1991 650 Waverunner VXR- Taking on water

[jedbmw]

Last Post: Rebuilt the Carb, unit working perfectly again. Until…
Now I started taking on a significant amount of water into the hull.
I flipped the unit upside down on the beach to inspect hull. hull looks fine.
Plug is in.
What is the best method to troubleshoot this problem?
What are the more likely causes?
Thanks jed

[Technical Support]

Re: 1991 650 Waverunner VXR- Taking on water

put the ski on a trailer, tip the front up a bit and put water in the hull with the garden hose just over the drive shaft, see if you see a leak, if not start the ski and check again.

[jedbmw]

Re: 1991 650 Waverunner VXR- Taking on water

Thanks for the response.
Step 1: I ran the ski with garden hose connected for cooling/flush and checked for leaks in the hull. All Good, no leaks.

Step 2: I filled the hull slowly with water, no leaks were observed until the water level was at the drive shaft bearing level “drive line” . Water leaked though the drive shaft. Leak found! Problem was bad shaft bearings seals.

Ordered the driveline repair kit. Removed the old bearing and discovered the bearing lip seals were totally shot, and that the coupler shaft was worn down “damaged” beyond use.

Ordered a new coupler shaft.
With the couple shaft and driveline bearing in hand, the question I have now is where do those 2 o-rings shipped with the driveline repair go?

I do not see a grove fro the o-rings on the coupler shaft or the drive shaft for those o-rings.
When I disassembled, I did not see them. thanks again.

[jedbmw]

Re: 1991 650 Waverunner VXR- Taking on water

I found where the o-rings are installed; they go into inside the coupler shaft.

Next Problem:


The coupler shaft into the bearing housing is a very tight/snug fit.



How do (should ) I press in (or “press through”) the shaft coupler through the bearing housing?
How will I know when the shaft is installed all the way?


I tapped the coupler shaft into the bearing housing using a rubber mallet and I was able to move it along and through about 3/16” (protruding through the opposite bulkhead side)



I am concerned about damaging my new parts.
Should this be that snug? Keep tapping?
thanks jd.

[jedbmw]

Re: 1991 650 Waverunner VXR- Taking on water

To wrap this up for others ….

I had discovered the hard way*** the coupler shaft must be “pressed in” through the bearing assembly.

It is called an “interference fit ”. AKA Very tight, therefore the coupler shaft must be pressed through the bearing with a hydraulic press.

*** I damaged my new driveline bearing lip/oil seal on the bulkhead side on my first attempt. I was however successful on the second attempt. Here is how I did it, and what not to do

Google the internet to locate the Yamaha parts breakdown diagram of the driveline bearing assembly.

Powersports web page had the diagram.


Study the internals of the driveline bearing assembly diagram .

Note there are two lip/oil seals on the bulkhead side. Inner and outer. Don’t put any pressure these seals!

Note the main bearing (with the interference fit) sits behind both the inner/outer oil seals and this main bearing is secured to the assembly housing with a large “C” Clip: Therefore, the assembly housing must be used as the solid backing while pressing in the couple shaft. Do not put pressure on lip/oil seals!

DO NOT place a deep socket on the outer lip seal while driving the coupler shaft through the bearing assembly. You will damage the outer lip/oil seal as I did. Use the housing as a backing.

DO NOT hammer the coupler shaft through the assembly. Use a hydraulic press or a Bottle Jack.
I purchased a “20 ton” Bottle Jack at Lowes (Kobalt Brand). About $45 on sale.

Luckily, I was able to purchase (as a pair) the inner and outer lip/seals to replace what I had damaged. About $25 with shipping.

I positioned the Bottle Jack horizontally within a 36” concrete cinder block door opening in my basement. I cut a 4”x4” wood post to proper length. See Diagram Below:

[WALL]=======4X4========BottleJack::CouplerShaft::Bearin gAssembly::EndClamp[WALL]

To support the Bearing Assembly allowing the shaft to slide through…
I used the `End Clamp` of a York dumbbell bar weight set. You could use something else that fits and serves the same propose.

I positioned the `End Clamp` to align with the centerline of bearing assemble. To hold it in place, I used masking tape to hold the End Clamp/bearing Assembly in position.

Key Point : Use the bearing carrier/housing as a backing (Steal on Steal) while pressing in the coupler shaft. DO NOT touch the rubber Lip/Oil seal. My dumbbell `End Clamp` was a perfect/nice fit for this purpose.

Study carefully the old coupler shaft and the old bearing housing. Take a few measurements on how far the new coupler shaft must be pressed through.

Study the changes of the diameter of the new coupler shaft. Note the diameter increases with a slight ridge to prevent the shaft from going in to far into the bearing housing.

Hold your breath: Now press (measure) the coupler shaft slowly until you hit the ridge. Measure and compare as you go.

Very easy/smooth with the 20 Ton Hydraulic Bottle Jack! No need to (warm bearing) (freeze shaft).

This job was more challenging than I anticipated. I did make a mistake; I learned on my own and was able to recover. I lost about a month of valuable summer waiting on parts (separate orders).


Bearing Assembly: ~$120
OEM Coupler Shaft: ~190
20 Ton Bottle Jack ~$45
Replaced Damaged Lip Seals ~$25
--------------------------------------------
Total: ~$380

In my opinion, the Couple Shaft and the Bearing should all come preassembled (pressed in) as a unit. Recommend SBT offer this to its customers.

At a minimum, some instructions or guidance should be provided with the driveline repair kit. Another option is to take your old and new parts to an auto shop (with a press) and have the shop press it in for you.

Finally, if you have an older ski, this job definitely needs to be done. Perform a leak check ASAP as described in the post. If the leaks through the shaft, the seals/shaft are shot. Guaranteed the lip seals (and shaft) and now the bearing are all worn by now.
Replace the Shaft and driveline bearing together as a pair. Recommend doing this job over the winter.

Good Luck.