intermediate bearing replacement info.

[anmut]

So... is 2-3 pumps per season from the zirt fitting connected to the hose still correct?

 

[madtom]

Hi,

Current 2019 Yamaha FSH 210 owner and am currently replacing the intermediate bearings. I have about 145 hours on the boat. the previous owner used it in brackish water (Florida), docked on weekends, and then put back on the trailer on Monday mornings. Last year, the left engine drivetrain developed a persistent grinding/roaring noise, and its RPM was 400–500 lower than the right engine. I rebuilt both pumps, but the noise remained. Although there was no water leak, I noticed that the grease on the left side had a rusted, water-intruded appearance and was starting to drip from the front of the housing. Clearly, that bearing is worn out and has extra play.

I’ve received all the required parts from Boats.net and have rebuilt the bearing assemblies for both sides. Since replacing one is such a hassle, I decided to replace both at the same time rather than doing it piecemeal. The parts cost a bit more, but I’m confident that I’m getting genuine Yamaha components with authentic Japanese bearings instead of rebuilt ones from eBay. Interestingly, the same intermediate assembly is used in various models of Wave Runners and other jet boats from the past 20 years.

I added grease to the first bearing after assembly and when the pump got to where it felt full the extra grease was coming out on the back side of the seal around the intermediate shaft. Seal design and installation indicates it will keep water out but the grease will push past the seal lip. I also packed the bearings before putting the assemblies together.

I plan to post pictures of my progress as I move further along with the repairs.

Additionally, I added white 4200D sealant to the seams in the hull because the factory sealant around the pump shoe was deteriorating. I expect this will bring a slight performance boost once I finish reassembling everything.

While removing the engine mount bolts to lift the engine, I broke one of the bolts. The combination of saltwater, aluminum, and stainless steel creates a strong galvanic reaction—something I underestimated with my regular 3/8" ratchet. I ended up breaking the bolt, which now poses another challenge.

I also broke several drill bits while trying to start a pilot hole. I have now switched to a carbide-tipped/diamond bit (the type used for drilling granite), and I’m working slowly at a low speed of around 400–600 RPM to keep the bit cool. I’m hoping that the drilling will generate enough heat for the Kroil to penetrate the threads, making removal easier. Worst case, I might have to drill out the plate and install a Heli-Coil—a solution that’s eating into time I could be enjoying on the boat!

Has anyone else experienced a broken motor mount bolt? The bolt broke flush with the fiberglass, and I’m not keen on welding a nut on top. As mentioned, I’m slowly drilling to avoid complications.

I also learned that the Yamaha boat design features an aluminum plate embedded in the fiberglass where the motor mounts attach. This plate is pre-drilled and threaded for the motor mount bolts. Does anyone have a recommendation for an ideal anti-seize or thread locker when putting it back together?

Feel free to share your experiences or suggestions!

 

[FSH 210 Sport]

Hi,

Current 2019 Yamaha FSH 210 owner and am currently replacing the intermediate bearings. I have about 145 hours on the boat. the previous owner used it in brackish water (Florida), docked on weekends, and then put back on the trailer on Monday mornings. Last year, the left engine drivetrain developed a persistent grinding/roaring noise, and its RPM was 400–500 lower than the right engine. I rebuilt both pumps, but the noise remained. Although there was no water leak, I noticed that the grease on the left side had a rusted, water-intruded appearance and was starting to drip from the front of the housing. Clearly, that bearing is worn out and has extra play.

I’ve received all the required parts from Boats.net and have rebuilt the bearing assemblies for both sides. Since replacing one is such a hassle, I decided to replace both at the same time rather than doing it piecemeal. The parts cost a bit more, but I’m confident that I’m getting genuine Yamaha components with authentic Japanese bearings instead of rebuilt ones from eBay. Interestingly, the same intermediate assembly is used in various models of Wave Runners and other jet boats from the past 20 years.

