New '05 26M Owner - Hoping for some guidance.

NYharleyrider · Post by **NYharleyrider** » Tue Oct 12, 2004 4:59 am

Hi everyone... I'm brand new to this board and just purchased my first powersailer. '05 26M

I've spent the last couple of days reading your Q's and A's and I must say... you all seem like a wonderful group of people here and I'm happy to be a part of this site.

My main question is about motors and props.

I'm considering the merc big foot 60hp for my M. If I go with the big foot what is the best prop for the motor to achieve maximum performance.

Moreover - since I'm spending the money should I consider a 70hp which is Macgregor's highest recommendation.

Will a seventy hp with a standard lower out perform a big foot 60 with its larger sized lower... I don't know.

I guess what I'm getting at is if you had the choice to re-power your 26x or m what is the very best 60 or 70 hp motor and prop combo I should consider for my boat to achieve the greatest speed.

Additional questions pertain to GPS and Auto Pilot...

I'm definitely planning on purchasing a gps unit too.

There are so many different types which one is considered best for sailing and which auto pilot works best with a 26M... and can the gps and auto pilot work together if you so desire.

I'm from the North East (Rochester, NY area) and will mostly be sailing on Lake Ontario if that makes a difference.

I'd like to say in advance to those who respond, thank you for your input.

If some of you would like to talk over the phone and share your thoughts I'd be happy to hear from you too. 585-594-5860

And finally, if any of you are from the Rochester, NY area (or near by) I'd love to find other X or M owners to enjoy the Season with next Summer.

Thanks for your time and I look forward to your responses.

Brian.

mike · Post by **mike** » Tue Oct 12, 2004 5:11 am

Regarding autopilots, take a look at this thread from a day or two ago...

http://macgregorsailors.com/phpBB/viewtopic.php?t=1521

In terms of interfacing it with your GPS, this is a piece of cake. You connect a couple of wires from the GPS (NMEA out) to a couple of terminals on the autopilot (NMEA in). Then, you can set your GPS to navigate to a waypoint, and tell the autopilot to follow it. That's it!

--Mike

Mark Prouty · Post by **Mark Prouty** » Tue Oct 12, 2004 5:58 am

Welcome!

Try this thread regarding engine selection:

http://macgregorsailors.com/phpBB/viewtopic.php?t=1522

Moe · Post by **Moe** » Tue Oct 12, 2004 6:25 am

If you go with the 60HP Mercury BigFoot, I'd select the 14" X 9" pitch Black Max Prop. The motor's max rpm is 6,000 and the gearing is 2.33:1. Assuming 9% (.09) propellor slip, the predicted speed should be about what a lightly loaded M should be capable of with this horsepower, i.e. 20 mph.

Maximum RPM/Gear Ratio = Prop RPM

Prop RPM X Pitch = Inches Per Minute

Inches Per Minute/63360 = Statute Miles Per Minute

Statute Miles Per Minute X 60 = Statute Miles Per Hour

Statute MPH X (1 - Slip) = Speed After Prop Slip

NYharleyrider · Post by **NYharleyrider** » Tue Oct 12, 2004 6:52 am

Moe...

Thank you for your expertise. The info you provided was very helpful, but the follow up question still remains. Would I be better of with a Big foot 60 or someone elses brand of a 70 hp motor to achieve noticeably higher speeds... or would the differences be negligible.

A request to would be responders.... please don't answer with links to other postings. I've read over all of the posts regarding my questions (that's how I was able to narrow down my choice to a big foot) but in the other postings I didn't see people discussing prop size and motor size as one important consideration.

I realize I have a lot to learn, and honestly, it would be more helpful for me to read answers to my specific questions. Thanks again.... Brian

Paul S · Post by **Paul S** » Tue Oct 12, 2004 7:13 am

I would be careful of oversizing the motor on the M.

The transom is not that large compared to the X. Our Honda 50 is tight in there. If the case is too big..you might (will) have boarding issues.

Take a look at my site (www below) for the mods I have done. More to come too.

