Sherwood vs Seamax?

A recent question:

I am just learning about these pumps and at 1000 hrs on 330B, my starboard raw water pump began leaking at a rate to great to ignore. So after plunking down over $1600 with California’s 8.75% sales tax for two, if one’s bad the other must be near death right? However after reading your article (Changing the Raw Water Pump), maybe not. I thought I’d read up on replacement. Would you return these and get the Seamax pumps? Do you know if anybody has any real time using the Seamax 1730X? What do think? 1000hrs isn’t horrible mostly in salt water.  My big-block in the last boat needed valves at 1600hrs. I agree that Cummins makes a great engine. In case tractors the Cummins engine is good for at least 8000hrs.



My response:

I had spare Sherwood pumps kicking around when the Seamax was first released.  I considered returning or selling the spare Sherwoods, but decided it wasn’t worth the hassle. When I do install them, I’ll replace them with Seamax. I’ve just heard too many good things about them.

I’m actually getting respectable pump life out of the Sherwoods these days. I still favor Seamax based upon what I’ve been hearing, but my Sherwoods have been doing fine lately.

The only reason I would return your pumps is the price. $1600 is way high. You can get them, or the Seamax pump, for much less.  Personally, I would lean towards returning them.




James Hamilton



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4 comments on “Sherwood vs Seamax?
  1. Fred says:

    Having just experienced what sounds like the same failure, I’m very worried about the pump on the other engine

    • Gear train damage is serious and can be expensive so, if you have reason to believe that the damage to you engine was related to the use of aSeamax pump, I personally would be highly motivated to the change the pump on the other engine even if I had to eat the cost of replacment.

  2. Tim Conners says:

    Warning! Do not use the Seamax pumps! I learned the hard way. My sherwood pump on my cummins 6bta was going thru impellers. I replaced it with an expensive Seamax pump. After around 1000 hours the teeth on the drive gear sheared off. This damaged the gear on my cam so now I’ll need to pretty much rebuild the motor. I purchased the seamax pump from Tony Athens at Seaboard marine. It was only 15 months old and the warranty is advertised as a “no hassle 2 year warranty”. When I contacted Tony at Seaboard marine, he will not take responsibility for the pump or damage to the motor. He is coming up with all kinds of lame excuses trying to blame the installation or the cam gear. Since this happened, I have spoken with mechanics who have seen this before. It’s not worth risking your engine. It’s much better to just change impellers more often and even change out the sherwood pump occasionally

    • James Hamilton says:

      Tim Conners story of timing gear damage afer installing SeaMax pump is a tough one. There are many possible causes of gear train damage not all related to pump design or manufacturing issuses. I’ve not heard of other any other faults potentially related to these pumps but, since I’ve since switched to John Deere power I’m not watching as closely as I used to. Timng gear damage is not not a common failure mode and it certainly is an expensive one so this one story is a concerning one. Sorry to hear about this one Tim.

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