26M w/ 90 HP

[tom clayton]

you have a 90 hp would that prop be effective on my 70hp? is the output shaft the same on the 70 i believe it is but not 100% sure i think the 70 80 and 90 are only different by piston size.

[Terry]

Very interesting Victor

I was not aware that this was possible and, regretfully, I very much doubt if this is a service available in my area.
Your comment is an eye-opener for me; thanks.

Octaman

I believe if you look around you will be surprised at what service is available. I had to do a bit of scouting myself and was able to find a prop shop to get my Solas re-pitched. They not only can re-pitch your prop higher or lower but can also repair the blades of some very damaged propellers. The fellow I took mine to had a shelf full of props to be repaired and I asked him if it was possible to fix some of them that looked totalled and he said certainly, then reached for one of the worst ones, picked it up and said, 'I can restore this one back to it's original condition.' It is amazing what those guys can do. My four blade Solas is now custom pitched and matched to my 26M.

[Stefan]

Octaman,
I guess I cAn say this is enough for me.
First of all I accepted that fact that is not as fast as under the same motor. That is covered in Victor's thread.
But the 90hp and 4 blade prop do the trick, it has enough power to pull a crowd


I even had 4 people in one tube and 2 in another, without losing much speed, still making about 18-19 knots.
Actually, being able to do that was one of the reasons I got the
The max speed for me is not so important since I haven't been on the extended trip yet, when I'd have to go far enough and need to get back fast.
For me the extended ride on plane speed gets very bumpy and uncomfortable, with lots of water spray, if the surface is not near flat, and the Black Sea in my area is rarely like that. I prefer 6-10 knots. Right now I am concerned about the fuel consumption rate. Since I can burn at least one tank at once and see how far it takes me, I decided to add a fuel flow meter. Since I have the Lowrance HDS-5 unit, I bought the EP-60R fuel flow sensor but have not set it up yet. It'd be interesting to find out the most economical speed for my setup, then I would be more comfortable to plan longer trips and know when to turn back
If someone can share the practical burn rate for that engine it'd be interesting to hear, and than compare.

PS: I also regretfully discovered that re-pitching is not even heard of in my area, that's why I went for the best possible match of the prop, and that turns out to be the SS one, even though more expensive, I still had to modify the HUB, but that was doable. If it was my choice I would also stay with the biggest diameter (14) and test the smaller pitch one by one. I know I would be fine with 3x14x11, but I wanted the 4 blade prop for the above discussed reasons, and I think in my situation I got the best match.

[vkmaynard]

Wow, great picture! Is that really a sailboat boom in the picture??

Victor

[vkmaynard]

Victor, you have the 2001 Mac.X and I the 1997 model.
I have tried to get the width of the DF90A but without results. Max. width I can have is 16 inches as the boarding ladder will hit engine if raised. What is the width of the 90? I now have the Honda BF50 and that has 14.7 width and ladder clears by 1.25 inches and boarding 14 inches between rudder up and engine.
Dave

The measured width is 18.25". Smaller than the previous 2008- 90s. I would not let moving the ladder stop you if you are intending to add a 90. What's another hole in a Mac?

Victor

[Octaman]

WOW Stefan! Great photo! Very convincing! Love it!
I was hoping you woud chime in.

18 to 19 knots cruising speed is a dream . . . for me. I think I would be very happy with that. What are your rpms at this speed?
Can you please confirm the type of 4-blade prop you are using? I think you have mentioned this before but I have not made a note of it, it seems . That would be most helpful if I eventually decide on the Suzuki DF90A motor.

I also very much look forward to hearing of your observations regarding fuel consumption. This is all very helpfull. I thank you all very much.

---------

I think everyone agrees that the Macs suffer from an inadequate steering set up. Especially when you put a bigger, heavier engine on (> 50hp). You may like to have a look at my steering mods (3 in total)that have worked very well for me. For those that go for the bigger engines, I think it is a 'must'. Perhaps the most significant upgrade I have done to my MacM. It really does transform the boat and makes it a lot safer.

Here is the steering upgrade thread: http://www.macgregorsailors.com/forum/v ... f=8&t=5130
and here are the three mods,

Part 1 Double steering cables http://www.macgregorsailors.com/modt/index.php?view=662
Part 2 Aligning rudders http://www.macgregorsailors.com/modt/index.php?view=663
Part 3 Eliminating rudder stock play http://www.macgregorsailors.com/modt/index.php?view=665

Hope you find this useful.

Octaman

[Stefan]

Victor,
you're right, it a boom with lazy jacks. I put the boat on AP and got up to the mast to make a quick picture from my cell phone.

Octaman,
I guess it was good timing for me to look at the forum again, I've been busy lately and haven't checked in here for a few months.
The prop I use is Solas RUBEX HR4 9453-135-13 (thats 4x13.5x13) Stainless Steel Boat Propeller with RBX125 hub(I had to modify it, it's not the correct one for this motor, the correct one wasn't even available at the moment by the Solas dealer ).

