anything special to put on a chopper prop?

[Bull_in_a_china_shop]

I'm going to go straight down to the marina and put in on my 75 merc I6. Will I need any special hardware?

[Cp]

....you'll need a thrust washer, a tab washer, a prop nut, and the appropriate socket/ratchet.

Cp

[Bull_in_a_china_shop]

good, i believe they're 1 1/16 nut but i'm all set then

[crazy horse]

You will need to get rid of your trim tab if it's still on your case.

[pyro]

You need to JACK THAT MOTOR UP or the prop is going to suck.
It needs to run half-submerged to work properly and offer any performance gain.

[tombrown]

Biacs, I think you'll like that prop and it will perform well on your boat. Unfortunately, a 22p chopper is a wee bit much given that you're running the gear case burried. It would help if you raise the engine as far as you can by going to the highest holes on the transom clamp.

The only real problem you're likely to have is the classic steering problems of the boat pulling really hard to the left. The chopper should be a little better than the aluminum prop, though. I found it got a little better with the engine higher too but I never surfaced a prop with my CVX/1500/24p chopper. Like you, I ran the gear case burried pretty deep. The chopper still provided a solid performance gain.

You'll have a bunch of chine walk too. My boat had less chine walk at 55 with the chopper than it did at 50 with my 3 blade aluminum. Still, it wasn't as good as it could be so I put a dual cable steering system on it. That helped a lot and made it quite drivable.

Good luck. I'm looking forward to hearing your results.

By the way, the 24p chopper was too much prop for my 1500 with the gear case burried and the engine developed a hole in piston number 3. I was only turning about 5000 RPM at WOT. You really should consider getting the engine higher to get your RPM up. Don't be affraid of a jack plate. You don't need to mangle your boat to do it.

Most jack plates aren't the greatest fit on the L6 Mercs so do a search on it. There is a ton of information on the subject in the general and technical forum here. There is also a ton of information on putting a hole in the 3rd cylinder with too much load. These guys know what they're talking about when they say to prop it for 5800-6000 RPM WOT.


Good luck,

Tom

[Raceman]

I don't agree either that the Chopper won't help unless the engine's raised. When they first came out a lot of folks ran em buried. The Chopper was introduced long before the jackplate and low water pickup nosecones. Remember, it's 70's technology. Everybody ran low compared to what we do today. I ran one on an 18' SuperSidewinder with no setback and no notch in the bottom........basically a 20" motor on a 20" transom and it was far superior to the 3 blade Merc stainless blade that I ran also. Like somebody else pointed out, if you don't get that engine in the upper 5's MINIMUM at wide open throttle, it'll burn a piston.

[Bull_in_a_china_shop]

i got a delivery card today, so I should be able to run it in the next couple of days. As for the motor. I should tilt it up higher on the bracket on the stern??

[kevlar3000]

Hey Bull,

Give her a good run, if it doesn't work out I stand by my promise to send your check back. My CV V6 150 is buried as well but the performance gain as well as overall handleing of my boat were dramatically better than the aluminum it came with. Even buried I am turning 5700 (my V6 rated for 5500) rpm with my 24 small ear, I know if I get a jackplate I am going to need more pitch, but in the meantime I am quite happy with the performance of my old 74 CV and stock motor with no mods. As has been said make sure you are getting the rpms that you need. Use your tilt/ trim to lift your height.

Keep me posted....