Merc Racing 200 hp duo prop outboard. Not new but... WTF???
11-01-2011, 07:43 PM
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Merc Racing 200 hp duo prop outboard. Not new but... WTF???
Thought I'd seen most merc racing motors from the late 80's and upl. Does anyone have any info on this thing? Did they work, or was it just a prototype deal.
Only duo prop OB I've ever seen, was the Yamaha 150 duo prop.
Oh, and it looks like they where two speed!?
Only duo prop OB I've ever seen, was the Yamaha 150 duo prop.
Oh, and it looks like they where two speed!?
Last edited by A.O. Razor; 11-01-2011 at 07:50 PM.
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11-02-2011, 04:04 PM
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Well dug up a little info here and there during lunch
It's not a BH lower. It is infact a two speed, not in the normal sense, but in the sense that one high pitch prop is free wheeling while the low pitch prop accelerates the boat and runs at lower speeds. Then at a set rpm, a clutch of some kind shifts to the other prop with high pitch, thus making the low pitch prop free wheel. That is some bad azz engineering in a small gearcase like that.
Imagine the prop pitch discussions we would have in the prop forum, if this where the norm
Many times we can't even agree on one
It's not a BH lower. It is infact a two speed, not in the normal sense, but in the sense that one high pitch prop is free wheeling while the low pitch prop accelerates the boat and runs at lower speeds. Then at a set rpm, a clutch of some kind shifts to the other prop with high pitch, thus making the low pitch prop free wheel. That is some bad azz engineering in a small gearcase like that.
Imagine the prop pitch discussions we would have in the prop forum, if this where the norm
Many times we can't even agree on one
Last edited by A.O. Razor; 11-02-2011 at 04:10 PM.
11-02-2011, 05:03 PM
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Well dug up a little info here and there during lunch
It's not a BH lower. It is infact a two speed, not in the normal sense, but in the sense that one high pitch prop is free wheeling while the low pitch prop accelerates the boat and runs at lower speeds. Then at a set rpm, a clutch of some kind shifts to the other prop with high pitch, thus making the low pitch prop free wheel. That is some bad azz engineering in a small gearcase like that.
It's not a BH lower. It is infact a two speed, not in the normal sense, but in the sense that one high pitch prop is free wheeling while the low pitch prop accelerates the boat and runs at lower speeds. Then at a set rpm, a clutch of some kind shifts to the other prop with high pitch, thus making the low pitch prop free wheel. That is some bad azz engineering in a small gearcase like that.
Last edited by bobbowobbo; 11-02-2011 at 05:06 PM. Reason: late spell check
11-02-2011, 05:19 PM
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11-02-2011, 05:33 PM
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the two speed part of it makes sense to me. There was some success using mis matched props on the Volvo DPX's but at the cost of decreased lower unit life. I would guess having an over or under drive available to one of the props would eliminate this but still allow optimum pitch. Also i have been told (by C Spray actually ) that as a dual prop reaches higher speeds approaching 90? 100? the second prop becomes a drag. I wonder if allowing one of the props to freewheel, as in this case, eliminates or lessens the condition? Cool azz outboard btw 
wonder where its at
) that as a dual prop reaches higher speeds approaching 90? 100? the second prop becomes a drag. I wonder if allowing one of the props to freewheel, as in this case, eliminates or lessens the condition? Cool azz outboard btw wonder where its at
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Throttles- Cleveland Construction 377 Talon
08 OPA Class 1 National Champion
08 Class 1 Geico Triple Crown Champion
08 OPA High Points Champion
10 OPA Class 1 National Champion ( happy now Ed! )
