globe impeller for oberdorfer

Ron Hill · April 25, 2010, 03:14:15 PM

Guys : There are two items in an Oberdoffer raw water pump that tend to get forgotten.
1. Face plate - if it has wear or scars you'll need to get a new faceplate or have the old one "refaced" (smoothed out)
2. Escrentic (sp?) insert - this is the brass piece that's screwed into the inside of the pump body to make the inside "unround". I've seen this piece replaced and it's like getting a new pump!

Both of these items "if fixed" will make the pump much more efficient. A few thoughts

David Comando · June 01, 2010, 05:09:12 AM

I recently replaced my 3 season old working impeller. I usually go two years but I "pushed" it for another year. I replaced it with what I thought was a new impeller. When it failed to pump raw water I realized I may have replaced it with an old extra, previously used 2 season one I saved for breakdowns. I immediately replaced it with a new out of the box Globe impeller. It worked immediately...for about an hour of total engine time. When I investigated what was going on I found plastic shavings in the water pump housing. The shaft had stripped the plastic so the shaft was spinning, but the impeller was not. So I am going back to my marine dealer with the stripped Globe impeller, and the extra I purchased. If I can get a Globe with a metal interior I'll get it. Otherwise its back to the original equipment that has worked since 1987. Note that the shaft that's on my water pump is not the "star" type, it's the circular with a flat spot. Perhaps this makes a difference...

Ron Hill · June 13, 2010, 05:17:45 PM

David : You have the standard Oberdoffer impeller shaft with only a flat spot for the impeller to engage.

I'm surprised that you have a Globe impeller with a "plastic insert" for the drive shaft. All of the Globe impellers that I've seen have a bronze insert for the shaft.
You might want to give Globe customer service a call at (781)681-6800. You may have gotten a look a like. A thought

mainesail · June 13, 2010, 07:25:19 PM

Quote from: Ron Hill on June 13, 2010, 05:17:45 PM
David : You have the standard Oberdoffer impeller shaft with only a flat spot for the impeller to engage.

I'm surprised that you have a Globe impeller with a "plastic insert" for the drive shaft. All of the Globe impellers that I've seen have a bronze insert for the shaft.
You might want to give Globe customer service a call at (781)681-6800. You may have gotten a look a like. A thought

Globe uses both materials for hubs. Just look at post #4... Wile I have never seen the hub shed plastic I have spun the hub inside the blue part but not spun it on the shaft.

Stu Jackson · June 13, 2010, 09:10:40 PM

Basically, what I'm hearing is that the Globe impellers are simply not worth it.

My OEM Universal black ones always work for me. Oberdorfer M202-15. (?)

Is that correct?

David Comando · June 14, 2010, 07:12:13 AM

I did go back to a new original impeller. After a few attempts with a soaped-up (as recommended by the dealer) impeller I realized I needed to get it primed to work. Following the information available on this site I got it primed and working. I returned the Globe back-up I purchased and have a new OEM Universal instead. This is an area I feel I'm better off going with what has worked since 1987. I'll continue changing it every 2 years for peace of mind. Now back to checking if the fridge is working with a cold beer!

Ron Hill · June 14, 2010, 06:22:25 PM

Guess I've had better luck than Mainsail.
When I run into a problem I pick up the telephone (NOT an Email!!) and call that companies Customer Service. I tell them that I've had a problem with their product and describe it in detail. They usually send me a new replacement item.

Guess in my limited 20 years with using and recommending Globe, I've never seen the plastic center insert.

I'll guarantee, that if I only got 35 hrs out a Globe impeller they would have damn sure heard about it !!!!

