Lower Unit gear ratio

[CNT]

I'm running a 1988 2.4 200 hp. Merc. with the stock lower unit. Can anyone tell me what the gear ratio is on this unit? I'm turning a 23p, four- bladed prop. at 6100 rpms. and getting about 66 mph. Any suggestions on how to get more speed? I'm getting 135 psi. and I'm getting the heads milled to 145-150 psi. What gear ratio would be best for a bass boat, and any suggestions on what prop to turn? I don't really want to turn anymore RPM.'s than possible but want to run between 70-75 mph.

[WATERWINGS]

It should be 1.87:1, unless it has a case off of an older 150, then it would be 2 to 1, but with the numbers you quoted, it sounds like 1.87:1

[Raceman]

You really didn't give us quite enough information for the bass boaters among us to give you real solid advice. You'll need to at least post the kind of boat and how much setback, if any. Some boats respond better to setback than others and of course load is a big factor also. Your best bang for the buck is obviously setup and propeller.

What are your plans for fuel when you cut the heads? Sounds like you're flirtin' with the danger zone for pump gas.

[CNT]

I'm trying to stay with pump fuel so I'll probably just get the heads cut to 145psi. . I'm running a 18' Javelin Bass boat ( not the fastest hull I know), and I have a twelve inch set back mercury jack plate on it. I installed a nose cone on it last year and picked up some speed along with RPM's. I also milled the heads to give me 135 psi. and noticed a little difference, but noticed even more of a difference when I installed cabon fiber reeds and velocity stacks. I'm still looking to get a little more out of her without doing any major mods. to the motor and without loosing to much lower end. I'm probably asking for the impossible but I still need to get the boat loaded with fishing gear out of the whole. I'm getting out of the whole just fine and turning 6200 rpm's on top end. I think I just need to borrow a few different props and head to the lake with some water shoes and a floating wrench!!!!
What do you think?

[vector mike]

Are you running a through hub or over hub prop? The over hub usually gives you a little more slip to get the revs up at the start and gives a good top end too. Don't forget the extra prop nut!