can i run a high volume fuel pump with combo. if so what pump do you suggest. motor is 540 with holley hp 950

use a electric fuel pump with the oil presure switch to meet coastgaurd requierments

I used a Carter HV pump on my 540. The bottom of the Carter bolts right to the top half of the stock merc pump.

KCHOBOAT,
Which Carter pump did you get? I presume you bought the Carter HV pump, then only used the bottom half of it and bolted it to the top half of the merc belt driven pump?

I see that CP Performance sells a bottom half kit for the merc pump, but in my opinion overpriced at $150. I would guess that the entire Carter HV pump you are talking about was under $100??

That is what I did the second time. The first time I bought mine from CP and paided to much. Buy it at an automotive parts store. It is the same thing Cp sells for less and just switch out the top halfs.

Thanks for the tip.
Is there a particular Carter HV pump # that you recommend? What is the estimated gph of the new combination pump?
Also, I know that a conventional mechanical pump won't work on the merc belt-driven setup, but never knew what the difference was. Is the pump arm different or what?

Rich

The pump arm is different. Holley also makes a marine mech pump that will bolt up to the merc arm. I use them with my twin-750s and they hold pressure fine..

I just ask for a big block pump. Beside the arm the other reason for using the the merc top is for the hose that runs to the flame arrestor. The pump flows about 120 GPH at 6-8 psi.

Here's another thread with some good info.

http://www.offshoreonly.com/forums/s...threadid=52632

Thank you all for the good info.

Rich