Impellor life

"I've got the sherwood E35

"I've got the sherwood E35 and been seeing quite a bit of torn blades, even a missing blade at 150 hours/2 years. Is this about typical? I know they recommend annual replacment, and would like to hear your experiences."

"Not typical--I know a guy who

"Not typical--I know a guy who got 22 years out a set of impellers! (An extreme example, I know.)

I suspect you have some type of problem with the pump body, a bad "new" impeller (dried out in storage), or a bunch of nasty, abrasive stuff coming through your strainer.

You DO have an inlet strainer?

Jeff"

"dave:

when fishing in the

"dave:

when fishing in the ocean, we could go 2 years (~600 hrs) on a good set. Switched over to the jabsco replacements as, in my opinion, they are of much better design. we have gone as long a 5 years with them but usually change between at 3 years.

believe it or not, they seem to last longer with use, and this holds for all brands. as long as you keep them moving (w/ water flowing of course) and keep thte grit out, they last much longer. I think the compression on the blades in an idle pump kills most of them.

I have the original Sherwoods, w/o fittings. If you desire them as spares, send me an email.

mark"

"I've got good Groco strai

"I've got good Groco strainers, and this 1 to 2 year life is happening on both engines, so, I'm kind of stumped. I notice that the cam is rather sharp on the leading edge, and may be taking out the vanes. I'll do a major rebuild on the next cycle."

"i think you can flip the cams

"i think you can flip the cams on the sherwoods. the jabsco cam has a pin to anchor the wearplate.

the leading edge should be dull vs sharp. If you look closely, I'll be the 'fingers' of the cam have worn 'thinner' on the output side, too. Not only does it attach the impeller blades but it also reduces the volume delivered."

"Although subjective, the impe

"Although subjective, the impeller replacement sheet describes usage between 6 months and 2 years as normal. But then sometimes while backing into our slip, the mud and grit that gets stirred up is strong as well as a set of keys I had dropped overboard once and several other forms of detritis. Add this to the possibility of the rough edged cam and this may be the problem. My E35 impellers get changed about every other season so far."

"I am convinced that air leaki

"I am convinced that air leaking in the intake to the pump can cause short life of the impeller. I was changing impellers on the water pump of my generator every 25 hours. I found a crack in the raw water strainer. After replacement of the raw water strainer, I have not had to replace any impellers after 200 hours.

I agree with makomark that sitting for long peroids can destroy their capacity to move water. I believe this is caused by several of the flukes getting distorted permanently while setting.

Chuck Hanson"

"chuck:

you are right about

"chuck:

you are right about the air in the pump, just like running an engine without enough oil. Ask the outboard guys how long their impellers last when they flush out their engines without turning the hose on first!

it doesn't help the cooling function either; aerated water has a big reduction in its heat transfer function."

"Being a vessel examiner (

"Being a vessel examiner (CG Auxiliary), I watch hundreds of boat launchings at a local lake. You wouldn't believe how many boaters dry start their engines--"To make sure it'll start on the ramp." Yikes! Especially the Jet Skiers. Some guys rev the snort out of them as well. Yet...

Then again, I see some people launch then retrieve their boats a short time later. Maybe they were overheating?

Jeff"