Impeller hrs

[sailrmon]

Does anyone have a recommended service schedule for raw water impellers. I know a lot depends on the water you are in salt/fresh debris or mostly clean. the last time i changed mine i had 262 hrs on it and it looked like new. vanes were very flexible with no signs of any cracking or stiffness.
I am thinking of extending my service to 400 hrs, any thoughts on this would be appreciated.

Thanks

Bill

[sailingdog]

Generally, changing them once a year is a good idea. They're not all that expensive.

[sailrmon]

I seem to have the most expensive one out there at $73.00 dollars, Yanmar 4jh2e. I know, i sound like a tight %&^#.

Bill

[trantor12020]

My Johnson 810 impeller on my Yanmar 2GM20F lasted 5 years. I checked the manual and it failed at about the recommended running hours.

[sailingdog]

The only reason I say that you should probably change the impeller out every year is that if the impeller is run dry at all, it will generally "age" much more quickly and become brittle with the heat caused by running dry. This tends to leave it more vulnerable to breaking off vanes and can cause you serious problems by blocking the cooling system. Also, many impellers will take a set when sitting in the same position for extended periods of time... which also makes them more prone to losing vanes.

BTW, if you've had to run the engine dry for any reason, it is probably a good idea to change the impeller as soon as possible for the reason I mentioned above.

If you're careful about removing them, you can always set the old impeller aside for use as an emergency spare.

[BarryL]

Hello,

I don't know what the service recommendation is. I check mine when the boat is hauled. The one in the pic was in the boat when I bought it. So it's been in the pump since at least 2006 and 150 hours. Considering how the PO treated the boat, I would think the impeller is much older.



Anyway, after running marine antifreeze through the raw water, I pulled the cover off the impeller and took a good look. I could see that the rubber was starting to crack. I pulled the impeller and I'll install a new one in the spring.



Barry

[Bene505]

I just replace mine. I ran the engine for a few minutes with the seac0ck closed. It was a great excuse to have a mechanic look over the whole engine, and to give me a diesel engine lesson. The impeller looked like new. I replaced it anyway and kept the old one for a spare. Note that you need to get a spare gasket (mine are paper and are destroyed at time of removal) or you won't be able to use that old, usable impeller.

It was also a good time to swap out the antifreeze, which turnd out to be a bit watery. This may be the boat's first winter north of Georgia. Also it had "green" antifreeze, but Perkins engines like "blue" apparently.

[SVCetacea]

Originally Posted by sailrmon

I seem to have the most expensive one out there at $73.00 dollars, Yanmar 4jh2e. I know, i sound like a tight %&^#.

Bill

Try the Globe #075. Defender has them for $34.

[Cruisingdad]

100 hours or 12 months, whichever comes first. Running it past the 12 month timeframe is risky. It will fail when you need it most. THey are not expensive and it is easy to do. Just make it part of your oil change maintenance. No big deal.

- CD

[timebandit]

I change mine once a year.

I hate supprises, they come at the worst time.

I say when I change the damn thing not the engine.

I throw the old one away and buy a new spare and gaskets just incase.

I have an outboard and cannot even imagine hauling it aboard and pulling the lower end to change it.

Right after the new year it comes apart and gets s full tune up regard less of run time. It always starts on the second pull when cold and the first when warm.

I do a couple of dozen engines in January from my little one to up to the new v-6s for my motorcycle clients.