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Old 07 May 2016, 19:59   #1
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contra rotating outboard

I'm currently in the process of buying a osprey eagle with a Yamaha 130 v4 2 stroke everything on the outboard seems good but its a contra rotating unit .I was under the impression that was only used if 2 outboards were in use one would spin the other way to eliminate any pulling to one side .will I have any problems using a contra rotating unit on its own
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Old 07 May 2016, 20:11   #2
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Shouldn't be a problem - so long as you never fit a normal rotation prop on it! (as someone on here did)

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Old 08 May 2016, 04:59   #3
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Quote:
Originally Posted by beerbelly View Post
I'm currently in the process of buying a osprey eagle with a Yamaha 130 v4 2 stroke everything on the outboard seems good but its a contra rotating unit .I was under the impression that was only used if 2 outboards were in use one would spin the other way to eliminate any pulling to one side .will I have any problems using a contra rotating unit on its own
As willk say shouldn't be an issue BUT If the boat was originally rigged for a standard rotation engine, the engine may have been offset on the transom to compensate for the prop torque. If it's had a left hander fitted since, you might have issues with it pulling over to the starboard side, take it for a test run first.
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Old 08 May 2016, 05:41   #4
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Which side is the elephants trunk on, that should tell you if it was originally built for a std rotation.

If the trunk is on the Starboard side when you look from the back of the boat then it would have original been a std rotation engine fitted.

If this is the case you might need to be careful as the trunk could get caught in the prop if its long enough.
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Old 08 May 2016, 08:47   #5
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thanks it has two trunks but my sr4 has a standard rotation outboard and the trunk is on the port side and never had a problem with it getting in the way .as for offset yes the guy who is selling it said it had been offset to counteract prop torque
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Old 08 May 2016, 14:44   #6
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the guy who is selling it said it had been offset to counteract prop torque
check the engine is offset to Port (ie its about 20-30mm further to the left hand side of the transom when looked at from behind.) If so this is correct.

If not then its not the end of the world as the engine can be moved. Just needs to be done properly with the transom holes being doweled and filled etc.
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Old 08 May 2016, 14:59   #7
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thanks I will take a tape and check it
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Old 08 May 2016, 22:36   #8
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Props may be harder to come by. Selection for LH props can be limited.

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Old 09 May 2016, 10:44   #9
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Props may be harder to come by. Selection for LH props can be limited.

jky

+1 also LH props tend to come in larger pitches as contra rotating engines are usually rigged as twins


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Old 09 May 2016, 11:23   #10
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Quote:
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Which side is the elephants trunk on, that should tell you if it was originally built for a std rotation.

If the trunk is on the Starboard side when you look from the back of the boat then it would have original been a std rotation engine fitted.

If this is the case you might need to be careful as the trunk could get caught in the prop if its long enough.
Don't get that at all. what does it matter what side trunk is as to what gearbox is fitted and it getting caught in prop . Can you explain more please
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