Not sure who rigged your boat..but I have had nuts falling off this boat like leaves falling off the trees in the fall. Double check all the fasteners on the boat. Check the steering linkage was installed correctly, especially inside, make sure it is not too tight. Almost nothing was installed correctly by my rigger.

I would just be wary about a larger hp motor putting stress on the boats transom. The boat appears to be built well...I am sure it will take it...but I would not go more than 50. Not sure how much performance improvement there is for the cost/weight/size penalty. Your call. I would try and see one on an M before you buy.

If there was a problem with an M...we have run into it...just ask if you have any questions.

Paul

Terry · Post by **Terry** » Tue Oct 12, 2004 8:14 am

I have the 2003 26M with a 50HP Honda (205lbs) and 4 X 11.5 X 9 Prop. This combination works quite well and I get 20mph at 6000rpm lightly loaded. I did a fair amount of research on propellers and can provide links that specialize on the topic. If you look under Performance And Tuning heading you will find a 3 page thread on propellers. As far as going for the 70hp engine, consider the extra money and weight you are trading for only a few miles per hour increase in speed. (24MPH) Those 70's are large & heavy and cost a few thousand $ more, $ that can be better spent on other options, if you have a need for speed get a power boat. IMHO a smaller engine (50-60) matched with the right prop (you may go thru a few props to achieve this) will more than meet your needs on the 26M.

NYharleyrider · Post by **NYharleyrider** » Tue Oct 12, 2004 8:54 am

This is some good info and I thank you guys...

My main thought was to go with the big foot 60 matched with the right prop. I'm not really looking to go up any further in size. I just wanted to make sure I wasn't giving up anything either. If you understand what I mean.

Harry van der Meer · Post by **Harry van der Meer** » Tue Oct 12, 2004 9:20 am

You may also want to consider engine reliability. I have the Honda 50 on my X and I am very happy with it. There are many of these units out there with proven long term reliability.

Post by **kmclemore** » Tue Oct 12, 2004 10:16 am

Good point, Harry.

And Brian, you should also consider local parts and service availability. I know it's been a bear to get a Tohatsu worked on within 25 miles of my home, for example.

Dimitri-2000X-Tampa · Tue Oct 12, 2004 10:52 am

Welcome Brian.

To offer a counterpoint on Moe's recommendation of a 14X9, I would only recommend that if you are planning to be very heavily loaded most all the time. For example, if you plan to motor around with the ballast full and 4+ people on board most of the time.

I have a 50HP Bigfoot and it will hit 5900 RPM with a 14X10 when the boat is lightly loaded. RPM's will drop to about 5500-5600 with heavy loading (ballast full). The WOT range on my 50 is 5500-6000 so I believe the 14X10 is the exact right prop for the 50. With 10 extra HP, you should not need less pitch, in fact, its possible that a 14X11 would be the way to go if you are not heavily loaded.

As for motor size, it really depends what you are into and where most of your boating will occur. If you are the type who will go slow most of the time regardless of the conditions, then even a 40 would probably be enough (although I wouldn't recommend putting less than a 50 on it..even if just for resale reasons). Personally, I do not have enough incentive to repower at the moment, but if I did, I would go for a 90-115 and do transom reinforcements. This would infringe on your open transom though so if you will be doing a lot of stern-to beaching, that is something to keep in mind. I start and finish every cruise on a very protected part of Tampa Bay so I could use the extra speed. This is about 7-8 miles of roundtrip "transit" distance to get into open Bay. To get out to the Gulf is over 30 miles so cutting an hour off of that trip in calm conditions is also appealing.

Moe · Post by **Moe** » Tue Oct 12, 2004 11:02 am

Whether or not performance is "adequate" is a personal and subjective judgement. I believe that until you get to a relatively lightweight 90HP, like the Tohatsu TLDI or Evinrude E-Tec, the differences will be minor.

It appears the majority here may feel that the Mac hull, even the X, probably isn't really planing with a typical 2 person load, until above about 23-24 mph, speeds beyond the capability of 50 HP, and probably even 60HP BigFoot. However, most planing hulls are quite deep-V forward, and don't approach their final stern deadrise angle until about 2/3 of the way back to the stern. When planing, the boat is riding on the flatter aft bottom. The Mac hull gets flatter much more forward, perhaps 1/3 of the way back to the stern, so a conclusion that the Mac isn't planing below these speeds, based on an observation that so much of the bottom is in the water, may not be correct.

