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Posts: 44
| My new to me 2001 ESOX Mag with a very strong 2001 60 HP Mercury 2 Stroke will porpoise at the top end. I swapped the Mercury Vengence 11" prop for a PowerTech SRD 13" that they recommended. That prop gave me much better bow lift which I appreciated as I am still getting used to the visual of the squared off bow.
With the PowerTech, I am at 5,100 RPM's and 35 MPH but the boat is porpoising. The motor is mounted right down onto the transom, and when running fast you cannot see the cavitation plate at all which tells me it is too low on the transom? Suggestions do I move one hole up or two?
In checking the people with the Mercury 4S all of them are right down on the transom, but this is probably a different design.
Overall love the boat, and this prop made a huge improvement at what I would consider cruising speeds of 25 MPH to 28 MPH. Planes at 18 to 19 MPH if you need to go that slow.
Edited by GoalieDad30 6/30/2019 9:04 AM
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Posts: 32935
Location: Rhinelander, Wisconsin | Are you trimming the engine at all? If so, reduce that. If not, a 5 degree aluminum wedge between the engine and transom will make a new boat ride out of it, and it's likely your engine bolts should be resealed anyway. TH Marine has them, I think.
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Posts: 44
| Thank you Steve, and I agree after 18 years the bolts should be resealed.
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Posts: 44
| Steve just to confirm, I want the "negative tuck" set correct?
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Posts: 32935
Location: Rhinelander, Wisconsin | Yes sir. You want the engine to be able to trim in more. |
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Posts: 44
| Thank you!
The first time I took the boat out it was a little disconcerting the visual of the bow going 30 MPH. But yesterday after a couple hours of running around on the Sassafras River near my house I am pretty confident in how the boat runs. You just have to learn how to take on the boat wakes but other than that it is amazing how dry it is you would never guess that looking at the hull sitting on the trailer. |
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Posts: 176
| Steve gives good advice on this. I have the Esox LTD hull, (the original narrower ESOX hull).
He gave me the same advice years ago that he gave you, and it's worked great, put in the negative wedge, life the motor up and run it.
Thanks again Steve!
Kevin
Edited by Nomadmusky 6/30/2019 9:59 PM
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Posts: 73
| I've had several people mention to me they've heard that Tuffys are famous for porpoising and ask me if my 1760 does. And the answer is a resounding yes! I love the boat, but it definitely gets pretty hoppy some times. A small design flaw i would guess. |
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Posts: 3508
Location: Elk River, Minnesota | Hiya,
Something else that could potentially be checked is the pin location for the trim when trimmed all the way in. If that is out one or two holes, you can move that pin to tuck the motor under a little more as well.
I tried searching for the specs on that engine and was unsuccessful in finding anything, but I am suspecting it should be reaching 5500 rpms at full throttle. My gut says the rpms are a touch low with the 13 pitch. I'm wondering what rpms did you have with the vengeance? I can potentially see why the vengeance propeller maybe didn't do so well also as it is more or less a stainless design of the stock aluminum, so it does not have much for bow lifting capabilities, hence the lack of the prop to hold the bow up while trimmed.
Steve Worrall has much more experience with that hull, and am guessing he has seen his fare share of how that boat can be properly set up. Depending on how the hull is built, if it does not have much angle back under to the bottom of the transom, I could easily see how the wedges could help tremendously as well.
Steve |
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Posts: 44
| With the Vengeance it would spin up to 6,500 and obviously I still have that prop for those few times when I know I will have three people and full live wells.
Having the wedges installed next week, along with having the motor moved up just one mounting hole at the dealer. They will also reseal the mounting bolts. If I am still too low I can jack it up one more hole myself but to completely remove it isn't something I can handle.
I was at 5,100 with throttle to go so still optimistic that 5,500 is possible.
Could not see the top of the cavitation plate at all when running, so fairly confident that is the primary culprit. Will keep everyone posted on the outcome. |
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