Changing Yamaha Jet Boat Pump (Duct Housing) Bearings and Switching to Oil Bath Lubrication

[FLJetBoater]

The x x x x on the bearing, is that an actual marking or the writing? I bought the sbt bearing rebuild pack before (was about same price as oem bearings) but they don’t have those marks on them

I've done as much research as I possibly can, and it seems that in these types of bearings (especially since they are horizontal and not vertical) that putting the text to the outside is simply a courtesy for when they have to be serviced, so, that's what I'm going with

PS. The bearings go on very easy if you freeze the shaft, can't say as much for the oil seals going into the duct. Going to try throwing the duct in the oven and see if that helps, otherwise I'm going to need a press for those.

 

[FLJetBoater]

So I got the pump bearings and spacer pushed on no problem. Barely took any force to get the bearings on and the spacer just floats (pressed) in between them. Packed the bearings with Yamalube Marine Grease A and filled the spacer with 20g of Epnoc as per the docs.

One important thing to note is that you can push the forward bearing on too far. It's important to measure the distance from the bearing to the next edge of the shaft (that's where the 0.91 inches come in, as we were discussing either here or in a different thread) as you're pressing it on so you don't go too far.

I also felt it was easier to assemble the pump before pushing it into the housing. Reason being if you push the forward bearing into the housing and put the spacer in, THEN the aft bearing, it seems that you're kind of breaking the rules about how to press in a bearing. You'd be pushing it on to the shaft and into the housing at the same time - so you'd need to be pushing on both races equally which I just don't have a tool to do. So, push onto the shaft with the inner race then will push into the housing with the outer race.

Had some problems with the oil seals though. I'm not sure if I pressed them in too hard, but the thicker one actually seemed to have split because when I turned the housing back over, part of it was loose. When I measured the distance from the seal to the edge it was right around the 7mm distance that it's supposed to be so I'm not sure what went wrong. Since it was loose I just stuck my finger in there and part of it came right out. The other half of the thick seal and the thin seal were still in there good. I pushed them out from the other side of the housing and I guess I'll have to order 2 more and try those again. They don't look like in the pictures they are supposed to really push together much, so the only thing I can think of is that I over pressed them.

 

[FLJetBoater]

New seals came today so got the rest of the pump put together tonight...

put the first seal in about half way, then the thicker seal and pushed them in together. Measured often until the 7mm clearance was reached.
Then pushed the shaft/bearings into the duct. This was pretty easy with the press but I actually bottomed out my press before the bearing was in all the way. I didn’t realize until I tried to put the cone on and there wasn’t enough clearance. Measured the shaft length from the duct to end and it was only 21 3/4. Adjusted the shelf on my press and pressed it in the remaining 3/4 inches. Washer/nut/oring/cone put on.
Oring/spacer/impeller put on.
It’s interesting that it’s harder to spin the shaft now that it’s all put together. Not sure if it’s the weight or just tighter. Will be installing it to the boat tomorrow and will be able to compare the one that’s on there after I take it out.

 

[jmargo]

Does anyone use the 518 anaerobic gasket maker between the housings like Yamaha calls for ?

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[mrcleanr6]

Just silicone here.

 

[FLJetBoater]

Does anyone use the 518 anaerobic gasket maker between the housings like Yamaha calls for ?

Amazon.com: Loctite 2203452 518 Gasket Maker Flange Sealant, 6 ml Tube, 1 Pack: Automotive

Buy Loctite 2203452 518 Gasket Maker Flange Sealant, 6 ml Tube, 1 Pack: Gasket - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

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When I rebuild my pump a few weeks ago I did use it.

 

[Mainah]

I pulled my pumps as part of a 5 year almost 300 hour overhaul. I have been referencing this thread and wanted to thank those whom have contributed as it has been a big help. FWIW my bearings are in great shape and no water intrusion. The impellers had a couple of very minor leading edge dings that I just filed down. The impellers also had some discoloration streaking from cavitation but no cavitation pitting. The wear rings had some very minor scarring. The pump/bearing housing had some minor organic growth and oxidation. The tunnels had quite a bit of growth/oxidation. The seals looked great. The intake grates had lots of paint coming off.

