96/97 Challenger 787 110 Jet Pump Service

[lilngineer]

I am planning on going through the pump of my boat over the weekend. Of those that have experience with it, what are the recommended items to replace and service while in there to seal pump and reduce cavitation?

Obviously these:

-Impeller
-Wear ring
-Oil
-Pump to hull seal


Any others?

What are the best sealing compounds to use?

 

[seadoosnipe]

Pump maintenance?....

When you say "resealing"....what exactly are you talking about? From what your describing in your list of parts, it seems your talking about the seals to your pump.

I assume you do not have a manual or you'd know that you don't "reseal" it. You do an air test to see if the seals are leaking, if so, you replace them.

In your pump maintenance, what you'll want to do is, drop open the weedless grate assembly and crawl under the boat. Take a set of feeler gages with you and measure the impeller to wearing ring clearance. Stick the feeler gage in between the middle part of the blades edge and the wearing ring. Anything greater than .40" is bad. The wearing ring has to be replaced.

Yearly, you should inspect and replace the oil in your pump with a 75 weight, synthetic, polyolester oil. If you do not take the pump off, you need to drop the reverser bucket and nozzle. Once this is done, you'll see the cone to the pumps shaft and bearing. Have a glass cup if possible and take the three screws out from that cone, gently tap it off and catch the oil. The reason you catch the oil is for inspecting it for water aeration, which it will be slightly yellow in color. Also, lookin to see that there IS oil in it. If the seals are shot, you'll only get water from it. Now, lift the tongue of the boat as high as possible to drain out as much oil as you can.

With the cone off, you can grab the impeller shaft and try to move it from side to side and front to back. If there is any slop at all, the bearings should be replaced. Which means pump removal. If the impeller is beat up pretty bad, this will cause aeration, you need to get another one (you can get a remanufactured one for about $30 bucks).

If you suspect your carbon ring and carrier seal are bad, you'll need to pull the shaft to get them off for replacement.

The work your lookin to do yourself is do-able if you have any mechanical skills. But you'll really be lost without a manual to follow. You can pay up a month for use of our library and get all the info you need to do the job.:cheers:

 

[lilngineer]

Seadoosnipe,

I think I may have worded my post a bit funny. I do have a service manual and realize the pump is not "sealed" technically.

What I meant was that since I am planning on changing my impeller and wear ring, what other items typically should be serviced while in there to optimize performance and reduce cavitation?

Also, is it possible to get the ride shoe off while on a trailer to reseal it and replace the neoprene pump to hull seal?

I would like to service the whole pump at once if possible.

 

[scooper77515]

Just to throw this out there, since we are talking about the price of impellers, I have a stock impeller from a 97 challenger in pretty good shape I would "give" away for the cost of shipping and packaging.

After switching to the skatrak swirl impeller, I consider the stock one to be junk, but if someone really needs one in a pinch, I will hand it over.

 

[pincusa]

Everything Snipe wrote can be done on the boat w/o removing the pump. If you want to do a full service on the pump, then you'll pull it off the hull. They're simple, so it's basically to check and replace the bearings. If you don't want to get that agressive, I'd look at the wiper seal that rides on the shaft behind the prop and put a new one in to keep the water out. Remember to use 518 when you put the new one in to keep the water out!

 

[lilngineer]

Floating ring - carrier seal

Well guys I got the pump all torn down today. Everything went pretty smooth with the exception of the driveshaft.

I just could not get the floating ring to slide on the shaft.

Question: has this part changed or superceded since 96?

I think it was so difficult to get apart because there were no rubber o-rings on the shaft grooves at all. There was a only metal ring clip in the rearmost groove of the shaft holding the floating ring back. It seemed to be locked on the clip. The only way I could get it to slide off the clip was by prying open the slits on the floating ring. I then slid the shaft out and saw that there were 2 rubber seals on the inside diameter of the ring.

The engine in my boat was professionally rebuilt by the previous owner so I imagine the shop set it up this way. It just doesn't seem to match what I see in the shop manual. Shouldn't all 3 o-rings be rubber? Shouldn't the floating ring "float" on the 2 smaller o-rings in the resrmost grooved and catch onto the 3rd larger one?

Any thoughts on this?

Thanks again,

Jason

 

[glenwhitt]

when i rebuilt, well replaced with new, my pump I made the change from the rubber oring to the clip. I prefer this as it is just better engineering and the reason why seadoo started using them in later years. For the least cavitation use a new carbon ring, inspect/replace the boot it attaches to, inspect/replace the metal collar that seats to the carbon ring (Do not remember the name), and replace the $5.00 neopreme seal from the pump to the transon.

When i replaced my pump I put new shaft, thrust washer, bearings, etc.. in the pump, used a skat trak impeller, and replaced everthing else to the motor except the drive shaft, had that inspected for any warpige though and it had none. Boat will stand on end when punched from dead stop.

I also play around with a newjet impeller that gets me another 3 to 5 mph top end but way slower getting there.

 

[glenwhitt]

oh ya. forgot to mention. Even with the clip there sould be two other orings on the shaft to seal this. Without it I am sure you are sucking a little air. every little bit counts

 

[lilngineer]

Is the metal clip part of a service bulletin? My dealer was looking it up and my 96 still calls for the rubber O-ring.

 

[timmyboy76]

driveshaft clip..

see what you mean. Looked up about 5 different boats and years, and all are call'n out for o-ring, but this is what "glenwitt" referring to..

http://www.parkeryamaha.com/search.aspx?find=driveshaft+clip

 

[glenwhitt]

thats the clip that replaces the large o ring the keeps the collar from sliding down the drive shaft BTW: Parkeryamaha is the bomb !

 

[Chester]

Yes, the clip is a replacement for the o-ring and for a good reason. I've seen several o-rings pop out of place and let the collar slide forward allowing water to flood the hull.
Also, as it wasn't mentioned yet, make sure you pressure test the pump after you put the cone on and before you put the oil in. Otherwise, if you happened to pinch the NEW o-ring or if the seal is leaking, you will catch it before you damage the whole pump.

Chester

 

[lilngineer]

Glenwhitt, when you've changed impellers, what pitch did you use?

Looks like the metal ring is the way to go. Thanks for the tip.