Impeller Replacement

[b1gdog83]

I have a 2017 (8 months old) 200hp with 160 hours on it. I've heard different opinions on when I should replace the Impeller. How long can I expect to go before I should replace it?

[artdf175]

I have heard no more than 200 hours
I believe your manual will indicate 100
If your engine is under warranty, I would go with the maintence schedule
Art

[b1gdog83]

The service manual actually says to inspect the "Water Pump Impeller" every 200 hours and replace it every 300 hours or 36 months. Did they recently change this on the newer motors because most people say they are changing it every 200 hours but the manual indicates to change every 300 hours.

[Moonlighter]

One of the reasons for every 200 hours is that if you dont drop the leg at least every 2 years (preferably annually) then the bolts seize up and you then have big problems. Plus you grease the drive shaft splines which is also sensible maintenance.

And if you are going to drop the leg, then the cost of a water pump kit makes sense to do it at the same time.

[b1gdog83]

So even in my case where ill be hitting 200 hours and and it's only about 10 months old? You don't think I can do it every 300 hours like the manual says?

[Harper]

I purchased my DF150 new 9 years ago, yet I don't have quite 300 hours on the motor. So I obviously don't put the number of hours on the water as many who post here. But there are a few things that I do because of that, and I would like to point them out now. Because I put so few hours on the motor, I use a different schedule for maintenance. I base it on calendar time, rather than engine hours. Every year I change the oil and gear lube. I use Amsoil synthetic for everything. I try to run the motor on the muffs every couple of weeks. And when I do, I let it run for at least a half-hour after reaching normal operating temperature of 150°. I do this both to lube it well internally and to make sure the thermostat has opened and all water passages have been flushed. I have a 60 gallon gas tank which I keep full of non-ethanol gas that's been treated. I change the fuel filter/water separator every two years, I have an onboard battery charger/maintainer that remains plugged in all the time. I have NEVER had a single problem with the motor. It has never failed to start on the first crank. AND.... I drop the lower unit once a year. for the reasons that Moonlighter pointed out.

So the main thing I want to emphasize in Moonlighter's response is to remove the bolts to the lower unit periodically. The impeller should last the 300 hours easily, assuming you haven't run aground or through the shallows where you would pick up sand or other abrasives. But based on real time, not engine hours, you should remove every bolt that attaches the lower unit to the driveshaft housing and lube it with anti sieze compound. Those bolts WILL sieze in the aluminum and will be downright expensive to fix. Moonlighter's advice to also grease the driveshaft splnes is solid advice. The splines will also tend to sieze over time and it will thus be difficult to remove the lower unit when you do need to rebuild the water pump.

So my advice would be to drop the lower unit yearly to take care of those things I mentioned, and if you feel so inclined, check your water pump while you have access to it, whether you've got 100 hours or 300.

[b1gdog83]

I appreciate all the advice. I've been convinced to pull the lower unit and change the impeller when I reach 200 hours which I have 40 more hours to go. I've been told to use silicone sealant around the gear case and drive shaft housing.mating area. Is this the normal thing to do?

[Harper]

I've heard that before. But haven't read it in any manual that I have, and have never used any sealant there. It's never appeared to me that it ever had any sealant to begin with.

[wilbur1]

I think I seen it in the manual.

[Hoosmatroos]

Normally there is no sealant in that area. The sealant will get it tough to get the lower end off next time. There is no logical reason to put sealant in there in my opinion. There are also drain holes to let the water escape so why put sealant on the mating area?

Use some grease or anti seize on the bolts and dowel pins so you can easily remove them easily the next time.

[Bamahemi]

I have a 2014 300 DF, dropped the lower once a year to inspect, use Teflon marine grease on the shaft, bolts etc. just did the impeller at 4 years 200 hours. Had a few times where I pulled boat out of water with motor running🤦🏼♂! Impeller came out fine. Also have changed the direction for the prop rotation. No dry rot, cracking or melting noted, just a wrinkle from being used.

[tnadeau]

Why not purchase the Suzuki Service Manual for your expensive outboard? You'll have all the answers you'll need right there. A model specific Service Manual is one of the best tools in your box! While you're at it get the Parts Catalog too. The folks sat the parts counter will be impressed when you order by part number they don't have to look up. :-)