Super fine steel wool, ultrasonic cleaner, and simple green aircraft have been very useful in cleaning everything up. Have to say if you have the tools and a bit of know how not too bad a job. Also have to say given that we wakeboard and wake surf a lot things are holding up real well. Given that still makes 50 with just me and will hold 45+ mph with a full load of people I was not expecting to find anything major. I account the growth/oxidation to the fact that she goes on a lift after use in a fresh water lake so spray downs and washing are not nearly as frequent as if she were a trailer queen. I will post a thread of everything I decided to do at 5 years and nearly 300 hours once I am all wrapped up.

 

[Vedner19]

Is there a way to grease/oil the front bearing without taking the impeller off?

 

[Cobra Jet Steering LLC]

I remove the cone and add gear lube to the existing grease.
Here is the last results from adding some normal automotive gear lube in with the stock grease and resealing the original O ring on the pump cone My original 2014 pumps lasted from day 1 until I sold the skies, both had close to 900 hours of what most would consider hard riding, the impellers were also never touched but I did change to the nylon liners about mid way, here is my take on waterproof gear lube etc. If water gets in you have a problem either way but water is not supposed to get in and usually does not unless you remove the cone and don't seal the o ring. So with the pump and intermediate bearings waterproof is irrelevant , not true on wheel bearing grease as the bearing buddies have a tendency to let some water in so that would be a good thing in that application. Just my opinion based on my own experience.

 

[Bruce]

Is there a way to grease/oil the front bearing without taking the impeller off?

No. If you are removing the seals to grease the front bearing you might as well replace the bearings.

 

[mrcleanr6]

keep in mind that the pump is filled with epnoc grease which when it gets warm from use is supposed to flow like thick oil down into all the bearings keeping them lubed. having to disassemble the the housing just to grease the bearings is not needed.

 

[Vedner19]

So you’re adding automotive gear lube to the existing Yamaha Epnoc lube? It calls to fill the cone 2/3 full with the Epnoc so I just add the automotive gear lube to the 2/3 amount of Epnoc? If not, what would the ratio be? Thanks!

I remove the cone and add gear lube to the existing grease.
Here is the last results from adding some normal automotive gear lube in with the stock grease and resealing the original O ring on the pump cone My original 2014 pumps lasted from day 1 until I sold the skies, both had close to 900 hours of what most would consider hard riding, the impellers were also never touched but I did change to the nylon liners about mid way, here is my take on waterproof gear lube etc. If water gets in you have a problem either way but water is not supposed to get in and usually does not unless you remove the cone and don't seal the o ring. So with the pump and intermediate bearings waterproof is irrelevant , not true on wheel bearing grease as the bearing buddies have a tendency to let some water in so that would be a good thing in that application. Just my opinion based on my own experience.

 

[Cobra Jet Steering LLC]

Here is what I do. FIRST inspect the inside of the pump with the cone off and look for evidence of water if you have water in there you need to rebuild the pump , if it looks good I have the pump aimed up with the drive shaft down I use a dental syringe and put in gear lube by way of the syringe end I usually put in 3 or 4 syringes full probably 3 or 4 oz. total I do not remove the original grease. So this will mix with the grease and make it more fluid and sling around better inside. Clean the o ring on the end cone and use some silicon gasket sealer when put the cap back on. Also if you hold the drive shaft in one hand and spin the pump housing with your other hand you can feel if it turns smooth or if it has resistance before you disassemble it ,if it resists turning rebuild it. If you rebuild it I would replace about 1/4 of the grease with gear lube.. I also use gear lube on the intermediate bearings in place of using a deadly grease gun. I put it in the housing the same way by using a plastic dental syringe and I gain access by removing the grease fitting I also use line trimmer string to check the grease in the housing so I know if there is any water in it before I add the gear lube. If it has water in it you will need to replace it.

 

[Vedner19]

Ok thanks. I had no water in one and about 10 drops in the other. Both impellers move freely. The one without water is perfectly silent. The one that had a little water barely has a sound when spinning the impeller. If I were to ‘rebuild’ these what all would be needed? Just the front and rear bearings, right? Anything else that would have to be ordered besides the bearings? I already have 2 tubes of Epnoc and 2 new cone o-rings.

Would you rebuild these considering what I’ve mentioned? I’m tempted to try injecting gear lube and letting it soak in.

