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Posts: 479
Location: Eden Prairie & Pine Island | I understand if you want a better hole shot you can get a prop with a slightly lower pitch and still not lose much, if any, top end speed. Anyone care to comment or know if this advice is sound? |
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Posts: 24
| Hey,
I know this much from trial and error.
I went up from a 19 to a 21 pitch prop and gained 8 mph top end with minimal lost of hole shot.
At the end of the day I think the gain of top end outweight the Drop in hole shot.
My Two cents |
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Posts: 32954
Location: Rhinelander, Wisconsin | For every 2 digits up (eg, 19 pitch to a 21) you will lose about 250 RPM and may pick up some speed, while adding a second or two to the hole shot. The operating range of your outboard is pretty important, don't want to go over or too far unter the recommended RPM range. I ran about 5700 RPM with a 21 Revolution Four, and about 5450 with a 23 last year with my 250 Opti max XS. The 23 was a bit faster. |
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| To Piggy Back of SWorral's Comments, you can potentially gain some of your RPM's back by raising the motor a bolt hole or possibly two. It's roughly 100rpm for every bolt hole. The idea here is that the less "stuff" that is in the water, the faster you will go. the downfall to this is when you raise the motor, your handling will be less (minimal though with the correct prop)
Testing is the fun part. If you can, raise the motor one hole and take it for a test ride. If the prop does not blow out on a moderate turn, go back and raise one more bolt hole. If it starts to blow out, trim it down just a tad. If it continues, lower the motor back down one hole and you will be as tuned in as best you can with that particular prop without a jack plate.
When the motor and prop are matched well with the boat, it will feel like it's floating along in the water at 4500 or so RPMs....a nice cruise...so to speak.
Steve |
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Posts: 1335
Location: Chicago, Beverly | VMS Steve and Steve Worral, I have a rampage 160xt(Tuffy) with a 40hp evinrude.. Thing blows out every time with a tight turn.. Are Rampages known for this problem? Its an older one, 1983 with the sponsoned vee hull. I currently run a 12 1/4*15 prop cupped by airmarine of Chicago and ocasionally run a 11 3/4*17 when on bigger water where I can get the use of the speed on that prop..as its a tiller I have no tach hooked up and have no idea what its turning.. I am gettinng around 33-35mph out of the 15 with a gps(I think its more like 33) and at least 35 on the 17. Holeshot is especially good on the 15 and not horrible on the 17, just like an extra second or two before it gets on plane compared to the 15.. |
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Posts: 1185
Location: Wishin I Was Fishin' | If your boat is heavy....stepping up to a four blade from a three helps the hole shot. |
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Posts: 2384
Location: On the X that marks the mucky spot | Not always Jo. B&W Boat Mag did a test with a 620 and the stock 3 blade had a better hole shot then the 6 4 blades they tried.
For best performance, your motor should be turning around 3500-4000 RPM's at take-off. The new merc props (Tempest and Trophy) have plugs that you can interchange to get the best hole-shot. Raising your motor will help your topend, but do nothing if not hurt your low-end. When your motor is raised, you have more of a chance of blow-out. A hydrolic jackplate is the way to go if you want to spend the dough. Keep it low at take-off and raise it as you go. If you do decide to raise it, make sure you have a water pressure gauge so you don't starve it for water.
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Location: Minneapolis, MN | 4 blades do a better job of giving lift to a transom heavy boat rather than improving hole shot. Something else to consider is water temp. Some boats will have very different whole shot difference between summer and fall. Changing the PVS vent plugs can help a ton. |
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Hole Shot & Props