Chopper

[littleredridinghood]

I need some advice wich pitch to run a 28P or a 30P chopper I have a 2.5 stock carburated 200 merc and it's sitting on a 1991 2.0 135 lower unit with speed cone wich I believe the gear ratio it's a 2.1 please correct me if I'm wrong. what kind of RPM would I run with this match and what would be the ideal pitch for top speed also keeping in mind that is going on a Hydrostream Vector.

[fastercat]

start with 28 pitch and go from there 6500rpm max good luck i think you may want to go down in pitch.gears are prob 187to1 :confused:

[littleredridinghood]

might anyone know what gear ratio the lower unit I'm running might be?

[pyro]

It's a 2:1

You need a 1.87:1 for that combo. You'll run out of RPM no matter how big of prop you run.

Keep in mind, the 28p and 30p "big-ear choppers" are much different props. The 30p has smaller diameter, and narrow, high-rake blades like the small-ear models. The 28p and lower have wider ears, and 14.5" diameter.

A 200 on a Vector should push it to 80-85 mph with ease, possibly faster with the right setup. The gear change would amount to be a 5 mph difference, assuming you could spin 6500 rpm with a 30p wheel with either gearset.

Use this: http://www.rbbi.com/folders/prop/propcalc.htm

[littleredridinghood]

a buddy has a 28P chopper could I take it to a prop shop and pitch it to a 30P would that be any good and safe

[pyro]

Often, the pitching-up comes in the form of cupping and other techniques that may somewhat alter the performance of the prop. Chances are, there might be another model of 30p prop that would run better, possibly an ET, Mazco RE, Spinelli, etc. Try some others before hacking up the only good one you've got.

It the 28p a big-ear?

[vector mike]

I had a 200 on my Vector before the Bridgeport with a 2:1 gearcase and never ran anything smaller than a 29. I have tried a 26ET copy, 28 big ear chopper(for sale or trade), 29 OMC Cleaver and a Spinelli 32 Cleaver. I found that the Cleavers ran the best with my setup because the last thing you need on a Vector is bowlift. The Cleavers give enough bowlift and still lift the stern to get it flying. I run the 32 Spinelli cleaver on it now with the Bridgeport.

[littleredridinghood]

so is a cleaver better? and would I be able to turn a 32P and what kind of RPMs

[vector mike]

On my setup they work the best for me but everyones boat is different.