Thanks for sharing your mod, it looks impressive, it might be a good thing to do some time in the future, when I get to the point when I couldn't live without it. For now it seems like I can deal with what I have from the factory. At the moment I am more concerned with additional improvements to the daggerboard. I wanted to deal with excessive heeling when sailing, I already added about 20lb, but need to work on it some more.
Regarding the fuel efficiency, may be Victor can share his observation on this subject, until I set up my sensor and see what the HDS5 thinks about it.

[vkmaynard]

Stefan what is your WOT no ballast RPMs? With a couple of crew while not towing the Queen Mary?

[Stefan]

I didn't have a chance to test with just 2 on board, but with 5 or 6(can't even remember) I saw about 6100-6150 may be. No calm sea either. So, considering no re-pitching option for me, I think it was pretty good shot, going for this prop.

[vkmaynard]

Sounds perfect.

[elvatoli]

Does anybody knows the prices for the motors ?. New and installed ?
Tohatsu 2 stroke 50hp, 75 hp, 90 hp
Suzuki 70 hp, 90 hp
If I can pay $1000 less than what the local dealer have offered ($5800 50hp, $7500 75hp, tohatsus), I can travel anywhere in Texas to get it.

Thanks
Hector
Port Isabel, TX

[mallardjusted]

Without dickering, in our area I was given a price quote of $8200 for the 75 tohatsu. Installation and cables for approx $500 to $700. Suzie about the same price.

One that on paper that looks interesting is the new Yamaha 70. Costs are over $1000 less. Yet the motor weighs 260lbs for a 4-stroke 60.8 cubic inches! That compares to 243 lbs with 40.8 ci for a Suzie 50 ......... only 17 lbs difference! Has anyone out there looked at this outboard?

[Stefan]

today I was able to do the test run with just two people on board, no ballast and no load, even sails, boom and cushions were taken out to garage for winter storage, although didn't put down the mast yet.
The weather was perfect also.
So, I was able to make 21.7 knots at 6300-6400rpm WOT.
at 5000rpm I was running 16 knots, and at 2000rpm it was 5.5 (if not mistaken)
I like the results.

The bad thing is that at about 20 knots the water starts getting pushed through the daggerboard trunk and messing around the cockpit. I was surprised that it was still possible after I enlarged the daggerboard size (mostly thickness) to match the trunk size. It was so loose at first.

Another frustration was that I still couldn't set up the Lowrance EP-60R fuel flow sensor to an HDS-5 unit. I've tried everything in the manual to make settings in the network but it just doesn't get recognized by the HDS. May be new software would help, just downloaded it from Lowrance site. Too bad they don't have the phone number to call customer service, just an email.
It would be very interesting to see the actual fuel consumption at different RPM and speed, that was the main reason for putting the boat in the water, by the way.

[vkmaynard]

Stefan what is your altitude?

Sounds like correct prop the way you run your boat "empty". Is the 4 blade an improvement over the original 3 blade, or not?

At 400' altitude that sounds like the same top speed a friend was getting on his ETec 90 M in about the same super empty configuration.

Victor

[Octaman]

Stefan,

Thank you for sharing your experience with us. Very impressive numbers. I am convinced I have to repower upward from my already very good Suzuki 70 (1.300cc)
Hope you sort out your fuel flow sensor issues; I eagerly await to hear of your observations with fuel consumption.

I have to say I am impressed with the speed drop with a drop of rpm by 1.000 I would have expected less of a speed drop.
Would you say that the Mac is pushing water again at 16 knots compared to 19-20 knots on a plane?

I also think that under such light-weight conditions you should be targeting the higher end of max rpm at WOT. So, maybe there is still some room for improvemet as far as the prop goes; Victor, what do you say?

The bad thing is that at about 20 knots the water starts getting pushed through the daggerboard trunk and messing around the cockpit. I was surprised that it was still possible after I enlarged the daggerboard size (mostly thickness) to match the trunk size. It was so loose at first.

You may have noticed that the daggerboard is slightly shorter compared to the size of the trunk.
If when you raise your daggerboard you raise all the way up, the bottom end of the daggerboard is not flush with the hull. It sits a little higher creating a step in the hull. This step is what causes the water to rise and spurt out of the trunk.
It happenened to me with less speed until I found the remedy.

Put a mark on your keel lifting line and a second on the top of the coachroof so that when the two marks align you will know that the bottom end of the daggerboard is flush with the hull. When raising the keel bring it all the way up, then let out a little for the marks to align. You should have no water coming up the trunk in this position at any speed in relatively calm waters.

Having said this and in spite of keeping the bottom end of the daggerboard flush with the hull, it is possible that in very high seas (waves bigger than 2metres - which is probably above a force 6) and even though you will be moving at displacement speeds with your water ballast tank full for stability, in these 'extreme'conditions (for the Mac) you may still get a little water coming out of the trunk from time to time. But this will be rare and will be because of the difference of the height of the water, not the speed.
Hope I am making myself understood.

Octaman