Signifcant difference between 50 & 60 HP outboard?

[dlandersson]

It's well know that a mans dreams should exceed his grasp, or what's a heaven for?

Got my 97X with it's 50 HP up to 16 mph again today. Is there much of an improvement with a 60 HP outboard?

[DaveB]

Maybe 1.5-2 mph diffrence for the Yamaha or Merc, big foot. E-tec 60 may get you to 20 mph on the MacX.
Thats with a 700 lb load, People, gear added,fuel,water etc.
Well known dream Man would get a Suzuki 90 hp. Speed for need.
Dave

It's well know that a mans dreams should exceed his grasp, or what's a heaven for?

Got my 97X with it's 50 HP up to 16 mph again today. Is there much of an improvement with a 60 HP outboard?

[raycarlson]

biggest mistake i made was not buying the 90hp tohutsu tldi,i was trusting in the macgregor literature, which was all lies.

[DaveB]

How so? I don't see a motor type on your profile. What Literature are you refuring to?
Dave

biggest mistake i made was not buying the 90hp tohutsu tldi,i was trusting in the macgregor literature, which was all lies.

[dlandersson]

I was thinking a 60 HP Merc would be a fairly easy swap. Similar cables, etc.

What about a 60 HP Tohatsu?

Maybe 1.5-2 mph diffrence for the Yamaha or Merc, big foot. E-tec 60 may get you to 20 mph on the MacX.
Thats with a 700 lb load, People, gear added,fuel,water etc.
Well known dream Man would get a Suzuki 90 hp. Speed for need.
Dave

It's well know that a mans dreams should exceed his grasp, or what's a heaven for?

Got my 97X with it's 50 HP up to 16 mph again today. Is there much of an improvement with a 60 HP outboard?

[Whipsyjac]

20% by my math Maybe you should've asked "Who has a xx year 60hp on a 97 , and what is your top speed?" Then let me know 'cause I've got a 96 with a Merc 50 4 stroke. PO claimed to have hit 23MPH with empty boat, just him and his son doing speed runs on a flat lake. I really like the idea of the Yamaha F70 which weighs in a 250lbs(great power to weight ratio), not happy about the idea of spending 10 boat bucks after taxes and install.

Willy

[dlandersson]

With that in mind...what's a good place to look for used outboard engines in NWI? Yakaz? Craigslist?

20% by my math Maybe you should've asked "Who has a xx year 60hp on a 97 , and what is your top speed?" Then let me know 'cause I've got a 96 with a Merc 50 4 stroke. PO claimed to have hit 23MPH with empty boat, just him and his son doing speed runs on a flat lake. I really like the idea of the Yamaha F70 which weighs in a 250lbs(great power to weight ratio), not happy about the idea of spending 10 boat bucks after taxes and install.

Willy

[mastreb]

So in reality, while you're getting 20% more horsepower, that doesn't equate to 20% more speed or anything like it. doubling the speed requires 4X the horsepower. 20% more horsepower roughly equates to 10% more speed, or about 1.6 knots at WOT.

I have an ETEC-60, and I can confirm that I get 18 knots max with an unloaded boat and two people. That's 10% more speed that you're getting out of a 50hp.

I've got 30 hours on my motor in 18 months of use (because I literally go sails up the minute we're clear of the marina). Maybe a 1/2 hour of that time was spent at WOT, mostly just to show off to friends. So that's 2% of the my engine's usage so far.

Do I care about the difference between 16 knots and 18 knots for the 2% of the time I've been WOT? Not at all. Would a 50hp do everything else I've asked my motor to do? Of course it would.

This is how I learned to stop having 90hp envy and just be happy

[Ponk]

I take my 98x up to 16 knots or so with the original Yamaha 50 four stroke with no real effort (even in a medium seas). I don't find a lot of difference in speed with loaded or unloaded, I do notice that extra weight in the bow really helps achieve higher speeds (on calmer days). With the nose down, I find she planes much better and leaves much less wake. So if I am heading out in the morning to get somewhere, I put all liquids at the front of the V-berth, the extra batteries in the forward hatches, everything that fits. I can always trim-up the engine and raise the nose if I've overloaded it. But when I raise the sails, I bring the heavier stuff back to the center so its easier to hold a line.

Also, I learned from local Yamaha mechanic that running at high RPMs (above 5000) isn't great for your motor. He said topping out at 6000 rpms is the right top setting for the motor and is okay for urgent situations, but cruising for prolongued periods of time should be kept around 3000 rpms or 50% of your capacity. If you are always running at 100%, he says you're more likely to burn out the motor. So since then, I try to keep the RPMs down, but it's hard to do. Even knowing gas consumption is somewhere like 3 times more at 6000 compared to 3000.

And to confirm what Whispyjak said, he said the new Yamaha F70 is the same weight as the old 50 fourstroke. I didn't know 250 lbs was the magic number for weight, although it doesn't make a difference to me. I don't have 10 boat bucks for that either. But after spending close to thousand dollars replacing the tilt motor, I was feeling tempted. In for a dime....

