Coupler shaft not engaging - 05 SX230 Stbd Motor

[Pokeyt]

My main question - Why is my drive shaft not engaging with the splines in the coupler? Is it possible somehow its getting blocked from engaging the splines?

Mechanic was doing some work for me before the start of our boating season up here in the PNW. He let me know that he could not get the jet pump unit reinstalled, the shaft was getting stopped about ~1.5” from being fully seated. His diagnosis was bad coupler bearing. I checked the tunnel and could see all the way to the splines in the coupler, they all look to be in tact and i didn’t pull any metal out when I cleaned it out.

Today I pulled the coupler and the bearing is definitely bad, I’m ordering parts and will get it all pressed together at a local shop. But even after pulling the coupler and inserting the drive shaft into it I’m still not getting any engagement from the splines. Surely this isn’t all the bearing right? I even verified that the issue isn’t with the shaft by inserting the port shaft and had the same issue, so this is definitely something with the coupler.

Assume at this point I’m replacing the bearing, the shaft coupler & the rubber shaft coupling.

Shaft Coupler - 68Y-R1323-00-00​

 

[Beachbummer]

Was the pump ever locked up by debris ?

On our seadoo a sloppier spline mechanism would strip if the grease boot was not in place and full of grease, because the connection was somewhat looser than on the Yamaha.. There is no grease boot here, but I think the concept applies. If the bearing was overly loose the vibration might have worn out one side or both.

How about pictures of the splines in the shaft and the inside of the coupler???

 

[Cobra Jet Steering LLC]

there is a coupler with a rubber vibration dampener between the engine and the drive shaft so perhaps the rubber vibration dampener is missing look on the parts diagram

 

[Pokeyt]

Was the pump ever locked up by debris ?

On our seadoo a sloppier spline mechanism would strip if the grease boot was not in place and full of grease, because the connection was somewhat looser than on the Yamaha.. There is no grease boot here, but I think the concept applies. If the bearing was overly loose the vibration might have worn out one side or both.

How about pictures of the splines in the shaft and the inside of the coupler???

I could not get good photos of the splines but they appear to be in good shape, I did clean out the assembly and did pull a few small chunks of rubber out.

 

[Pokeyt]

there is a coupler with a rubber vibration dampener between the engine and the drive shaft so perhaps the rubber vibration dampener is missing look on the parts diagram

Will do - thanks!

 

[Cobra Jet Steering LLC]

Will do - thanks!

I posted a video on a previous comment that may help you

 

[Pokeyt]

https://www.yamahapartshouse.com/oemparts/a/yam/50039ed0f870021f60a1158b/jet-unit-2

I posted a video on a previous comment that may help you

thanks for the info, I really appreciate it!
I’m looking at the parts diagram and am not able to identify the rubber vibration dampener. What am I missing?

 

[Cobra Jet Steering LLC]

ok watch the video

 

[Pokeyt]

ok watch the video

ok watch the video

Watched the video twice and didn’t catch anything that would suggest a rubber damper. I’ll check it out again, maybe ask my wife to as well - she’s great at pointing out things I missed (suspect that’s a genetic trait all wives possess).

Thank you for the help!

 

[Beachbummer]

The rubber dampener is further away from the pieces in your video. It's a big rubber thing that goes on the rightmost part in your video. It's #1 in the parts fiche above.

I don't think that's your problem. The shaft should easily and fully fit into the coupler.

 

[Pokeyt]

The rubber dampener is further away from the pieces in your video. It's a big rubber thing that goes on the rightmost part in your video. It's #1 in the parts fiche above.

I don't think that's your problem. The shaft should easily and fully fit into the coupler.

Aha - thanks, I do have the rubber coupler damper but am replacing it while I’m at this. I am 100% sure that is not the issue at hand. I guess the female coupler end has to be stripped, both of my shafts match and seat just fine in the left engine. I’m going to order a new coupler and see if that does the trick.

 

[Beachbummer]

And as you inspect visually, do the shaft splines look similar in both shafts? Any visible/additional wear in the problem side?

 

[Pokeyt]

And as you inspect visually, do the shaft splines look similar in both shafts? Any visible/additional wear in the problem side?

No visible wear. Ran fine last time it was in the water. I’m thinking it has to be the shaft coupler that’s somehow worn or stripped. Both shafts seat just fine in port side. Both shafts have the same condition in stbd side.

 

[Beachbummer]

Last thought from me... User I've if those dentist picks or stuff wire, it other suitable tool to explore the coupler and see if there's some debris or deformation in there.

Just in case it's something that can be cleaned out?

Best of luck

 

[Cobra Jet Steering LLC]

Ok so I misunderstood your issue the splines are not going all the way into the coupler where the dampener is that is common on older boats the spline get small wear recesses in the groves so when you are pushing the parts in have someone rock the coupler left and right so the splines can clear the wear spots and move forward all the way or if you do not have any assistant grab the impeller and rotate the drive shaft to the left and to the right as you push the pump housing forward.
Also grease the splines to make it slide in past those spots easier.

 

[Beachbummer]

@Cobra Jet Steering LLC if you see his video, he has the whole driveline on a bench, out of the boat, and even then he cannot get the splines in. My last thought was checking and cleaning the coupler best as possible in case there some obstruction in there.

 

[Pokeyt]

Last thought from me... User I've if those dentist picks or stuff wire, it other suitable tool to explore the coupler and see if there's some debris or deformation in there.

Just in case it's something that can be cleaned out?

Best of luck

Thanks! I’ve

@Cobra Jet Steering LLC if you see his video, he has the whole driveline on a bench, out of the boat, and even then he cannot get the splines in. My last thought was checking and cleaning the coupler best as possible in case there some obstruction in there.

It is easier to inspect and clean out of the boat, that’s for sure. I am pretty confident that there are no obstructions. I totally felt like a dentist with a headlamp and the pick and the degreaser to try and get it all clean.

 

[Cobra Jet Steering LLC]

The splines on the shaft sitting on a bench ok If he does what I said the splined end of the driveshaft will go into the splines on the P T O and it will resist a bit but it will go all the way in Once it stops moving forward keep moving the impeller back and forth while eh pushes forward on it all of a sudden it will slide past the bad spot and go in .

 

[Pokeyt]

The splines on the shaft sitting on a bench ok If he does what I said the splined end of the driveshaft will go into the splines on the P T O and it will resist a bit but it will go all the way in Once it stops moving forward keep moving the impeller back and forth while eh pushes forward on it all of a sudden it will slide past the bad spot and go in .

And that did it! Learned a few things…
1) the amount of incremental movement to get it to grip was small.
2) news to me - the splines are directional. They grip when you turn the coupler/driveshaft clockwise but spin counter clockwise. Different than a vehicle.

I appreciate the help and info!