Here is what I do. FIRST inspect the inside of the pump with the cone off and look for evidence of water if you have water in there you need to rebuild the pump , if it looks good I have the pump aimed up with the drive shaft down I use a dental syringe and put in gear lube by way of the syringe end I usually put in 3 or 4 syringes full probably 3 or 4 oz. total I do not remove the original grease. So this will mix with the grease and make it more fluid and sling around better inside. Clean the o ring on the end cone and use some silicon gasket sealer when put the cap back on. Also if you hold the drive shaft in one hand and spin the pump housing with your other hand you can feel if it turns smooth or if it has resistance before you disassemble it ,if it resists turning rebuild it. If you rebuild it I would replace about 1/4 of the grease with gear lube.. I also use gear lube on the intermediate bearings in place of using a deadly grease gun. I put it in the housing the same way by using a plastic dental syringe and I gain access by removing the grease fitting I also use line trimmer string to check the grease in the housing so I know if there is any water in it before I add the gear lube. If it has water in it you will need to replace it.

 

[Cobra Jet Steering LLC]

Give it a try and see it may surprise you just be sure the o ring gets cleaned and sealed the gear lube keeps the seals lubed better than just grease and that may help.

 

[mrcleanr6]

you will also need all new seals. if there is no water in the one then that one is fine. if you are in fact getting water in the other then that one needs a rebuild. adding grease or gear lube wont help keep the water out. typically you wont see drops of water as it will mix into the grease and make a frothy mess. sometimes under pressure. be sure the drops just didnt get in there from the housing when you pulled the cone.

 

[Cobra Jet Steering LLC]

With a little ingenuity you should be able to replace the drive shaft seal without pulling the impeller depends on your imagination and mechanical aptitude , all while knowing if you have an issue you can always remove the impeller and drive shaft. I would use a long screw in the seal and then grab it with a vice grip and tap it up out of it's seat.
Clean the drive shaft and carefully lube it and slide the new seal down into place after you removed the old one, use a flat piece of metal larger than the seal with a hole cut in the center to clear the drive shaft and carefully tap the metal to seat the seal in place as long as the metal is larger than the seal you won't be pushing the seal in too far as the Metal will prevent that.
You could probably locate a large flat washer of sufficient size to do the job.
Once you have the seal in place and the washer on top of it you can use a piece of pipe and slide it on the drive shaft, hit the washer with the pipe to seat the seal like a reverse slide hammer.

 

[madtom]

Pulled the pumps as part of my pre-season maintenance. planning on converting to oil bath as that will make my maintenance a little less user intensive. I am replacing seals and bearings as this boat started life with PO in brackish/salt. Port pump was no issues but now has new seals and bearings so starting from a blank slate. Starboard had shifted the shaft a tiny bit back and the seals were toast.... not a lot of water in the grease but it was getting in there.... what was left of the inner seal on the shaft kept most of it out....there were mineral deposits all over what was left of the front seal and the bearings were just a little rough. glad I caught this in time. used a brass brush to clean most of the deposits out but will need to clean it out again tomorrow before assembly.

 

[FLJetBoater]

Pulled the pumps as part of my pre-season maintenance. planning on converting to oil bath as that will make my maintenance a little less user intensive. I am replacing seals and bearings as this boat started life with PO in brackish/salt. Port pump was no issues but now has new seals and bearings so starting from a blank slate. Starboard had shifted the shaft a tiny bit back and the seals were toast.... not a lot of water in the grease but it was getting in there.... what was left of the inner seal on the shaft kept most of it out....there were mineral deposits all over what was left of the front seal and the bearings were just a little rough. glad I caught this in time. used a brass brush to clean most of the deposits out but will need to clean it out again tomorrow before assembly.
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Nice catch! Assuming you had to press the shaft/seals out of the housing to do all this work and reassemble?

 

[madtom]

Nice catch! Assuming you had to press the shaft/seals out of the housing to do all this work and reassemble?

Yeah Harbor Freight / Northern tools are my close friends. My medium press gets used regularly. Used it on BMW suspension parts last week. You can never have too many tools or spares for things that break and are often on back order. Plan on cleaning the housing and polishing the seal area on the driveshaft with 3k and 5k pads before putting it back together.

I may have to get a spare driveshaft and impeller to put on the shelf for a rainy day. Babbits was saying Yamaha backorder until mid May-June for these impellers and shafts.
I have always had spares for the jet skis and used them at least once a season... teenagers are good at running items thru the pump on a regular basis.