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Posts: 1209
Location: E. Tenn | This came up in a conversation earlier today.. I have a tiller version with a 60 Merc.
What sort of top end speed are you guys getting?
Also mine starts porpoising @ 27 m.p.h., any suggestions as to how to overcome this would be appreciated. |
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Posts: 32801
Location: Rhinelander, Wisconsin | 5 degree engine mounting wedges. Don't trim out past the point where it stats to wiggle a bit. Stainless prop. What year Mag, front or rear trolling motor batteries?
https://www.ebay.com/p/1611840737?iid=291557951034&chn=ps&norover=1&... |
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Posts: 1209
Location: E. Tenn | It's a 2018, one of the last from Fiberdome I'd imagine. 2 Group 30 batteries, 3 bank charger, and a Terrova all in front. If it makes a difference the O/B is a CT, geared 2.33:1.
Thanks! |
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Posts: 32801
Location: Rhinelander, Wisconsin | 5 degree wedges and a stainless prop will help a lot. |
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Posts: 176
| Although I don't have the Esox Magnum I have the Esox LTD, (the slimmed down, fit and trim one, not as wide in the waste). Steve gave me the same advice many years ago and it made a huge difference. Once I put on the 5 degree wedge it made all the difference in the world. I had a 3 blade stainless on before and with my new motor I have a 4 blade stainless and now it "sticks" to the water and the handling is even better than it was before which was very good.
Kevin |
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Posts: 13
Location: Illinois | Used to have an 01 Esox Magnum with a 60hp Mercury 4 stroke tiller. It topped out at 36 mph with an old, beat up Aluminum prop. Always hit at least 32-34 mph with a big load. Could only hit 36 mph if I tilted the motor up a little bit. Very smooth ride.
Anyone able to share their top end speed with a stainless prop?
Thank you.
Edited by Brandyn Shepherd 3/30/2020 11:21 PM
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Posts: 1209
Location: E. Tenn | sworrall - 3/23/2020 10:57 AM
5 degree wedges and a stainless prop will help a lot.
Thanks much for the advice, wedges are ordered... one more question..
Current aluminum prop is 14X11 3 blade, and runs 6000 rpm/ 29 mph. WOT. stay with the same pitch or change?
Again thanks for the help!
Edited by miket55 4/5/2020 9:56 AM
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Posts: 349
| sworrall - 3/19/2020 11:11 AM
5 degree engine mounting wedges. Don't trim out past the point where it stats to wiggle a bit. Stainless prop. What year Mag, front or rear trolling motor batteries?
https://www.ebay.com/p/1611840737?iid=291557951034&chn=ps&norover=1&...
Anything special or difficult with installation?
I have an '06 E Mag with 60 Suzuki 4stroke - I get 31ish by myself or loaded with 3 guys. Unloaded it starts to porpoise with any trim, but with the weight of buddies up front I can trim up without porpoising. It hasn't bothered me enough to take action on, but I would entertain any easy $50 fix. |
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Posts: 32801
Location: Rhinelander, Wisconsin | Easy to do, place between the bracket and transom as instructions will offer. Fresh silicone seal on the boats and you are good. |
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Posts: 32801
Location: Rhinelander, Wisconsin | miket55 - 4/5/2020 9:54 AM
sworrall - 3/23/2020 10:57 AM
5 degree wedges and a stainless prop will help a lot.
Thanks much for the advice, wedges are ordered... one more question..
Current aluminum prop is 14X11 3 blade, and runs 6000 rpm/ 29 mph. WOT. stay with the same pitch or change?
Again thanks for the help!
Same pitch stainless to 1 pitch up. |
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Posts: 349
| miket55 - 4/5/2020 9:54 AM
sworrall - 3/23/2020 10:57 AM
5 degree wedges and a stainless prop will help a lot.
Thanks much for the advice, wedges are ordered... one more question..
Current aluminum prop is 14X11 3 blade, and runs 6000 rpm/ 29 mph. WOT. stay with the same pitch or change?
Again thanks for the help!
Did the wedges help you with the porpoising?
