Pontoon Boat & Deck Boat Forum

I'm getting ready to put the boat away for the winter. The water pump is working but seems like it's getting weak.The discharge isn't spitting as much as it was... So I've decided to change it. Now here's the question... should I replace the whole thing or just the impeller? The whole kit is running 50 to 60 bucks, impeller is between 16 and 22. Not alot of money, but was just wondering why either way. I've been told to replace it every year. Oh guess I better tell ya what motor. 01 Mercury 90 ELPTO.

That sort of depends on the internal condition of the pump housing and impeller plate. If the plate has groves in it they yes.

If this is the first time the impeller has been changed, I would do the whole thing. Even if it's just been a few years since it's been changed, do the whole shebang.

The impeller will "wear in" to the housing and base plate, creating grooves and imperfections. These will cause early wear and possible failure on a new impeller.

We're only talking $30 bucks here. It's cheap insurance against getting stranded out on the water or damaging the engine from overheating.

I would wait until next spring before replacing it. If you do it now, the impeller will mold itself into the irregular shape of the housing from sitting all winter, which could also lead to failure. Better to have a fresh, crisp unit at the beginning of the season.

As a note, Mercury and all other manufacturers recommend changing the impeller once a year.

Our boat has about 350 hours and 5 years on it and I'm replacing the kit before our next outing with this full kit
http://www.simyamaha.com/Yamaha_Water_P ... xrbkit.htm

I've noticed in all the online vids and instructions, nobody mentions draining the lower end oil before doing it.
http://www.simyamaha.com/category_s/1992.htm
http://forums.floridasportsman.com/show ... a-Outboard

I'm most likely going to do that also but just thought it odd that it was never mentioned///

I always install the complete kit, better safe then sorry.

Drago wrote: I've noticed in all the online vids and instructions, nobody mentions draining the lower end oil before doing it.
/

Changing a water pump has nothing to do with the lower unit oil. It wouldn't be a bad time to change it while you are working on it, but it does not have to be drained to drop the lower unit.

I just took our boat in for winter storage, They also winterize the motor. When they do the motor they always remove the lower unit and do what ever is needed there .If the water pump is bad they automatically change it . If anything happens to it during the winter it's on them. Cheaper in the long run. Besides I'm to old to be messing with that stuff.

New pump ordered and should be at the house today. I'll be doing the whole kit this weekend.

Good luck its a piece of cake! Make sure and have help my lower unit dropped on the first smack We barely caught it!

PS put it in gear first!!!

curtiscapk wrote:PS put it in gear first!!!

Really? Everything I've read/seen so far indicate to make sure it's in Neutral.

This is a project I've not done yet since we just got our "new to us" boat last summer. The PO had the impeller replaced the previous year. So I was thinking of taking ion this project next Spring. So far the only thing I've not seen much detail about is disconnecting the shift shaft and pilot speedo tube that I see mentioned several places???

Technically it doesn't really matter.... you just have to make sure it is in either N or D on the lower unit before you try and push it back together or it won't line up. For us it was easier to do it with it in gear (D). you can change gears on the shift shaft with some pliers and a rag. It is just a pain in the ass to do it in the middle of the job.

The reason that I'm asking is that the drain plug for the lower unit oil is below the seam and six bolts that hold the bottom end to the main motor housing. It just appeared to me that all the lower unit oil would simply spill out when I pulled the bottom end off!!

Woody wrote:

Drago wrote: I've noticed in all the online vids and instructions, nobody mentions draining the lower end oil before doing it.
/

Changing a water pump has nothing to do with the lower unit oil. It wouldn't be a bad time to change it while you are working on it, but it does not have to be drained to drop the lower unit.

Kenneth,

LU oil is self contained to the lower unit. It will not spill out. The drain plug should be at the very bottom of your LU by the skeg. The screw in your pic is the fill hole.

And you probably have a seventh bolt under your trim tab.

Craig,
You're the man! Thanks for making it clear to my dull mind. The drain is down under the torpedo shaped thingy. And yes, there are two other bolts to remove through the anode. What's really stupid is I've drained the lower unit oil a few times but somehow forgot where the bottom plug was?!

Correction from the last post.....

There are THREE other bolts on the F225 to remove besides the 6 that are clearly visible!!! After the rubber plug is removed and the anode holding bolt is taken out ... there are TWO bolts under the anode. One is hard to see and hidden in a recess. I could not for the life of me figure out why the lower unit would not release - what can I say - I'm a complete dumb-ass?! The Sim Yamaha page http://www.simyamaha.com/category_s/1992.htm clearly illustrates on page 7 & 8 removing BOTH bolts.

If you've run your boat hard and ever had the overheat buzzer hit, I would recommend getting the full kit that includes the water pump housing.
http://www.simyamaha.com/Yamaha_Water_P ... 00comp.htm
Mine had gotten hot and the stainless steel pump housing had melted somewhat tightly to the pump housing. There was some clear evidence of the housing inner edges melting and flowing slightly. It was still usable but I had to work to extricate the old impeller housing from the pump housing.


Keep in mind that these parts and link illustrations are for our model and serial# Yamaha F225.

So the original question by Mitch really depends on how hard you have run your boat and the water pump service interval time. In my case it was really hard and 5+ years (350 hours) - well beyond the recommended time. In my defense, I'll just say that I've run in clean water, kept the engine flushed, and kept an eye on the pee stream closely. The overheat alarm has sounded 3 times in the last 6 months when doing extended idle runs. I found the old impeller was very well worn (permanent curve set in vanes) but the impeller housing had no scratches and looked very clean. We do not store our boat over winter as does Mitch but I'm not sure if either time is the wrong time to change the impeller in his case.