I added grease to the first bearing after assembly and when the pump got to where it felt full the extra grease was coming out on the back side of the seal around the intermediate shaft. Seal design and installation indicates it will keep water out but the grease will push past the seal lip. I also packed the bearings before putting the assemblies together.

I plan to post pictures of my progress as I move further along with the repairs.

Additionally, I added white 4200D sealant to the seams in the hull because the factory sealant around the pump shoe was deteriorating. I expect this will bring a slight performance boost once I finish reassembling everything.

While removing the engine mount bolts to lift the engine, I broke one of the bolts. The combination of saltwater, aluminum, and stainless steel creates a strong galvanic reaction—something I underestimated with my regular 3/8" ratchet. I ended up breaking the bolt, which now poses another challenge.

I also broke several drill bits while trying to start a pilot hole. I have now switched to a carbide-tipped/diamond bit (the type used for drilling granite), and I’m working slowly at a low speed of around 400–600 RPM to keep the bit cool. I’m hoping that the drilling will generate enough heat for the Kroil to penetrate the threads, making removal easier. Worst case, I might have to drill out the plate and install a Heli-Coil—a solution that’s eating into time I could be enjoying on the boat!

Has anyone else experienced a broken motor mount bolt? The bolt broke flush with the fiberglass, and I’m not keen on welding a nut on top. As mentioned, I’m slowly drilling to avoid complications.

I also learned that the Yamaha boat design features an aluminum plate embedded in the fiberglass where the motor mounts attach. This plate is pre-drilled and threaded for the motor mount bolts. Does anyone have a recommendation for an ideal anti-seize or thread locker when putting it back together?

Feel free to share your experiences or suggestions!

As far as PM on the bolts is concerned my first thought is the white Loctite 572, it’s the same low yield thread sealant used on the large jet pump bolts that hold the pump assembly to the transom plate.

https://www.amazon.com/dp/B000O03DTQ?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1

That is such a drag that bolt broke off! Sounds like your slow going method is the best, I hope the bolt remnant will come out cleanly enough to re use the same hole, but if it doesn’t you’ve got plan be in the form of a heli coil to fix it.

Thanks for the info on the seal design and how some grease will push past. Kinda sounds like the previous owner did not grease the seals ?

Looking forward to your project pics.

 

[FSH 210 Sport]

How are you making out with the bolt extraction?

 

[Neutron]

What broke? The bolt that screws into the mount? If so just replaced the mount.
They are cheap, you can get a set of four for cheap money

 

[madtom]

How are you making out with the bolt extraction?

FSH,

Today, I finally managed to get a few uninterrupted hours on the repair. The limited access has made it impossible to pull the engine, so I'm working within the constraints presented by the situation—just dealing the cards I was dealt!

I'm using diamond-tipped granite bits at a conservative 600 rpm, which means the process is naturally going to take some time. My plan is to carefully attempt to extract what remains in the threads. However, if I end up stripping the plate entirely, I believe it would be more efficient to replace it with a new stainless steel helicoil.

For reference, I’ve attached a picture of the backside of the intermediate bearing—the very source of today's challenge.


Tom

 

[madtom]

What broke? The bolt that screws into the mount? If so just replaced the mount.
They are cheap, you can get a set of four for cheap money

One of the mount bolts that go into the hull

 

[Neutron]

One of the mount bolts that go into the hull

Oh, that sucks.
What will possibly happen is the nut that is set in the stringer will spin free. Had this happen a few times

 

[madtom]

So my diamond drill bit idea was successful while trying to remove what was left of a stubborn bolt. The approach proved successful, albeit with a few challenges along the way. In the process, I ended up using roughly eight 1/4-inch bits(thank you Amazon lol). The key was to go slow—taking about two hours to drill down far enough while regularly rinsing out the accumulated steel filings from the bit.