Planing means that the peak of the boat's bow wave is at or aft of its center of gravity. One typically feels the boat nose over as it gets on plane. At slow speeds, the bow wave is short, and several bow waves move down the waterline. As speed increases, the bow wave grows in length and height, meaning there are fewer bow waves along the boat. At some point, you're down to two bow waves supporting the boat. This is typically the planing hull's displacement hull speed.

As speed increases beyond this, the second wave moves back aft of the transom and the boat is left with one bow wave to climb. The wave height is determined, in part, by the boat's angle of attack over the water surface. The higher the angle, the greater the bow wave height, and the more horsepower needed to climb the bow wave. That's why, on take-off with a planing hull, we trim the motor all the way down, to lower the bow and raise the stern, and get on plane quicker and easier (actually the trim is fighting the prop's offset from the surface trying to lift the bow). Once on plane (i.e. no longer climbing the bow wave), the load on the motor, as well as fuel consumption, drops off.

Although the rpm at which the motor reaches its torque peak is among other factors that influence fuel efficiency, many, if not most boats get their best fuel economy just past minimum planing speed, and it's sometimes as good as that achieved at the hull speed off-plane. However, that economy dips between hull speed and planing, when the boat is working harder climbing the bow wave. We see this dip in boat tests where a fuel flow meter is used. However, these meters aren't frequently used with smaller outboards because their fuel flow in most of the operational range is below the minimum needed for the meters to read accurately.

The depth of that fuel efficiency dip depends, in part, on the height of the bow wave, which depends, in part, on the angle of attack. Other things being equal, a heavier outboard increases this angle, making the bow rise and subsequent rollover onto plane greater, while a lighter outboard will allow the boat to come up on plane with much less noticable bow rise and rollover. Operating in the no-man's land between displacement speed and planing speed, a lighter, less powerful motor can often do the job of a heavier, more powerful motor using more of its capability to fight the larger bow wave, and generating more wake.

Whether or not the Mac hull reaches actual planing speed at wide-open throttle (WOT) is largely irrelevant with the smaller motors, if you're going to limit cruise RPM to about 75% of redline, and only use WOT occasionally for short periods, in order to acheive longer engine life. In other words, you're going to be operating at sub-planing speeds, and at these speeds, motor (actually stern) weight is a big factor. That's why we see the very lightweight, small displacement Honda 50s, even with their smaller diameter props, performing about as well as some heavier, larger displacement four-strokes.

Heavier motors present additional stress on the not only the transom, but sometimes on the boat bottom as well. Trailer bunks should extend slightly aft of the transom, to carry the weight of the motor. Not having this support can result in the bottom of the boat developing a curve downward over time, aft of where the bunk ends. The Mac trailer provides no support for the transom, with its aft bunk significantly forward, which gives the motor more leverage to bow the bottom. I wouldn't put a significantly heavier motor on a Mac unless I got a trailer that supported the full length of the bottom.

For me, the huge jump of an additional 100 lbs of weight on the stern doesn't justify the additional 10HP of the DF70 Suzuki, much less the DF60. I understand and respect Frank C's logic in choosing the latter, but it doesn't work for me.

When you get to the point the motor can definitely plane the hull at about 75% or less of redline, you open up a whole new mode of operation for the boat. I believe, especially with their relatively lighter weight, the above mentioned 90HP two-strokes may be able to do this.

This is why I recommend the Merc BigFoot EFI, or the Yamaha version of it called the High Thrust (as long as it's the EFI). And I agree about support being a factor. While there are a good number of Merc and Yamaha support sources locally, the closest I've found for my Suzuki is over an hour away.

Finally, a word of warning, or disclaimer if you will. MacGregor states, in print, "We limited the engine size to 50 hp for a number of reasons." We have only heresay that at least one dealer claims that if they do the installation, MacGregor will not void the warranty due to the greater horsepower. I'd insist on something in writing from MacGregor on this, or at least something in writing from the dealer stating that if they do the installation, they will provide the hull warranty if MacGregor does not.

