Nose cone greasing and other things (picture heavy)

[anmut]

250 hours on my motors and I decided I was well overdue to pull the pumps and grease the nose cone bearings. I believe this is something that's supposed to be done every 100 hours. Took about two hours from start to finish and I went really slow trying to be methodical as possible. Some surprises and lessons along the way:

• This was my first time ever pulling my pumps out and I'm glad I did it with a full array of tools available and not attempting it at a boat landing after sucking up a rope. The bolts for both pumps were really tight and I had to use an impact on two of them on the port pump.
• Both cones were about 1/3 full of grease. STBD pump cone had a few drops of water in it. I was happy to see that, even with 250 hours on the original grease, the bearings were still in fine shape.
• No chips were found on my impellers but it appears I have some (or at least what I believe to be) burn on the bow side of the impellers. I **think** this is from surfing with a ton of water weight and the impellers creating super heated water on the edges that it's actually melting the metal. It's interesting to note that I've never felt any performance degradation on either pump. Port pump had the burns on all three blade and STBD only on one. Either way, I'll be replacing them at the end of the season.
• I found the easiest way to reline the pump splines back into the engine was to hold the pump assembly with my left hand and turn the impeller (while reaching around the back) and slightly turn the impeller until I could feel it line up, then slightly pushing the shaft into the splines to get it to set.
• I FOUND THE RATTLE in my pumps too - the damn anode bracket was broken my STBD pump - that's been driving me nuts for a long time, I can't believe I never noticed it before. If you have a rattle in your pumps at low speed, check your brackets. @Cobra Jet Steering LLC I believe these offset brackets are from your kit - how much are replacements?
• Parts I used for my 2020 with 1.8l:
  • Epnoc Jet Pump Grease for nose cones (two pack)
  • Yamaha Molybdenum Disulfide Grease for the shaft splines
  • Yamaha O-Rings for nose cone

Pump pulled, bearings exposed, and old grease:




Burning/melting on impellers:




Broken anode bracket

 

[kgower]

250 hours on my motors and I decided I was well overdue to pull the pumps and grease the nose cone bearings. I believe this is something that's supposed to be done every 100 hours. Took about two hours from start to finish and I went really slow trying to be methodical as possible. Some surprises and lessons along the way:

• This was my first time ever pulling my pumps out and I'm glad I did it with a full array of tools available and not attempting it at a boat landing after sucking up a rope. The bolts for both pumps were really tight and I had to use an impact on two of them on the port pump.
• Both cones were about 1/3 full of grease. STBD pump cone had a few drops of water in it. I was happy to see that, even with 250 hours on the original grease, the bearings were still in fine shape.
• No chips were found on my impellers but it appears I have some (or at least what I believe to be) burn on the bow side of the impellers. I **think** this is from surfing with a ton of water weight and the impellers creating super heated water on the edges that it's actually melting the metal. It's interesting to note that I've never felt any performance degradation on either pump. Port pump had the burns on all three blade and STBD only on one. Either way, I'll be replacing them at the end of the season.
• I found the easiest way to reline the pump splines back into the engine was to hold the pump assembly with my left hand and turn the impeller (while reaching around the back) and slightly turn the impeller until I could feel it line up, then slightly pushing the shaft into the splines to get it to set.
• I FOUND THE RATTLE in my pumps too - the damn anode bracket was broken my STBD pump - that's been driving me nuts for a long time, I can't believe I never noticed it before. If you have a rattle in your pumps at low speed, check your brackets. @Cobra Jet Steering LLC I believe these offset brackets are from your kit - how much are replacements?
• Parts I used for my 2020 with 1.8l:
  • Epnoc Jet Pump Grease for nose cones (two pack)
  • Yamaha Molybdenum Disulfide Grease for the shaft splines
  • Yamaha O-Rings for nose cone

Pump pulled, bearings exposed, and old grease:
View attachment 224212
View attachment 224218
View attachment 224219

Burning/melting on impellers:
View attachment 224215
View attachment 224216
View attachment 224217

Broken anode bracket
View attachment 224214
View attachment 224213

Good post.

 

[Babin Farms]

Cavitation is causing your impeller blade to look like that. I see it in the pumps I work on daily.

 

[anmut]

Cavitation is causing your impeller blade to look like that. I see it in the pumps I work on daily.

I've never noticed any cavitation *except* when at WOT and surfing with a full load, so that must be the culprit. Do you think upgrading to a different impeller, or duel impellers, would help with the issue?

 

[David Martin]

I'm getting ready to pull my pumps this weekend 2013 SX240 I fairly sure I won't find what you are seeing..........WOW you are pushing your stock equipment to and in some cases, past it's design limit. The Epnoc grease looks normal color in the middle but around the edges appears to have been burnt from heat past it's Drip Point.

