Are you talking about your cirulator water pumps? If that is the case then I would say that you probably should leave them on. If you take them off a stock motor then you run the likelyhood of increasing your water preasure by to much.

Jon

No Circulators when I got the boat .....just raw water pump ....why would less pump ( which is what a Circulator does) make more pressue ? I have been reading about Circulator issues but thought if you run circulators increases Pressure .....

I took mine off last year, and while I am re-rigging the boat, I am installing the Merc pressure relief valves to avoid any water pressure issues.

Do a search in both the tech Q&A forum, and the general boating discussion on "water pressure" , and you will find plenty of information on this topic.

My 2 cents is that crossovers are fine if you use a pressure relief valve in the raw water line before the crossover. The Merc relief valves list for around $125, and you will need to have thru hull fittings somewhere to dump the extra water out. The reason I put crossovers on is that my circ pumps failed, and I run blowers, so I went for the crossovers for extra cooling. It also makes the front of engine easier to work on and look better.

For some reason the stock circ pump doesn't allow the block to become overpressured, probably because it doesn't allow too much flow in. With crossovers, whatever the sea pump is throwing at the block gets to the block, some boaters who run water psi gauges have seen over 60 psi! That's enough to blow gaskets. Some of my friends would blow hoses right off due to overpressure conditions. I never tested my water psi, but I am not going to risk it.

I will deff look up the info available ....I do remember something about restrictors ....I guess not to allow so much water ? But seems the pressure would be as high if not higher ...or maybe I am thinking about the pressure relief valves ...

Hmmmmmm, maybe I'm a "circulating pump bumpkin", but I've never heard of anyone removing the circulating pump. Why would this be advantageous?

Seems to me if you could or should run without a circulating pump, the engine manufacturers would omit them and save money for themselves.

The motors come from GM with the pumps on them.

The circ pumps ensure even block temps versus no circ pumps, especially in colder waters.

They also act as restrictions to extreme water pressure situations.

And you CANT run crossovers without additional plumbing for pressure dumps which negates the price advantage for Merc.

Advantage to not running them? Frees up 5 or 6 horsepower. Looks cool.

well ...6hp and looking cool might cost me 10K >>

Thanks for the expalination

For 5-6 hp and a little better looks, I'll leave my pumps in place.

Gee, I guess gaining five or six hp would probably increase my top speed by about .09 mph. To me the "hassle factor" intself wouldn't be worth it. Besides, for those with cool looking anodized or powerder coatd pulleys, it give one less cool thing to look at.

Personally I'm waiting for "lighted" or "strobing" fan belts.