Power Comparison - Moderated Discussion Areas

  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: The Whaler GAM or General Area
  Power Comparison

search | FAQ | profile | register | author help

Author Topic:   Power Comparison

Bosmass posted 11-19-2002 10:11 AM ET (US)
I am repowering a 17 foot SSL and weighing my options: Are the new fuel efficient 2 stroke motors more powerful than ones built in the early 1990? Is for an example, a 2002, 70 hp 2-stroke Mercury as powerful as a older 100 hp Mercury?
tabasco posted 11-19-2002 10:29 AM ET (US)
Go with more power ........you can always pull back on the trottle ......you never know when that extra power can come in handy in an emergency situation. I would always rather be overpowered than underpowered.The motor doesn't have to work as hard and thus will probably last longer.
Bosmass posted 11-19-2002 11:35 AM ET (US)
I agree with you on principal however, I've 'heard' that the new more efficient outboards are more powerful than their older equivalents.That is a modern 70 has the power of an older 100. Is this assessment correct?
Tom W Clark posted 11-19-2002 11:45 AM ET (US)
Bosmass,
No, a modern 70 hp outboard motor is not going to as powerful as a 1990 100 hp outboard.
What you may have heard is that powerhead rated outboards are more powerful than prop shaft rated outboards. In the mid 1980's the standard for rating an outboard's power was changed from measuring the horsepower at the powerhead to measuring it at the prop shaft where it really counts.
This difference may account for a 10% or 15% increase in power, but not a 30% increase.
Bosmass posted 11-19-2002 12:39 PM ET (US)
That's it, ok so now I change my search.. I'm looking for a 'modern' 90 hp, 2 stroke.. thanks for the information.
lhg posted 11-19-2002 03:26 PM ET (US)
Yes, I agree, you want 90HP for the boat. I'd go with Mercury or Yamaha, since there is no separate oil injection tank to locate somewhere in the boat, generally a headache. The Johnson is at a disadvantage in this respect. The Merc and Yamaha make for a nice clean installation. If you want to save a little, don't rule out the Merc 75, basically a detuned 90, and a pretty strong engine.
The Yamaha 70, although it looks the same as their 90, has a much smaller block.
Forget the Mercury 115, as it's no faster than the Mercury 90 on a Montauk. Don't ask me why.

Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.

Author	Topic: Power Comparison
Bosmass	posted 11-19-2002 10:11 AM ET (US) I am repowering a 17 foot SSL and weighing my options: Are the new fuel efficient 2 stroke motors more powerful than ones built in the early 1990? Is for an example, a 2002, 70 hp 2-stroke Mercury as powerful as a older 100 hp Mercury?
tabasco	posted 11-19-2002 10:29 AM ET (US) Go with more power ........you can always pull back on the trottle ......you never know when that extra power can come in handy in an emergency situation. I would always rather be overpowered than underpowered.The motor doesn't have to work as hard and thus will probably last longer.
Bosmass	posted 11-19-2002 11:35 AM ET (US) I agree with you on principal however, I've 'heard' that the new more efficient outboards are more powerful than their older equivalents.That is a modern 70 has the power of an older 100. Is this assessment correct?
Tom W Clark	posted 11-19-2002 11:45 AM ET (US) Bosmass, No, a modern 70 hp outboard motor is not going to as powerful as a 1990 100 hp outboard. What you may have heard is that powerhead rated outboards are more powerful than prop shaft rated outboards. In the mid 1980's the standard for rating an outboard's power was changed from measuring the horsepower at the powerhead to measuring it at the prop shaft where it really counts. This difference may account for a 10% or 15% increase in power, but not a 30% increase.
Bosmass	posted 11-19-2002 12:39 PM ET (US) That's it, ok so now I change my search.. I'm looking for a 'modern' 90 hp, 2 stroke.. thanks for the information.
lhg	posted 11-19-2002 03:26 PM ET (US) Yes, I agree, you want 90HP for the boat. I'd go with Mercury or Yamaha, since there is no separate oil injection tank to locate somewhere in the boat, generally a headache. The Johnson is at a disadvantage in this respect. The Merc and Yamaha make for a nice clean installation. If you want to save a little, don't rule out the Merc 75, basically a detuned 90, and a pretty strong engine. The Yamaha 70, although it looks the same as their 90, has a much smaller block. Forget the Mercury 115, as it's no faster than the Mercury 90 on a Montauk. Don't ask me why.