The primary goal was to drill down the center of the bolt—or as close as possible—ensuring that the bit stayed within the bounds of the bolt itself in for about one inch of depth. Once I achieved that, I switched to a left-hand 1/4-inch bit from an HF extractor kit. This allowed me to drill thru the rest of the bolt

After the initial drilling, I repurposed the diamond bit as a grinder to remove the remaining material from the bolt, up to the threads. To ensure accuracy, I threaded one of the middle bolts halfway in; this served as a gauge for the hole I had drilled. I then used a 19/64-inch left-hand bit from the HF kit to measure the diameter. The bolt hole ended up being approximately 7.4 mm, which was just sufficient to start off with an 8 mm tap. This precise outcome ultimately saved me from having to resort to the more complicated helicoil route.

I just hope that whatever is left of the bolt eventually makes it's way back to the area under the cleanout port so I can get it out . Stuff just rattling away makes me OCD. I still occasionally pull out a ziptie clipping that comes out thru the drain plug..... from when the factory put it together.... in 2018 .

This process not only demonstrated the effectiveness of the diamond drill bit method but also confirmed that with patience and careful control over the drilling and grinding actions, one can achieve a clean rethread even in challenging conditions.

 

[Neutron]

So my diamond drill bit idea was successful while trying to remove what was left of a stubborn bolt. The approach proved successful, albeit with a few challenges along the way. In the process, I ended up using roughly eight 1/4-inch bits(thank you Amazon lol). The key was to go slow—taking about two hours to drill down far enough while regularly rinsing out the accumulated steel filings from the bit.

The primary goal was to drill down the center of the bolt—or as close as possible—ensuring that the bit stayed within the bounds of the bolt itself in for about one inch of depth. Once I achieved that, I switched to a left-hand 1/4-inch bit from an HF extractor kit. This allowed me to drill thru the rest of the bolt


After the initial drilling, I repurposed the diamond bit as a grinder to remove the remaining material from the bolt, up to the threads. To ensure accuracy, I threaded one of the middle bolts halfway in; this served as a gauge for the hole I had drilled. I then used a 19/64-inch left-hand bit from the HF kit to measure the diameter. The bolt hole ended up being approximately 7.4 mm, which was just sufficient to start off with an 8 mm tap. This precise outcome ultimately saved me from having to resort to the more complicated helicoil route.

This process not only demonstrated the effectiveness of the diamond drill bit method but also confirmed that with patience and careful control over the drilling and grinding actions, one can achieve a clean rethread even in challenging conditions.

Nice work. Patience pays sometimes

 

[FSH 210 Sport]

So my diamond drill bit idea was successful while trying to remove what was left of a stubborn bolt. The approach proved successful, albeit with a few challenges along the way. In the process, I ended up using roughly eight 1/4-inch bits(thank you Amazon lol). The key was to go slow—taking about two hours to drill down far enough while regularly rinsing out the accumulated steel filings from the bit.

The primary goal was to drill down the center of the bolt—or as close as possible—ensuring that the bit stayed within the bounds of the bolt itself in for about one inch of depth. Once I achieved that, I switched to a left-hand 1/4-inch bit from an HF extractor kit. This allowed me to drill thru the rest of the bolt

After the initial drilling, I repurposed the diamond bit as a grinder to remove the remaining material from the bolt, up to the threads. To ensure accuracy, I threaded one of the middle bolts halfway in; this served as a gauge for the hole I had drilled. I then used a 19/64-inch left-hand bit from the HF kit to measure the diameter. The bolt hole ended up being approximately 7.4 mm, which was just sufficient to start off with an 8 mm tap. This precise outcome ultimately saved me from having to resort to the more complicated helicoil route.

I just hope that whatever is left of the bolt eventually makes it's way back to the area under the cleanout port so I can get it out . Stuff just rattling away makes me OCD. I still occasionally pull out a ziptie clipping that comes out thru the drain plug..... from when the factory put it together.... in 2018 .

This process not only demonstrated the effectiveness of the diamond drill bit method but also confirmed that with patience and careful control over the drilling and grinding actions, one can achieve a clean rethread even in challenging conditions.

Congratulations !!!

That was a long hard battle in what I’m sure was less than a comfortable position! Well done!