This question is to help Me , Bill272 and any other twin BB small (27') boats owners who hate getting to Merc seawater pumps.
Do any of you have a RWC set up using a Jabsco or Johnson crank driven seawater pump and a Merc circulating pump.
This sure would make life a lot easier when it come time to change impellers It could be done , kneeling on the back seat in 10 to 15 minutes. My best time with the Merc pump is 1 hour per side
C Spray , I know you use this but you have a closed system. It really shouldn't make that much difference one way or the other but I would just like to be sure. Reason being, the Jabsco pump is 13gpm at 2000 rpm and the Merc. is 22gpm @ 2000.
Would Merc over engineer something like this or do they really feel it's a necessity

24hrs and nobody's got this setup

I have run a jabsco on a blown motor but I also had dry or water injected headers. I personally think that Merc pumps excess water. Possibly to cool the exhaust. It is definently not required for the motor cooling in my opinion. Depending on water pickup once you are up to speed you can force feed enough water or too much if you are not careful. I have seen the set up you are talking about on other boats but no one that I know runs them. I have seen pictures also but I have CRS so I don't remember where right now. There is a pic of apache77's 632 motor that has the type or model pump you are talking about but he also has closed cooling. Not much help sorry.

What's the part number of the Jabsco pump and where is it mounted. The stock pump on my starboard motor can't be accessed because of the Whipplecharger. I'm intrested in switching to something easier to get to.

DaveHam

DaveHam,
Try www.jabsco.com/cooling.asp

I think I'm going to go with the 23800-0201's for mine

I run the Jabsco/Johnson type of pump. Works fine.

I run the jabsco on my small blocks....but I got the BB pump. Impeller swaps can be done in less than 5 minutes, and it cost me less than 1/2 the proce of mercs. I run the pumps at 6000 rpms, and have no issues.

Simple installation, all you had to do was plumb the water to it ?

Check this site out. I can't remember where I ordered them from, but at 139 + the torques bracket (15 bucks) each, they were a lot less than the mercs.

http://marineengineparts.com/shopsit...ml/page84.html

Rachet, do you have a source or link for the bracket??

I just asked the guys where I bought it........they knew what I needed (I paid $15 for each bracket).

Click on the link I gave you, call them up and ask them. They knew exactly what it was.

You could actually make one. Take a look at P/N JP10-24232-1

The bracket goes around the stud on the bottom of the pump in the pic & bolts to the front of the block (mine was a little sloppy, so I made a bushing out of a hose). Anyways, all you need to do is make a bracket that goes from this to the block. Since my boat's covered for the winter :-( I can't send a pic, but as soon as you mount it (which you can rotate it in any direction that's convenient to your plumbing), to the crank, you'll know what I mean.

By the way though, don't buy the bolt kit....................Its like $12 for a couple of bolts & washers.....buy what you need locally.

Ratchet

Oh yeah, like I said, the whole set up (for twins) cost me $325 plus the hoses from the back of the boat. Not bad, and less than 1/2 the proce of the mercs.


Check out this link...........it gives you a pic of where the pumps are: http://www.johnson-pump.com/JPMarine/default.htm

Click on "products by pump type"
Click on "raw water pumps"

Oh yeah , P/N JP10-24232-1 is the pump I am using, not the bracket. My apologies