I installed a set this spring and they didn't help at all, still porpoises before it cavitates when trimming up on plane. Moved the motor up 2 holes and still no change after that as well. |
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Posts: 32801
Location: Rhinelander, Wisconsin | You will not be able to use the trim much at all. if it's cavitating the motor is too high. |
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Posts: 3472
Location: Elk River, Minnesota | Hiya!!
First a couple of questions for both parties who have the porpoising issues...
What motor, gear ratio and Full throttle RPM's are you currently getting?
What prop are you running (brand, model, diameter and pitch)?
In most cases of a boat that is porpoising, the most likely cause is too low of RPM/over pitched propeller for the boat you have. I am not anywhere near as familiar with Tuffy boats as Steve Worrall so his suggestion of wedges is one I would do... If porpoising is still happening, I would bet the prop is too steep for the motor.
Lifting the motor off the transom is always good, as most are too low on the transom for optimum performance. There is a trade-off, though... The higher you go, you gain RPM's, but you are also increasing slip, so the offset may or may not work, and you will lose some handling capabilities at optimum trim (you'd have to trim down to make a good turn or the prop blows out).
As Steve stated, a steel prop will help as the bite of a good steel prop will always be better than a stock aluminum, which usually allows for raising the motor off the transom to get some RPM's back with minimal loss of handling.
If you can supply those values listed above, we can figure out the porpoising issue and get it gone...
Steve |
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Posts: 1209
Location: E. Tenn | UPDATE
Following Steve's advice, and Merc's recommendation, I went with a 14x12 Vengance SS 3 blade prop. That in itself took care of 90% of what I wanted to accomplish. I have not installed the wedges yet, and don't know if I will, but figured a good starting point. With the boat in the garage, I played with the tilt and an inclinometer, and found out what it takes to trim the motor up 5 deg. more or less. I'm now topping out at 33 mph @ 6000 rpm., with two adults, gear, and a full load of gas. More importantly handling has immensely improved, and the porpoising only occurs after trimming up the motor more than I normally would. I ran into a guy last week, with the same boat, motor, and prop, and he reported very similar numbers.
VMS... thanks for your interest, any other input you might be able to provide.. the motor is a 60hp Merc 4 stroke CT.. 2.33:1, mounted in the lowest hole |
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Posts: 349
| Motor: 2006 Suzuki DF60 Tiller
Gear Ratio: 2.42
Spec WOT RPM Range: 4700 - 5300 (this seems low, but it's what I've found for this motor)
Current Prop: Solas Amita 3 - 13.5 D x 15 P
Current WOT RPM: 5100-5200 (could get more with trimming up, but the boat starts to porpoise)
Negative 5° wedges installed - no help other than I can now trim back to 0° on plane
Originally mounted on the lowest holes, but I moved it up 2 holes and no change in porpoising. Cavitation plate is out of the water when on plane and boat handles great... No cavitation when turning.
2 batteries in the front half of the boat and my heaviest gear like the anchor is stored in the front storage compartment. I get less porpoising with passengers up front or a full tank of gas.
Performance: Good hole shot, WOT RPM are exactly in the spec and I get 30-31 mph WOT. I can trim up to the sweet spot at 3/4 throttle and cruise at 25 mph. If I trim up past 0° at WOT the boat starts to porpoise immediately until I trim back down.
My goal is to be able to trim up enough at WOT so I can get into the sweet spot and take all torque off the motor for easier steering.
Every other boat I have driven or owned, I can trim up at WOT until the prop cavitates or motor hits the RPM limit. This boat just starts to porpoise immediately.
I've considered a 13.75 D x 13 P prop but I'm hesitant to pitch down as that will most likely put me over max RPM and hurt top end speed.
I've considered a hydrofoil but my cavitation plate is well out of the water when on plane so I don't see how that would help.
Let me know if you need any other info, thanks!! |
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Posts: 32801
Location: Rhinelander, Wisconsin | I remember Jolins back in the day having a significant amount of issues getting the Mag to run well with a 60 HP Suzi where they had a 60 Merc 4 stroke dialed in. Not sure what the comparison in a 60 is between the props, but maybe VMS can recommend a Merc prop on an adapter for the engine. |
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Posts: 3472
Location: Elk River, Minnesota | Hiya,
I found your owners manual and 4700 to 5300 rpm is correct, so your numbers are really good there....
