







And this one shows the pump, bolted up:

 

[Imgoodatwhatido]

once the pump was installed, how did you get the sealing ring to seal against the pump?
It looks like some type of silicone maybe?

 

[PSG-1]

once the pump was installed, how did you get the sealing ring to seal against the pump?
It looks like some type of silicone maybe?

Actually, it was 5200, which became a lesson well learned....to NOT ever use 5200 for anything removable!! Turns out I had a mis-alignment which damaged the bearings, when I had to pull the pump, I found out that 5200 doesn't come loose :shock: That pump had to come out in tiny little pieces, after busting it apart with a BFH. Which, in this case, was OK, because the shaft housing was also damaged when the bearings failed (again, alignment is a very important factor)

So, lesson learned, don't use 5200, use RTV 'Ultra Black' silicone.

The way you want to do it is to put a bead of sealant on all mating surfaces, then, bolt the pump into the boat, as you tighten the bolts, the silicone will mash out of the gaps, indicating a proper seal.

It's definitely a 2-man operation, you'll need an assistant to help hold the pump tunnel, while you install the two bolts on the forward end.

Also, you want to have the wear ring, stator, and thrust nozzle in place on the pump when you do this (use the 4 long bolts that hold the pump assembly together) This way, you can go ahead and tighten the 2 bolts that hold the wear ring, and the 2 bolts that hold the thrust nozzle, as this will support the rear end of the pump.

You can tighten the two bolts on the forward lip, and you can also go ahead and thoroughly tighten the 2 bolts that holt the wear ring in place. But, do not overtighten the thrust nozzle bolts, you only want to tighten them enough that they don't rattle. Excessive tightening of these 2 bolts will put the pump in a bind.

Once you have the pump bolted in, allow the RTV silicone to cure, then, tilt the boat up, put the plug in, and fill the stern with water, and look for any leaks. If there are no leaks, then proceed to install the driveshaft and impeller assembly.