Does anyone know about props (pitch, size and number)? I was told that your prop's pitch provides speed at the expense of power. I asked the mechanic about that and we discussed trying a different pitch, but we couldn't read the pitch angle on my prop and he was reluctant to change it without knowing that or the designed hull speed. I got the sense I was out of his comfort zone. I don't really need the power. If I am out with the family, I am not inclined to go fast. But when I am by myself going to the fishing grounds, I'd like to be there sooner than later.

[mastreb]

It's pretty simple to find the right prop for these boats. The correct diameter is between 12" and 14" for all outboards. this gives you the proper torque for a boat of this size.

The correct pitch depends on your final drive gearing and your typical weight load, but the way to find it is to determine the RPM of your motor at WOT with the prop you have and compare it to the ideal RPM range for your motor. Usually you will be low, and typically the correct top end range will be expressed as a range, such as 5600..6000.

Target the low end of this range with your typical weight load onboard. For ever 200 RPM you are below the limit, decrease 1" of pitch. If you are high, increase 1" of pitch. You target the low end because you don't want to empty the boat and wind up over-revving your motor at WOT.

For example, if you have an Etec-60 and find that with the factory stock 13.75x13 prop you are running 5200 RPM after a few mods and your ger, and you want to get back to 5600 RPM, you need to subtract 2" from pitch, which puts you in a 14x11. This is a VERY common prop for typically loaded Macgregors. You may go to a 14x10 or even a 14x9 depending on your weight and final drive gearing however (most outboards have a 2:1 final drive, ETECs have a 2.66:1 to convert their higher native two-stroke torque to horsepower).

So run it WOT, record your RPM, look up the low end of ideal RPM WOT, do the math, and then buy that pitch in as close as you can get to a 14" prop.

Simple.

[ON EDIT] I do see people talking about 11" diameter props on BF50s running on boats. That probably works just fine on the flatter hull, but I'm pretty certain you'd want to be near 12" at a minimum on the deeper V'd to get the necessary torque to go reliably on a plane with a load. The smaller the diameter and the shallower the pitch, the faster the motor will run and the higher the RPM, which equates to more horsepower (top-end speed) versus torque (starting moment "hole shot" and rate of acceleration). Too small and you'll rev over the RPM limit for the motor routinely and you won't have the bite to put all the motor's power to forward momentum. Hole shot and acceleration are far more important than top-end speed in any boat IMHO because they can change maneuvering dynamics more quickly in a pinch.

[dlandersson]

A wise man indeed.

Do I care about the difference between 16 knots and 18 knots for the 2% of the time I've been WOT? Not at all. Would a 50hp do everything else I've asked my motor to do? Of course it would.

This is how I learned to stop having 90hp envy and just be happy

[Tomfoolery]

I do a lot of high-speed motoring, mostly pulling my son on a wakeboard, which he learned to ride behind my . In fact, wakeboarding was one of the main reasons for downsizing from a keelboat to the . That, and the ability to get to distance sailing grounds in hours instead of days.

Now I've got the 90 hp itch. Gotta talk the admiral into getting a bigger OB, maybe used, and hopefully selling the mint-condition BF50 to minimize the damage.

[dlandersson]

You can't just go down to Wal-mart, buy a 19" fan and mount it as a propeller?

I do a lot of high-speed motoring, mostly pulling my son on a wakeboard, which he learned to ride behind my . In fact, wakeboarding was one of the main reasons for downsizing from a keelboat to the . That, and the ability to get to distance sailing grounds in hours instead of days.

Now I've got the 90 hp itch. Gotta talk the admiral into getting a bigger OB, maybe used, and hopefully selling the mint-condition BF50 to minimize the damage.

[DaveC426913]

I'd be terrified of a 60, let alone a 90!

I don't know how the rest of you manage, but at anything over 9 knots, it feels like I'm riding on top of a beachball. I worry that other nearby boaters think I'm having a seizure at the wheel, or I'm trying to scare the bejeezuz out of them "He's going to port. Nope - he's going to starb- wait! port! Ahhh!"

[vkmaynard]

I'd be terrified of a 60, let alone a 90!

I don't know how the rest of you manage, but at anything over 9 knots, it feels like I'm riding on top of a beachball. I worry that other nearby boaters think I'm having a seizure at the wheel, or I'm trying to
scare the bejeezuz out of them "He's going to port. Nope - he's going to starb- wait! port! Ahhh!"

Hopefully you're kidding. At speeds under 8 mph you need a rudder down and a very small amount of center board. Then the boat handles ok. At higher speeds the X becomes more stable due to hydrodynamic pressure on the hull. A lot less beach ball feel.

FYI: Drag increases by the square of the velocity. So it is not a linear increase in speed with a linear increase in horsepower.

Victor