Can you possibly do me a quick favor? Can you take a straight edge and place it in different spots on the bottom of the hull right at the transom? I'm curious if the straight edge stays right on the hull at the rear where the transom meets the hull or if the hull comes up off the straight edge as it reaches the transom edge...
Prop-wise, the amita is a great prop, so I am going to hold off on considering another option....
I'm really curious about that back edge... If you can, maybe a picture or two of the straight edge on the hull?
Steve |
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Posts: 1209
Location: E. Tenn | Had a thought about the motor's shaft length, and what the actual length was from the transom (as measured from the centerline of the hull) to the propeller spline. On my rig, it looks to be 29", with the motor trimmed all the way down.. I wonder if the Suzuki in question measures up any differently? If it does, could that explain the difference in performance?
Edited by miket55 6/12/2020 10:43 PM
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Posts: 32801
Location: Rhinelander, Wisconsin | VMS - 6/12/2020 9:36 PM
Hiya,
I found your owners manual and 4700 to 5300 rpm is correct, so your numbers are really good there....
Can you possibly do me a quick favor? Can you take a straight edge and place it in different spots on the bottom of the hull right at the transom? I'm curious if the straight edge stays right on the hull at the rear where the transom meets the hull or if the hull comes up off the straight edge as it reaches the transom edge...
Prop-wise, the amita is a great prop, so I am going to hold off on considering another option....
I'm really curious about that back edge... If you can, maybe a picture or two of the straight edge on the hull?
Steve
Are you looking for transom angle or a rocker in the running bottom? There's probably nothing 'out of sorts' with the hull. Transom height is more than expected at about 20.5". The hull is a padded sponsoned V created by splitting an Esox LTD sponsoned hull and adding 10" width (as a flat) between the chines, and runs really well as a wheel boat with as much as a 135. Transom has about 3 degrees negative if I remember correctly. Rig it with a 90 console, and it's a rocket that can be trimmed up and run on the pad. I have always believed the tiller 60 model, insanely popular for years, had a problem being under powered as a 4 stroke powered tiller. It ran better with a 2 stroke 60. The pad is the 'issue' if you will. Just as the hull begins to lift under trim with a 60, it reaches a point where the engine/prop can't hold it. Make sense?
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Posts: 3472
Location: Elk River, Minnesota | Hiya,
Makes perfect sense...that was essentially what I was wondering about as to whether or not the hull might have that issue. I figured the tolerances would be really tight on that end.
Knowing that thought can be put to bed, so to speak, the only thing I can think of here would be to find a prop with better tip cupping, or have some tip cupping added to the current propeller. Not sure how well that would work with aluminum, but a steel prop would be able to be modified to make it work. Being the lower unit can handle a larger prop, more options are available for designs, but my gut says the pitch would be too high in those options. I'll do a bit of research to see what I can find out both on cupping an aluminum prop a bit, but also some options in steel.
Steve
Edited by VMS 6/13/2020 8:16 PM
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Posts: 349
| Getting back to this after the weekend. I got some poor quality pictures of the hull in my poorly lit garage, but sounds like they are not needed now.
Sounds like it may be an underpowered problem which is compounded by the fact that the Suzi df60 is a super heavy 4stroke @ 335 lb dry weight.
Question: what's up with the low max RPM rating on the DF60? It's same block sister, the DF70, is more traditionally rated at 5,200-5,800 WOT RPM range. |
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Posts: 3472
Location: Elk River, Minnesota | Looking at props,
the mercury spitfire 4 blade in a 14 x 12 might not be a bad option to consider trying. This is a 4 blade prop which I believe should still give you good holeshot, and it should hold the boat up better overall as it is steel. The 4th blade would help with bite, and going down in pitch while going up in diameter will help as well.
This is a rough estimate and is by no means going to be perfect, but I would think this would be close in RPM's for you. Going to a 14" diameter, you would be losing about 200 RPM, Going steel, another 200 RPM and going to a 4th blade another 200 RPM. BUT...going down in pitch by 3" should be roughly about 600 RPM's back up, so your top end should be fairly close. I believe this prop has a little better blade design than the vengeance 3 blade as that is basically a black max prop made of steel...a standard prop without much more to it other than to be decent for an all around prop with more durability than the black max.
Steve |
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