Logo
FULL SITE MENU

Made a mistake fitting new water pump on 2021 115 Vmax (Now has a whine at idle)

N

Nucad

Regular Contributor
I recently installed a new water pump (Used the Yamaha Kit) on my 115 Vmax and think I screwed it up. I watched a Youtube video that made no mention of protecting the bearing at the bottom of the drive shaft when I tapped on the new Impeller and the cap that holds it on. After that I watched another video where they took great care to not tap on the driveshaft. And pulling up while installing the top cap.

Anyone have a theory of how involved resolving this is? Might it go away with a few miles? IS it tearing the lower unit apart while operating? I have had success with many DIY Auto repairs, all the way to a motor rebuild, but in this case, I guess I F'd up just trying to be self sufficient. Opinions Greatly appreciated.
 
Are you talking about the plastic spacer and retaining ring that holds the water pump impeller down before installing the water pump housing? I have the exact same engine, 2021 VMAX 115 on our Bennington pontoon. I serviced my engine last year. I did have the slide hammer tool to remove the retaining ring and install a new one. The factory service manual makes no mention of having to pull up on the driveshaft while tapping down the retainer ring although I have seen videos that suggest to do that and others that made no mention of it. Is your VMAX a 20" or 25" shaft length? The 25" version does have a driveshaft center support bearing in the midsection that needs to be lubricated with grease to prevent whining and chirping of driveshaft spinning in that bearing. Basically taking a dallop of marine grease on the driveshaft and when it enters into that support bearing in the midsection it lubricates that bearing.
 
fitz73222 said:
Are you talking about the plastic spacer and retaining ring that holds the water pump impeller down before installing the water pump housing? I have the exact same engine, 2021 VMAX 115 on our Bennington pontoon. I serviced my engine last year. I did have the slide hammer tool to remove the retaining ring and install a new one. The factory service manual makes no mention of having to pull up on the driveshaft while tapping down the retainer ring although I have seen videos that suggest to do that and others that made no mention of it. Is your VMAX a 20" or 25" shaft length? The 25" version does have a driveshaft center support bearing in the midsection that needs to be lubricated with grease to prevent whining and chirping of driveshaft spinning in that bearing. Basically taking a dallop of marine grease on the driveshaft and when it enters into that support bearing in the midsection it lubricates that bearing.
Click to expand...
Hmmn, I think mine is the 20" Vmax as it sits on a smallish boat. From that parts diagram if I am looking at the correct one it appears a needle bearing sits at the bottom of the shaft. Getting the impeller over the new woodruff key was difficult and I ended up putting the old impeller on top and hit it quite a few times with a hammer to get it to sit on the shaft (Another mistake) Afterwards I theorise the woodruff key was not installed completely in it's recess which impeded installing the new impeller. Not sure what I can check at this point. Thanks for the reply.
 
The woodruff keys on Yamaha outboards are a PITA, especially in saltwater. Everyone else in the business figured out a different way to drive an impeller 50 years ago. They're way too tight and don't need to be. Everyone I've ever replaced, I would lap them on sandpaper till they were a light tap fit into the keyway. I doubt you damaged the bearing underneath, that whole pinion height stack is shimmed and torqued to a specification unless you were whaling on it with a sledge! Another Yamaha quirk is why does an impeller have to have retaining ring to set some kind of preload on a rubber impeller, that's what the housing does. I'm sure a wise Yamaha guy will set me straight on this. But, I do love my VF115 otherwise, sweet running engine. Can you post a video of the new whine?
 
fitz73222 said:
The woodruff keys on Yamaha outboards are a PITA, especially in saltwater. Everyone else in the business figured out a different way to drive an impeller 50 years ago. They're way too tight and don't need to be. Everyone I've ever replaced, I would lap them on sandpaper till they were a light tap fit into the keyway. I doubt you damaged the bearing underneath, that whole pinion height stack is shimmed and torqued to a specification unless you were whaling on it with a sledge! Another Yamaha quirk is why does an impeller have to have retaining ring to set some kind of preload on a rubber impeller, that's what the housing does. I'm sure a wise Yamaha guy will set me straight on this. But, I do love my VF115 otherwise, sweet running engine. Can you post a video of the new whine?
Click to expand...
I'll post a video in a couple of days when I am back with the boat on the lake. It seems smooth and normal when in gear, then whines when in neutral and idling.
 
Our goal is to stop your whining....
1755807160923.png
LOL
 
Last edited:
Yeah, how it self cured sitting in the dock all week is beyond me. I swear it made much more pronounced sounds a week ago when in neutral.
 
It's probably the amount of undefined pre-load you had on that plastic/metal tension ring that you smacked down and had the impeller tight against the wear plate and now has eased up. I do wish someone with higher knowledge level would explain its benefit to the water pump install or bearing lash, but I do know that after 46 years in manufacturing, OEM's don't add parts and cost for no reason. Carry on VMAX SHO to whine another day!! :)
 
fitz73222 said:
It's probably the amount of undefined pre-load you had on that plastic/metal tension ring that you smacked down and had the impeller tight against the wear plate and now has eased up. I do wish someone with higher knowledge level would explain its benefit to the water pump install or bearing lash, but I do know that after 46 years in manufacturing, OEM's don't add parts and cost for no reason. Carry on VMAX SHO to whine another day!! :)
Click to expand...
That is the plan. Thanks.
 
Back
Top