David Comando · June 17, 2010, 06:01:34 AM

I'd rather be moving onto another issue but I still have not solved my raw water pump issue. Everytime I think I have it solved, I go out sailing, and when I start the engine to get back to the dock, it doesn't pump. The Globe impeller with the plastic insert came out of a Globe box, it was part # 815. I have a call into Globe customer service. Two nights ago I went out sailing with the pump working, only to return to the dock by sail. I removed my speed seal, wet sanded the mounting surfaces, cleaned out the o-ring groove, siliconed it, replaced it, and finger tightened the speed seal. Last night it worked again only to have me sail to the dock again as it wouldn't pump after a 2 hour sail. Today I'm going back to the original cover after I wet sand it. Any other suggesstions will be appreciated. Is it time for a new pump???

Gary · June 17, 2010, 08:18:54 AM

I found the Globe Impeller was not reliable at keeping raw water flow. I would report the same issues that you have experienced with unreliable water flow. I did two things that have solved the problem. One is to make sure that the seacock and strainer connections before the impeller are tight and in one case at the strainer added teflon tape for a tighter fit. I think there may have been a slight air leak impeding the vacuum there. The second was to return to the original rubber impeller.

I have had no problems since doing these two things. Also, you might check your seacock for an obstruction by using the dinghy pump or a wooden dowel to clear. You should have a good three to five inch head pressure when the hose is removed from the raw water seacock.

Gary

SeaFever · June 17, 2010, 08:39:36 AM

David,

Somehow it sounds like we have not solved your root cause. Please post what you find today. It is very interesting that you have problems after few hours of sail. Just out of curiosity, have you tried turning on the engine at intervals while you are sailing just to check if things work properly? Just a thought.

Ken Juul · June 17, 2010, 08:58:10 AM

So the pump works when the engine is cold, but looses prime after shutdown. Have you put a straight edge on the speedseal? Maybe it has a slight warp in it that increases with heat. Even if it measures flat, might want to put the original cover back on to see if there is any difference.

David Comando · June 17, 2010, 09:29:14 AM

While I was first analyzing the problem, I did loosen up the intake hose. I don't remember if I tightened it. That will be the first thing I check when I get aboard KS this afternoon. I'm actually hoping that it's loose!Thanks for all the advise. I'll be working on it till I get it right. I'll keep you updated.

Ron Hill · June 17, 2010, 03:38:59 PM

David : Sorry to hear that nothing seems to work. You are somehow loosing your prime, because air is getting into the system !
Here's a temporary fix that may help, but will be a pain in the butt :
When you get out to the sailing area and you shut down the engine close the thru hull for the raw water. Start the engine after you are done sailing and open the thru hull.

Has someone rerouted your raw water hose? The factory had it coming from the thru hull, up over the top of the engine, and then down to the Oberdoffer.
Air can only get into the intake of that system in a couple of places : the face plate gasket, the intake hose clamp to the pump, the lip seal keeping the water in the pump, a rubbed hole in the hose? and that hose on to the thru hull.

I can tell you that the raw water hose is 5/8" ID and the thru hull hose fitting is 1/2" OD !!! So that hose MUST be clamped and most of us double clamp all thru hull hoses.

As I previously mentioned don't forget that es-centric piece on the inside of the pump.
A few thoughts that I hope help.

SeaFever · June 17, 2010, 10:36:20 PM

David,

By any chance do you have a water strainer between the thru hull and the water pump? If so, that could be another item that could be leaking air in resulting in your loss of 'prime'. Just a thought that came to mind when I was trying to picture your situation.

David Comando · June 18, 2010, 05:18:32 AM

To all,

Thanks for your help. With your suggestions I found the problem. Just past the strainer are the nylon fittings that attach to the intake hose to the water pump. Water was slowly weeping. I put teflon tape on all the fittings and on the bowl to the strainer and tightened down. Then after I bled the intake hose and reattached it to the water pump I realized that the hose clamp that I tightened numerous times wasn't really tightening (stripped). I replaced it with a new clamp. I started the engine and immediately water pumped. I feel confident that after a sail this weekend, the system will maintain a vaccume and all will be well. Happy Father's Day, I know where I'll be and I'm sure it won't be working on the water pump!