How Often Do You Change Your Impellar?

luvmystratos · Post by **luvmystratos** » Tue Nov 01, 2011 6:34 am

Just curious, how often do some of you change your Impellar? Do you change it when you do your 20 Hour Service or when you do you 100 Hour Service or do some of you change it every year whether it needs it or not? I have a Mercury 225 Pro XS and I change it every year regardless; don't want any Water Pressure issues when I am moving from point A to B. I know Evinrude has that 3 year "no maintenance" clause with their motors but is it true and how about Yamaha Engines?

Terry Smith · Post by **Terry Smith** » Tue Nov 01, 2011 7:22 am

My 2004 150 optimax has to be done between 75 and 100 hours. Don't know about any other engines

mark poulson · Post by **mark poulson** » Tue Nov 01, 2011 9:47 am

I have mine changed at my annual service. Cheap insurance.

Gator · Post by **Gator** » Tue Nov 01, 2011 11:12 am

Yep - annually along with the lower unit oil and a complete motor once over.

jloo283 · Post by **jloo283** » Tue Nov 01, 2011 12:18 pm

Terry Smith wrote:My 2004 150 optimax has to be done between 75 and 100 hours. Don't know about any other engines

Why kind of issues would you notice if you didn't follow this exact schedule? I've got the same setup, approaching the 80 hr mark. Not that I'm seeing any issue, just would like to get more info from your experience as a precautionary measure. Thanks.

James

mark poulson · Post by **mark poulson** » Tue Nov 01, 2011 2:27 pm

I would call my boat mechanic, and see what he says. Hopefully, he's a Mercury authorized mechanic, and honest. He can tell you much better what the risks are, and how to avoid them.

I'm no boat mechanic, but I'd guess, if you're lucky, you'd notice dropping water pressure, so you'd know to change it before it goes bad.
If you're not lucky, you won't notice, and your motor could overheat, and that can lead to bad things. Spell that expensive.
If you have a way to monitor your water pressure, and you actually do it, you might be able to stretch it. My buddy changes his impeller every two years, but he doesn't fish every weekend. I do, so I don't want to take that kind of a chance. His Opti is a 2004, and I have more hours on my 2008 than he does, so you can see he doesn't use his boat as much as I do.
A failure at high RPMs sounds bad to me.

jack morris · Post by **jack morris** » Tue Nov 01, 2011 2:58 pm

Not only can you fry a motor but even if you change it out before that it can do damage. If the impeller is old it can break off pieces and plug up the water passeges and I know first hand what a pain that is to clean-up. I had to tear my old johnson down three times to clean all the pieces out.

birdi23nls · Post by **birdi23nls** » Tue Nov 01, 2011 3:25 pm

If you have a newer motor like the 2004 Optimax or whatever it was you said you had...the motor overheating and blowing should not be an issue. All of the motors have alarms on them to warn you of such problems. If it gets to that point, I was told that the motor wont even start (someone let me know if i'm wrong on this). I have had my boat now for two years going on three, and I have not changed mine. I don't put a lot of hours on the motor, but keep thinking that I should change the impeller soon. I go in to the mechanic and tell them what my water pressure reads (high teens to low twenties on plane) and how many hours are on the boat and they keep telling me to hold off. So far, so good...but if my water pressure doesn't start to decline soon, I'm probably going to change it anyway.

Larry Hemphill · Post by **Larry Hemphill** » Tue Nov 01, 2011 9:37 pm

I feel the key is how often the motor is used. I usually change mine every 2 years because my boat is always in use which keeps the impeller from becoming brittle. Motors that sit for months on end have more trouble with broken impellers.

myrtle · Post by **myrtle** » Wed Nov 02, 2011 12:40 am

jack morris wrote:Not only can you fry a motor but even if you change it out before that it can do damage. If the impeller is old it can break off pieces and plug up the water passeges and I know first hand what a pain that is to clean-up. I had to tear my old johnson down three times to clean all the pieces out.

