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Hi All,
1976 Pearson 30 with original (I assume) A4.
I'm about to embark on impeller/pump maintenence. Reading the MMI Service & Overhaul Manual, this looks like quite the project. It looks like it can only feasibly be done with the pump off the engine.
Impeller plus MMI back plate kit (assuming the pump is not an "N" model) would be $75. I'm thinking that, for an additional $150, I could upgrade the pump to the MMI 502, which looks to be much less a maintenence ordeal? Would it make sense to do that? The differential becomes even less if I add new bearings, gasket, etc. to the existing pump.
It looks like impeller replacement on the MMI 502 eliminates the need for dealing with a snap-ring?
What about major maintenence on the MMI 502: How does it hold up, compared to the Oberdorfer? Less-frequent major maintence, or more-frequent?
New questions...
The product info for the MMI 502 says "The inlet and outlet on this pump are 3/8" pipe thread, and it is otherwise interchangeable..." Then I notice, on the Brass Fittings page: Product No. - BRSS_05_427 - Brass hs brb 3/8" MNPT x 1/2" barb "long stem" 90. Is this one of the two fittings I need for this pump?
I'm guessing the existing pump's fittings are 1/2" NPT? In looking at our boat's raw water fittings at the through-hull, it looks like the fitting there is 1/2" NPT. I noticed, in creating an "extension hose" last fall, for sucking RV anti-freeze out of a bucket, that a 3/4" male/male adaptor fits in my existing coolant hose. So I suspect the existing hose is over-sized. If so, it looks like I'll need to replace the hose for the smaller 3/8" NPT fittings on the new pump?
(Kind of wondering why the MMI 502 has 3/8" NPT fittings when the original apparently had 1/2" NPT fittings...)
Will I be able to get a socket wrench with an extension on it under the old/new pump to get to the bottom flange bolt?
A lot of questions, I know, but the boat is an hour away, so I like to have my ducks all in a row, having all tools and materials I'll need, knowing exactly what I'm facing, whenever I go over there to do a project
.
Thanks,
Jim
1976 Pearson 30 with original (I assume) A4.
I'm about to embark on impeller/pump maintenence. Reading the MMI Service & Overhaul Manual, this looks like quite the project. It looks like it can only feasibly be done with the pump off the engine.
Impeller plus MMI back plate kit (assuming the pump is not an "N" model) would be $75. I'm thinking that, for an additional $150, I could upgrade the pump to the MMI 502, which looks to be much less a maintenence ordeal? Would it make sense to do that? The differential becomes even less if I add new bearings, gasket, etc. to the existing pump.
It looks like impeller replacement on the MMI 502 eliminates the need for dealing with a snap-ring?
What about major maintenence on the MMI 502: How does it hold up, compared to the Oberdorfer? Less-frequent major maintence, or more-frequent?
New questions...
The product info for the MMI 502 says "The inlet and outlet on this pump are 3/8" pipe thread, and it is otherwise interchangeable..." Then I notice, on the Brass Fittings page: Product No. - BRSS_05_427 - Brass hs brb 3/8" MNPT x 1/2" barb "long stem" 90. Is this one of the two fittings I need for this pump?
I'm guessing the existing pump's fittings are 1/2" NPT? In looking at our boat's raw water fittings at the through-hull, it looks like the fitting there is 1/2" NPT. I noticed, in creating an "extension hose" last fall, for sucking RV anti-freeze out of a bucket, that a 3/4" male/male adaptor fits in my existing coolant hose. So I suspect the existing hose is over-sized. If so, it looks like I'll need to replace the hose for the smaller 3/8" NPT fittings on the new pump?
(Kind of wondering why the MMI 502 has 3/8" NPT fittings when the original apparently had 1/2" NPT fittings...)
Will I be able to get a socket wrench with an extension on it under the old/new pump to get to the bottom flange bolt?
A lot of questions, I know, but the boat is an hour away, so I like to have my ducks all in a row, having all tools and materials I'll need, knowing exactly what I'm facing, whenever I go over there to do a project
.Thanks,
Jim
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