beene:
THIS SITE lists the Mercury 75, 90, and 115hp 4-stroke as having the same powerhead (just a different CPU).
they each have a dry weight of 399# (a real monster!).
the 75 and 90 list a 5,000-6,000 maximum RPM @ WOT. the 115 lists 5,800-6,400.
this info contradicts what you said above.
what manual are you reading???
Bob T.
"DāBob"
'02X w/ '04 90-TLDI (14" x 11 pitch)
Dinghy Motor: '06 2.5-Suzuki
Jackpot!
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Bobby T.-26X #4767
- Captain
- Posts: 906
- Joined: Mon Jan 05, 2004 10:48 am
- Sailboat: MacGregor 26X
- Location: Oceanside Harbor, CA
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Bobby T.-26X #4767
- Captain
- Posts: 906
- Joined: Mon Jan 05, 2004 10:48 am
- Sailboat: MacGregor 26X
- Location: Oceanside Harbor, CA
alrighty then...Here's the specs on the Mercaha 90 HP. This motor was the most popular on the Boston Whaler 170 Montauk for many years and wasn't rated for greater than 6,000 rpm. The Yamaha 90 from which it comes is also rated 5,000-6,000 rpm. If the 75 will pull the 13" prop to 4,500 rpm, the 90 will pull it to 5,000.
386 pounds on a boat designed for 260 or so is grossly overweight. Comparing a MacGregor 26 to boats with triple 300s is laughable at best.
A heavy weight off the transom balanced by heavy weight in the bow is nowhere near the same as having the same total weight centered. You have to consider the moment of the mass. Try stopping or starting two kids of equal weight on a seesaw both at the ends and near the point of pivot and you'll see the difference.
386 pounds on a boat designed for 260 or so is grossly overweight. Comparing a MacGregor 26 to boats with triple 300s is laughable at best.
A heavy weight off the transom balanced by heavy weight in the bow is nowhere near the same as having the same total weight centered. You have to consider the moment of the mass. Try stopping or starting two kids of equal weight on a seesaw both at the ends and near the point of pivot and you'll see the difference.
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aya16
- Admiral
- Posts: 1362
- Joined: Fri Feb 18, 2005 6:29 am
- Location: LONG BEACH CALIF Mac M 04 WHITE
most of my posts are laughable at least I hope they come off that way. as well as good info I like to try and put a grin on a face or two.
But Im sorry your wrong plane and simple. Grossly over weight is something that would imply something like I gave as an example, at best I think you mean slightly heavier then Mac wants you to put on the boat. with the difference in manufacturers weight in hp classes 100 pounds doesnt mean a thing. or even 200. I doubt Mac would design a transom (or what ever it is you imply is too weak to handle the extra weight) to shear off if an extra 100 pounds was added. try this: with the boat on the water floating, go sit on your engine and see how far down the mac goes. you dont have a mac so ill tell you. 0 it doesnt budge.
The difference in weight distribution is simple, if the boat plows you move the stuff back if the bow rides too high you move stuff forward. if the boat is too heavy you toss the two kids and the seesaw off the boat....
But Im sorry your wrong plane and simple. Grossly over weight is something that would imply something like I gave as an example, at best I think you mean slightly heavier then Mac wants you to put on the boat. with the difference in manufacturers weight in hp classes 100 pounds doesnt mean a thing. or even 200. I doubt Mac would design a transom (or what ever it is you imply is too weak to handle the extra weight) to shear off if an extra 100 pounds was added. try this: with the boat on the water floating, go sit on your engine and see how far down the mac goes. you dont have a mac so ill tell you. 0 it doesnt budge.
The difference in weight distribution is simple, if the boat plows you move the stuff back if the bow rides too high you move stuff forward. if the boat is too heavy you toss the two kids and the seesaw off the boat....
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aya16
- Admiral
- Posts: 1362
- Joined: Fri Feb 18, 2005 6:29 am
- Location: LONG BEACH CALIF Mac M 04 WHITE
I like a good discussion as well as any guy so.
Heres where the calculations made to prove a point are wrong. to put a weight at one end of a board that is sitting on a center folkel point then put same weight on the other side but slightly closer to the center, of course the weight on the very end will over power the other side. But here is where the example is wrong to begin with. The Mac sits flat in the water with no center folkel point, just as if the board were now laying flat on the grass.
now water does give some but not like a support in the center. moving a small amount of weight around in the mac does not effect the 26 feet flat surface fore and aft, it will side to side. to effect the mac fore and aft you have to move a lot of weight, 5- 6 hundred pounds I would guess, say three adults standing on the bow would push the bow down a couple inches right? so how can 100 pounds make a big diff. in the rear, that happens to be the widest part of the boat anyway. and the most stable.
it cant...Iknow Iknow someone is going to say the mac isnt flat on the bottom. But it was an example.
Heres where the calculations made to prove a point are wrong. to put a weight at one end of a board that is sitting on a center folkel point then put same weight on the other side but slightly closer to the center, of course the weight on the very end will over power the other side. But here is where the example is wrong to begin with. The Mac sits flat in the water with no center folkel point, just as if the board were now laying flat on the grass.
now water does give some but not like a support in the center. moving a small amount of weight around in the mac does not effect the 26 feet flat surface fore and aft, it will side to side. to effect the mac fore and aft you have to move a lot of weight, 5- 6 hundred pounds I would guess, say three adults standing on the bow would push the bow down a couple inches right? so how can 100 pounds make a big diff. in the rear, that happens to be the widest part of the boat anyway. and the most stable.
it cant...Iknow Iknow someone is going to say the mac isnt flat on the bottom. But it was an example.