This is common problem in the Harley world. Harley sells a ton of EPA violating performance equipment, but specifies it's "for off-road use only" and that it may void portions of the warranty. Many dealers tell customers the same thing, that Harley won't void the warranty if the dealer does the installation. That's usually true even if the customer does the installation, however, there are cases, even where the dealer did the installation, that Harley has claimed the parts were responsible for the problem, and not covered them under warranty. The same happens at some automobile dealerships.

The odds you'll have to make a hull warranty claim aren't high, and decrease with motor weight. I do like option of slapping a 50HP cowling on the Merc BigFoot 60 should that become a problem, even though it weighs no more than the 50HP BigFoot MacGregor used on their demo M.

--
Moe

Dimitri-2000X-Tampa · Tue Oct 12, 2004 12:57 pm

It appears the majority here may feel that the Mac hull, even the X, probably isn't really planing with a typical 2 person load, until above about 23-24 mph, speeds beyond the capability of 50 HP, and probably even 60HP BigFoot.

Not quite accurate. We had quite a lengthy discussion and poll in this thread a few weeks ago. At the time of this note, only 22% believe that the Mac hull is not planing. I personally think that there is overwhelming evidence that that Mac not only planes with 50HP but does this well under max throttle (at around 10 knots which is only about 2/3 of max speed)..I think it probably planes with 40HP too but I don't have first hand experience.

Now Moe, what is your secret to getting so many people to vote in a poll???

Dimitri-2000X-Tampa · Post by **Dimitri-2000X-Tampa** » Tue Oct 12, 2004 1:10 pm

To offer a counterpoint to Dimitri's counterpoint

His lightly loaded boat that reaches 5900 rpm with 50HP and a 10" prop is a 26X, not an M.

Your point is well taken. I didn't know the bigfoot had a governor. Mine is the 2000 model which is the last year of carbs. I'm pretty sure there is no throttle linkage type governor so it would have to be in the ignition module if it exists.

With a lightly loaded boat and the extra 10HP, it is worth mentioning the redline risk. If there is no governor, then you may damage the motor, but with a governor, you are still going to lose power ... perhaps that whole extra 10HP that you just paid good money for...since it would kick in at the top of the RPM curve.

Also, is the 26M really that much heavier? I knew they added 300lbs of fixed ballast, but I also thought they compensated by removing some other weight to make the net difference smaller than 300.

Anyway, its hard to tell when you are down to fine 1 inch type differences, but I still think the choice on a 60HP for a "first" prop should be between a 10 and an 11.

Terry · Post by **Terry** » Tue Oct 12, 2004 1:22 pm

Moe, You sound like an encyclopedia, so maybe you can shine some intelectual light on this one.
How does hub size affect thrust? Those 14" props likely have a larger hub size than the maximum 12" prop Honda hubs. Does the 12" honda prop have the same blade surface area as the 14" prop? Does the larger hub reduce blade thrust? How about the number of blades, I have two: a 3X10.75X13 Hustler & 4x11.5X9 Solas. They both get high RPM's the 3 blade hustler gets about 5900 light laod and the solas hits about 6200 light load. For some reason the Solas gets 20mph but the hustler barely makes 16-17mph, I doubt the 300 rpm difference is it, I am more inclined to believe that there is a lot more slippage with the hustler due to the smaller diameter and blade surface whereas the Solas has a bigger diameter and 4th blade for more surface therefore more thrust and less slippage. I also highly doubt that any MacGregor gets anything near as low as 9% slippage, more likely 20% or more. There is a link to a prop calculator under my old propeller thread to calculate slippage with and I discovered I was way up in the 30-40% slippage range when I was loaded. You are right about one thing, bigger diameter & smaller pitch is the way to go on these big boats. The local here dealer uses 3X12X10.25 on the honda and gets pretty good results. Sure would like to see more test results on props for this boat.

MacGregorSailors.com

MacGregorSailors.com

New '05 26M Owner - Hoping for some guidance.

New '05 26M Owner - Hoping for some guidance.

Motor & Prop

Hub Size