Thread: GPRXP Engine installation.
11-02-2007, 10:22 PM #1
GPRXP Engine installation.
- This assumes you are using the same mid-shaft design as in the Vigilante designed and sold by Ted Thompson. You can find this info in another thread. If you have gone a different route, then this won't help you fully.
- Before you install the engine, you will need to "relieve" the hull, in two locations to fit the engine low enough to naturally line up with the driveline. There are pictures around showing different cutouts.
- Engine mounts can be fabricated to utilize the stock mounts.
- Remove intake manifold. Install exhaust manifold.
- Install your rubber mounts on the engine, snugly, but dont tighten down. If you have trouble with your engine hoist not allowing you to move your engine around, due to interference with the stand, you might have to put the mounts on after it is in the hull.
- Lower down using a cherry picker. This engine weighs over 220lbs, so I wouldn't suggest doing it by hand.
- Line up to the centerline of the crank and driveshaft and start all 6 rubber mount bolts, (or drop over the adapter studs, depending on which adaptors you have.)
- Install mid-shaft assembly (including bracketry) into the engine, and wiggle down into place on top of the grate bolt holes. The bracket and bearing assembly should be loose the first time you align everything.
- Install driveshaft, into mid-shaft. It should go into place without a struggle. If there is interferrence, then you might have to re-adjust your engine before continuing.
- Tighten the pump housing into place, as long as there is NO BINDING. YOU MUST HAVE ALL THE DOWEL PINS INSTALLED.
- Using mirrors and bright lights, look at the driveshaft where it comes through the hull. It should be centered. If not, move the engine left/right or up/down, until centered.
- Look at front of mid-shaft bearing assembly. It shouldn't look tweaked or bent to one side.
- Once you have the engine centered (don't forget your front/back centerline on you engine too) then tighten down all the engine mounts.
- At this point your mid-shaft support bracket, which should be loose and not securely attached to the bearing, can be snugged down to the intake gullet, and intake grate.
- THEN tighten down your bracket to the bearing assembly.
- At this point, everything should be aligned, and you should be able to remove and install the mid-shaft, or pump at will. You don't need to pull out the mid-shaft unless you are pulling the engine.
- Dont forget to seal underneath this bracket on your final installation, or you will have a "mystery water leak" in the hull. I suggest to install a thin rubber gasket before your final fitment.
- If you havent done so yet, tighten down your intake bolts
- Before you are done, you must install the rubber hose, behind the bracket to the hull feedthrough. This is a real PITA on this design. Sorry.
- Cut the hose long enough to reach both ends with clamps, but not so long that you can't feed the hose on/off.
- Feed your worm-gear clamps over the hose, after installing the hose. It's easier. I take them off the same way.
Some instructions for when the engine is already in the ski.
- Loosen the four rear plate bolts in each side, so that the butt of the engine slides back and forth.
- Loosen the single front mount top bolt so that the nose of the engine will pivot.
- Remove the two hose clamps, and loosen the small rubber hose from the coupler and hull.
- If you can not see the spot to measure, due to the rubber hose, then remove the pump, remove the hose, and completely remove the hose and reassemble the pump. THE PUMP DOWEL PINS MUST BE IN PLACE.
- Under the ski, remove the two intake bolts from the metal plate inside the ski.
- On the feedthru coupler, loosen the 3 bolts, so that the coupler, rubber red gasket and L-bracket seperate, and are not one unit anymore (almost flopping around.) Remove the bolts if you wish.
- The feedthru should be pretty much not firmly attached to anything at this point just rotating on the mid-shaft.
- Move the engine back and forth....gently. The measurements on the tunnel hole will follow the engine.
- The measurements should be "eyeballed" with a small ruler. The closer you get it the better. Just BUMPING the engine with your hands will make a difference.
- Once you reach nirvana, or are tired of looking at that small damn ruler, tighten down all of the engine bolts with a little locktite FIRST. ALIGNMENT DONE AT THIS STEP.
- Crawl underneath and install the 2 intake bolts but DO NOT TIGHTEN YET.
- Snug the 3 bracket/coupler bolts WHILE PUSHING DOWNWARD on the bracket. Your goal here is to get the bracket to sit downward, in the assembled posiition.
- Give the 2 bolts underneath a little more "english" and repeat on the three up top. Tighten all of them down, finally.
- Re-install the rubber hose and clamps.
Once you figure it out, you'll see it's an amazingly simple arrangement, and is very, very similar to the seadoo engine alignment. The engine is aligned to the pump, and the coupler is the last thing to get aligned to the other two.
Last edited by Hydrotoys; 12-29-2007 at 12:19 AM.
11-14-2008, 11:30 AM #2
Two questions on alignment...
Should the measurement to the driveshaft @ 12:00 be the same as 3:00 and 6:00 ?
How do I check for level from the front mount to the back ?
I cant figure out how to get under the driveshaft to check for the up and down measurement..
11-14-2008, 12:10 PM #3
can't help you with alignment, your mid wall bracket turned out nice
11-14-2008, 12:20 PM #4
11-14-2008, 01:16 PM #5
11-14-2008, 01:17 PM #6
...and spin the driveshaft to makesure it isn't wobbling on you...
I sure hope you have dowel pins in everything at this point.
If your nice midwall bracket screws up your alignment, expect to eat splines. That bracket needs to be very moveable.
11-14-2008, 06:52 PM #7
Some conversion expert in AZ made the motor mount brackets . As it turns out I am completely shimless except one underneath my mid shaft support and one on the front motor mount (just because). Needless to say it was making me crazy. I am able to move the pump in and out without any binding whatsoever. From the looks of it I do not have a wobble when I turn it over by hand. Obviously the true test will be once I fire it up in the next few days.
One interesting note is my pump is no where near center to the opening. Once I got that out of the way everything literally seemed to fall into place. I was shimming to get it centered which I did not need to do.
11-14-2008, 06:59 PM #8
Like I said, take the measurements without the midshaft, then WITH the midshaft installed. They should be very close....and take the damn shim out of the front!
11-14-2008, 07:04 PM #9
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