I lacked the knowledge of the rubber impeller until it was to late. the engine got so hot that the flywheel put a good blister on my arm. Impeller replacement is my number 1 priority every spring. For those of you folks that do not have a temp gauge or at least an alarm I recommend replacing the thermostat too!

eagle123777 · Post by **eagle123777** » Wed Nov 02, 2011 6:13 am

luvmystratos wrote:Just curious, how often do some of you change your Impellar? Do you change it when you do your 20 Hour Service or when you do you 100 Hour Service or do some of you change it every year whether it needs it or not? I have a Mercury 225 Pro XS and I change it every year regardless; don't want any Water Pressure issues when I am moving from point A to B. I know Evinrude has that 3 year "no maintenance" clause with their motors but is it true and how about Yamaha Engines?

every year is a good idea and i have done that, but my merc mechanic says it can go to no more than 100 hrs but if its taken more than 3 years to get to 100 then change it due to seal deteration.

blkdog812 · Post by **blkdog812** » Wed Nov 02, 2011 7:03 am

on older motors: every year
on the newer OPTI motors: up to two years

* if you notice a drop in water pressure, change it *
*if boat sat for a long period of time. change it.*

dont go by hours............

Terry Smith · Post by **Terry Smith** » Wed Nov 02, 2011 9:25 am

jloo283 wrote:
Terry Smith wrote:My 2004 150 optimax has to be done between 75 and 100 hours. Don't know about any other engines
Why kind of issues would you notice if you didn't follow this exact schedule? I've got the same setup, approaching the 80 hr mark. Not that I'm seeing any issue, just would like to get more info from your experience as a precautionary measure. Thanks.

James

James, I start to notice that around 75 hours my water pressure starts droping A little at wide open. As I get more hours on it the water pressure will get down to about 13 lbs at wide open which is still in the safe zone from what the mechanice told me. The only thing I noticed if I wait until 100 hours is that durning the summer when the lake water temps are high if I idle for A long distance after A good run my overheating buzzer will go off. I just bring the idle up A little and it cools the engine it down.

Terry

jloo283 · Post by **jloo283** » Wed Nov 02, 2011 10:11 am

Terry Smith wrote: James, I start to notice that around 75 hours my water pressure starts droping A little at wide open. As I get more hours on it the water pressure will get down to about 13 lbs at wide open which is still in the safe zone from what the mechanice told me. The only thing I noticed if I wait until 100 hours is that durning the summer when the lake water temps are high if I idle for A long distance after A good run my overheating buzzer will go off. I just bring the idle up A little and it cools the engine it down.

Terry

Terry, thanks for you reply. I've been noticing my water psi vary as I mess with the trim, sometimes as low as 7-8psi at wot! Seems to be worst than what you have.

But since i've installed the smart craft monitor, i've been keeping an eye on water temps. They've been in acceptable range and I haven't had any alarms . Plus, I've checked the impeller and it's practically new (or it seems) so I've been putting it off.

Does you impeller look worn at all every time you change it for the psi to drop? Maybe it doesn't matter, I'll change it anyways.

BTW, Terry, the smart craft monitor is a great little unit, check it out if you get a chance.

James

dwise · Post by **dwise** » Wed Nov 02, 2011 11:30 am

I have an 2000 FICHT so I have them change my impeller when I have the yearly maintenance performed. I only use my boat once or twice a month for the club tournaments, so it doesn't get a lot of use.

Terry Smith · Post by **Terry Smith** » Wed Nov 02, 2011 12:04 pm

The impeller doesn't look bad it's usually the gasket on mine that goes bad first. I just change both since I have it apart. 7psi

I think it's time to change!!!!!! 12 psi is what I was told by the mechanic's at Galaxie Marine & C&C Marine. But I'm not A boat engine mechanic so I just have to trust the guys that work on them

TxFishman · Post by **TxFishman** » Thu Nov 03, 2011 3:23 pm

Just got mine change, it had only been a year, but it was a good thing i did, it was started to curl

Cooch · Post by **Cooch** » Fri Nov 04, 2011 7:16 am

This is a very interesting topic, one that you are certainly gonna get a lot of different ideas to. My take is to first start with the Original manufacturer's recommendation, this is the starting point. You should always replace it at their specified time. Yet there are varying conditions for us all, that you should keep in mind, that may key you to have it replace sooner than later. First and foremost is your pressure gage, if you watch it often and it's dropping below regular levels, have it looked at after assuring yer intake is not clogged with debris. Any time ya take it to your mechanic, have him inspect it for you. If you spend a lot of time in saltwater, brackish water or here on the Delta, due to the courser conditions of the water, especially here on the Delta with the constant flow of dirty water, weeds and high sediment content, that impeller can wear and/or corrode faster than normal.

I'm with Poulson, change it regularly, it's not that expensive and will assure proper cooling on a regular basis. I've always had my Johnsons & Evinrudes changed every 6 mos or 100 hrs, which ever came first and never had a failure. My new E-tech is on a 300 hr/3 year schedule, yet I'll have it inspected long before I reach either of those two marks, just to be safe.