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Author Topic:   Yamaha 70-HP Two-stroke

jimh posted 05-05-2007 02:58 PM ET (US)
The venerable 850-cc Yamaha two-stroke three-cylinder 70-HP outboard motor swept its class in the 2007 24-hour power boat race in Rouen, France.
http://www.xtrem-photo.com/24h2007/IMG_8665.jpg
Racing against the larger displacement Mercury 60-HP four-stroke and the Evinrude 90-HP E-TEC (which apparently was granted status in the class due to its "green" or low-emission nature), the old fashioned Yamaha motor finished first through sixth, and took nine of the top ten spots in their class.
Having once owned a pair of these motors, I can say I am not surprised. They must be one of the best small outboard motors ever made. They're surprisingly powerful for their displacement, and apparently very durable. Too bad they're not widely available in the U.S. anymore.
Peter posted 05-05-2007 06:44 PM ET (US)
I have one of these on my 15 Super Sport. Great, simple motor. I often feel that my 15 Super Sport looks just like that picture when the Yamaha 70 is running WOT and the Super Sport is zipping along at 42+ MPH.
jimh posted 05-05-2007 07:26 PM ET (US)
By the way, I believe that the Yamaha 70-HP 850-cc motor is just about a carbon copy of the OMC 70-HP motor. Master OMC mechanic David Zammitt told me that it was such a blatant copy that OMC sued Yamaha over it and won.
Roswell posted 05-05-2007 09:36 PM ET (US)
Peter, your comparison between a 15' and that hydroplane put a smile on my face... Please tell me you have a paint job like that, too.

jimh,
If available from your source, do you know the order of finishers of the competing outboard brands? Were they outfitted on the same, similar hull? Perhaps just the top ten in the race? Or a link to that race's results, would be great. Thanks in advance.
My father has an old (probably mid 70's) Aquasport 19' with a 2005 Yamaha 70 HP 2-Stroke on "Lake of Bays" In Ontario, Canada, great engine. Plus, a better looking hull than many offered these days, if I may say so myself.
alfa posted 05-06-2007 03:27 AM ET (US)
Jim,
In S850 class, all engines where Yamaha !
Alain
jimh posted 05-08-2007 08:30 PM ET (US)
My understanding is the Yamaha 70-HP competed in a class with Mercury and Evinrude motors. I believe this is called Class-1. I have not seen a good comprehensive listing of all results. Please point us to more information if you have it. Thanks.
jimh posted 05-08-2007 08:38 PM ET (US)
Here is a listing of results:
http://www.24heuresrouen.org/2007/resultats/resultath.php
Translated to English:
http://google.com/translate?u=http%3A%2F%2Fwww.24heuresrouen.com%2F& langpair=fr%7Cen&hl=en&ie=UTF8
jimh posted 05-08-2007 08:41 PM ET (US)
Please note that the CLASS-1 listings include boats powered by Mercury and Evinrude motors. On this basis I have concluded that the Mercury and Evinrude motors competed in the same class as the Yamaha 850-cc motor.
Mobjack posted 05-10-2007 02:45 PM ET (US)
Hey Guys,
Sorry this is slightly off topic, but how do you think a 70 2stroke yamaha would perform on a montauk? What kind of top end speed would you see, fuel economy, etc.
I have an ailing 75 hp johnson right now.
jgkmmoore posted 05-10-2007 03:18 PM ET (US)
42.
Mobjack posted 05-11-2007 09:33 AM ET (US)
Is that in knots or statute mph? that sounds high.

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Author	Topic: Yamaha 70-HP Two-stroke
jimh	posted 05-05-2007 02:58 PM ET (US) The venerable 850-cc Yamaha two-stroke three-cylinder 70-HP outboard motor swept its class in the 2007 24-hour power boat race in Rouen, France. http://www.xtrem-photo.com/24h2007/IMG_8665.jpg Racing against the larger displacement Mercury 60-HP four-stroke and the Evinrude 90-HP E-TEC (which apparently was granted status in the class due to its "green" or low-emission nature), the old fashioned Yamaha motor finished first through sixth, and took nine of the top ten spots in their class. Having once owned a pair of these motors, I can say I am not surprised. They must be one of the best small outboard motors ever made. They're surprisingly powerful for their displacement, and apparently very durable. Too bad they're not widely available in the U.S. anymore.
Peter	posted 05-05-2007 06:44 PM ET (US) I have one of these on my 15 Super Sport. Great, simple motor. I often feel that my 15 Super Sport looks just like that picture when the Yamaha 70 is running WOT and the Super Sport is zipping along at 42+ MPH.
jimh	posted 05-05-2007 07:26 PM ET (US) By the way, I believe that the Yamaha 70-HP 850-cc motor is just about a carbon copy of the OMC 70-HP motor. Master OMC mechanic David Zammitt told me that it was such a blatant copy that OMC sued Yamaha over it and won.
Roswell	posted 05-05-2007 09:36 PM ET (US) Peter, your comparison between a 15' and that hydroplane put a smile on my face... Please tell me you have a paint job like that, too. jimh, If available from your source, do you know the order of finishers of the competing outboard brands? Were they outfitted on the same, similar hull? Perhaps just the top ten in the race? Or a link to that race's results, would be great. Thanks in advance. My father has an old (probably mid 70's) Aquasport 19' with a 2005 Yamaha 70 HP 2-Stroke on "Lake of Bays" In Ontario, Canada, great engine. Plus, a better looking hull than many offered these days, if I may say so myself.
alfa	posted 05-06-2007 03:27 AM ET (US) Jim, In S850 class, all engines where Yamaha ! Alain
jimh	posted 05-08-2007 08:30 PM ET (US) My understanding is the Yamaha 70-HP competed in a class with Mercury and Evinrude motors. I believe this is called Class-1. I have not seen a good comprehensive listing of all results. Please point us to more information if you have it. Thanks.
jimh	posted 05-08-2007 08:38 PM ET (US) Here is a listing of results: http://www.24heuresrouen.org/2007/resultats/resultath.php Translated to English: http://google.com/translate?u=http%3A%2F%2Fwww.24heuresrouen.com%2F& langpair=fr%7Cen&hl=en&ie=UTF8
jimh	posted 05-08-2007 08:41 PM ET (US) Please note that the CLASS-1 listings include boats powered by Mercury and Evinrude motors. On this basis I have concluded that the Mercury and Evinrude motors competed in the same class as the Yamaha 850-cc motor.
Mobjack	posted 05-10-2007 02:45 PM ET (US) Hey Guys, Sorry this is slightly off topic, but how do you think a 70 2stroke yamaha would perform on a montauk? What kind of top end speed would you see, fuel economy, etc. I have an ailing 75 hp johnson right now.
jgkmmoore	posted 05-10-2007 03:18 PM ET (US) 42.
Mobjack	posted 05-11-2007 09:33 AM ET (US) Is that in knots or statute mph? that sounds high.