Epnoc has a drip point of 190C or 383F go too far past this and it burns like around the edges I see in your cone. It does make sense as hard as you are pushing your jets that the bearings would be hotter than most of us see. Also was their water intrusion in your bearings it looks wet?

My 2013 takes Type A EP Yamaha grease in my cone and bearings and even in the midshaft bearings. Type A has a 475 F drip point..... I don't think it would matter on my boat Type A or Epnoc....... newer boats switched to Epnoc in the cone. Just trying to rap my head around your pushed to the limit bearing temps............and if you might not be better off with a higher drip point temp grease............I can say any grease or oil that gets burnt loses its ability to lubricate.

Good luck and keep us posted!

 

[Babin Farms]

I've never noticed any cavitation *except* when at WOT and surfing with a full load, so that must be the culprit. Do you think upgrading to a different impeller, or duel impellers, would help with the issue?

The cavitation is so minimal that you’re not noticing it(fairly common). It’s sucking air from somewhere, maybe the intake grate needs new sealant, dunno. At this point I would keep running it the way it is, just check things over and try one fix at a time so you know what actually “fixes” it.

 

[FSH 210 Sport]

I've never noticed any cavitation *except* when at WOT and surfing with a full load, so that must be the culprit. Do you think upgrading to a different impeller, or duel impellers, would help with the issue?

Perhaps it is an optical illusion, but I’d check the gap between the impeller and wear ring, especially in the area where there is wear on your impeller.

In theory the dual or twin screw impellers should eliminate cavitation. I’d move forward as @Babin Farms suggested.

 

[anmut]

I'm getting ready to pull my pumps this weekend 2013 SX240 I fairly sure I won't find what you are seeing..........WOW you are pushing your stock equipment to and in some cases, past it's design limit. The Epnoc grease looks normal color in the middle but around the edges appears to have been burnt from heat past it's Drip Point.

Epnoc has a drip point of 190C or 383F go too far past this and it burns like around the edges I see in your cone. It does make sense as hard as you are pushing your jets that the bearings would be hotter than most of us see. Also was their water intrusion in your bearings it looks wet?

My 2013 takes Type A EP Yamaha grease in my cone and bearings and even in the midshaft bearings. Type A has a 475 F drip point..... I don't think it would matter on my boat Type A or Epnoc....... newer boats switched to Epnoc in the cone. Just trying to rap my head around your pushed to the limit bearing temps............and if you might not be better off with a higher drip point temp grease............I can say any grease or oil that gets burnt loses its ability to lubricate.

Good luck and keep us posted!

With surfing and a full load of people I’d say for sure those motors are being pushed to the limit. 250 hours on the boat and I bet there’s 100 hours of water sports in that time.

 

[anmut]

The cavitation is so minimal that you’re not noticing it(fairly common). It’s sucking air from somewhere, maybe the intake grate needs new sealant, dunno. At this point I would keep running it the way it is, just check things over and try one fix at a time so you know what actually “fixes” it.

Will do.

 

[Cambo]

I've never heard cavitation in the many hours of surfing on my boat. In fact, I go full throttle to form the wave and then back off the throttle (or Ride Steady does) to maintain...

With surfing the cavitation tone is not as noticeable like when you suck up debri but I can definitely hear it or feel it in the vibration while surfing. When you replied my immediate thought was to tell you to look at your impeller edges. The twin screws do help with this but I can still feel it. While surfing it goes away once the throttle is backed off and the surfer is up and riding. The twin screws have better thrust that allows you to drop the RPM lower.

 

[Julian]

Perhaps it is an optical illusion, but I’d check the gap between the impeller and wear ring, especially in the area where there is wear on your impeller.

In theory the dual or twin screw impellers should eliminate cavitation. I’d move forward as @Babin Farms suggested.

I was going to say the same thing. It LOOKS like the gap is larger on the impeller with the cavitation. Keep in mind that cavitation is caused by pressure differentials and not air being injested. Having too much gap there could be causing it....but I'm no fluid dynamics expert! Id definitively be considering a new wear ring if you are considering new pumps. Check the gap to the tolerence specs.

 

[anmut]

I was going to say the same thing. It LOOKS like the gap is larger on the impeller with the cavitation. Keep in mind that cavitation is caused by pressure differentials and not air being injested. Having too much gap there could be causing it....but I'm no fluid dynamics expert! Id definitively be considering a new wear ring if you are considering new pumps. Check the gap to the tolerence specs.

More good thoughts, thanks! Any idea on how hard that wear ring replacement is - does that need to be pressed in/out?