shimming superjet pump

[SharkB8]

I replaced my wear ring, pump bearings and impeller and the pump went back together just fine.

But when I go to bolt the pump back on, the shaft is at the very bottom of the hole in the hull (see pic1), even though the rear end of the pump is waaaay down, like 1/4 inch (see pic2).

To get the shaft in the middle of the hole, the rear end of the pump has to be push down even further. I don't mind shimming it that far down if that's what it takes, but damn.... its a lot more than 1/4 inch. That seems excessive.

Now I did have my 1990 sn's cheap plastic reduction nozzle replaced with an aluminum one so it could be bored out (pic3). But it was in perfect condition and should fit... ? ?

 

[H2O FIEND]

You definitly want to shim it up to center, no matter how many shims it takes. Totally balanced drive and properly shimmed motor results in less wear on bearings and seals on motor,midshaft and pump and smoother running ski.

 

[SharkB8]

I ended up shimming the nozzle down a little more than 1/4 inch.

With trim like this, I'm sure I will never do a flatwater backflip.

 

[oxnard111]

i had massive trouble shimming my square. i think the pump mounting area just warps over the years.

yours looks to be a little off to one side also, which was my problem, but mine was WAY off to one side.

engine compartment looks good. what did you paint it with?

 

[tightithrash]

mine took alot aswell

 

[SharkB8]

My spline was off side-to-side just because the ski was laying on its side when the picture was taken. When sitting upright, it wasn't quite so bad.

I took jfw432's advice and painted the hull with appliance epoxy from Wally World. I am very pleased with it. Potent stuff though - my lungs hurt for a few days because I didn't take #.0's advice and wear a mask.

 

[oxnard111]

My spline was off side-to-side just because the ski was laying on its side when the picture was taken. When sitting upright, it wasn't quite so bad.

I took jfw432's advice and painted the hull with appliance epoxy from Wally World. I am very pleased with it. Potent stuff though - my lungs hurt for a few days because I didn't take #.0's advice and wear a mask.

in order to get a true reading on the center of the shaft in the circle all the pump bolts need to snug. if any are loose your really not giving yourself accurate information.

 

[H2O FIEND]

in order to get a true reading on the center of the shaft in the circle all the pump bolts need to snug. if any are loose your really not giving yourself accurate information.

TRUE...TRUE BRO, Everything has to be snugged up tight on th pump as if your going to bolt the rideplate back on and ride or you'll be off. And if your off to the side or too far up or down after snugging everthing up you just play with shims on the four pump mounting legs until its centered up. Basically shaft has to be as close to ceter as possible.

 

[SharkB8]

Yeah, it changed a little after everything was tightened up, and I only have about 1/4 inch of shims now rather than a lot more than 1/4 inch like I expected.

I didn't shim the front at all. I didn't think they were supposed to be shimmed. I probably should have tried it, given the extreme shimmage happening at the rear.

Oh well I"m gonna run 'er like this and see what happens.

 

[Polish jet pilot]

I had/ have simialr problem on my RN. It is a pain in the butt - kawasaki did it much better IMO.

Shimming the pump: only the rear bolts accrodingly to Yamaha manual.

Andrew

 

[H2O FIEND]

I've got the genuine yamaha repair manual from yamaha corp. and the clymer yamaha manual and neither one states not to shim the front of the pump. They usually are'nt shimmed in the front but sometimes when changing out to a afetrmarket nozzle,such as Pro-Tec you need to add extra shims. That would be like saying you cant install motor mount shims to the front motor mounts because they were'nt already there. The bottom line is the drive shaft should be centered in the hole behind the mid-shaft to give you a balanced drive and not be putting added pressure and stress on pump and motor bearings. Just like making sure your drive shaft on your vehichle is balanced.

 

[oxnard111]

you can't really add shims to the front even if you wanted to, b/c there are dowel pins in the on the front pump mounting legs that stick up into the ski that inhibit side to side adjustment. the shims would interfere with these dowel pins.

 

[H2O FIEND]

Not seeing locating pins,and even if there were,which on the FX1 there might be, If you cant get a slotted shim under that leg even if there is a small locating pin maybe you should'lt have a wrench in your hand. Rarely is there more than a couple of shims in the rear if any at all but in certain situations especially when using aftermarket nozzles or pumps you may have to use one or two thin shims in front. Once again you do whatever it takes to center the shaft in the hole.

 

[oxnard111]

Not seeing locating pins,and even if there were,which on the FX1 there might be, If you cant get a slotted shim under that leg even if there is a small locating pin maybe you should'lt have a wrench in your hand. Rarely is there more than a couple of shims in the rear if any at all but in certain situations especially when using aftermarket nozzles or pumps you may have to use one or two thin shims in front. Once again you do whatever it takes to center the shaft in the hole.

I didn't mean to say that is is not possible to add a shim if you really want to, but it was just not intended by yamaha to do so. there are pins on superjet wear rings (atleast 95% of the ones I have touched)... best pic i could find, but the right mounting leg should also have a pin, but was missing off this particular unit.

 

[H2O FIEND]

I didn't mean to say that is is not possible to add a shim if you really want to, but it was just not intended by yamaha to do so. there are pins on superjet wear rings (atleast 95% of the ones I have touched)... best pic i could find, but the right mounting leg should also have a pin, but was missing off this particular unit.

Your absolutly right in that it was not intended by yamaha having shims on the front and sometimes there are none in the rear. But sometimes when your modifing a ski with aftermarket parts that dont fit like stock parts you make other adjustments. I have even pulled midshafts out for a rebuild and seen that yamaha had not done a good job at shimming the pump and had to add or remove shims just to center up the shaft. Sometimes you just figure it must have been a friday afternoon at the factory and someone had happy hour with saki and sushi on the brain.

 

[Polish jet pilot]

Would a washer work as well as a oem shim? I know I need to adjust the drive shaft but have no "yami" shims...

 

[H2O FIEND]

If you dont have a metal shim you can take differant thickneses of sections of sheet metal or tin and cut to fit or if all you have are washers you can use one. Make sure whatever you are using is wide enough to cover most of the flat surface on the mounting leg around the bolt.

 

[SharkB8]

I bought a complete set from Tom 21 for 50 bucks.

They are engine shims so they are a little bigger, but they worked fine.

 

[Polish jet pilot]

sheet of metal sounds more economical
Question: what is more important :

well shimmed pump, or well shimmed motor to intermediate shaft??

Obviusly both are really important, but still...??

 

[H2O FIEND]

But still what? They are all just as important and point A to point B and then C means just that, three points of support, and anyything in the middle is still a supporting mechanism. You could disconnect your shocks from your truck and still drive it but what dammage would that do to other components. From the nose of your crankshaft to the tail of your pump shaft, all adjusting and leveling points are equally important.