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Old 18 May 2011, 06:50   #1
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Any Ideas?

One of my Dryt Stack customers has recently re-engined their Avon 620 (the hull with the fins that poke down) and have changed from a Yamaha 115 to a "counter rotating" Suzuki 150 (don't ask!!!). They now say that they are experiencing a definite "tilt" to the Rib when under power. They have altered the angle of the fin on the cavitation plate, but to no effect. They have tried putting ballast to one side of the boat, but this needs at least 100kg to correct and will play havoc with the fuel consumption. He's considering moving the engine but only has about an inch and a half on the transome to play with. He's also been considering trim tabs. So, before he embarks on any wild and expensive fixes; what do you guys think? I'm sure it's been discussed before, but any new ideas would be welcome.
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Old 18 May 2011, 07:01   #2
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Offset.
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Old 18 May 2011, 07:12   #3
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Quote:
Originally Posted by Mollers View Post
Offset.
or in his case Onset!
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Old 18 May 2011, 07:46   #4
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how about a normal rotating Yamaha 115 ?

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Old 18 May 2011, 07:50   #5
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Seriously, I think he's going to have to move that engine, the one and a half inches may be enough, either that or find a conventional rotating Suzuki gearbox, but you did mention expensive!
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Old 18 May 2011, 07:53   #6
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Quote:
Originally Posted by Starovich View Post
how about a normal rotating Yamaha 115 ?

I think he was quite happy with the Yam 115, but unfortunately despite claims of military quality security someone stole it from his boat while it was at a nearby "rival" dry stack (not mentioning any names)!!! Still, at least they didn't take the whole Rib.
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Old 18 May 2011, 08:00   #7
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I'd agree that moving the engine is probably the way to go.
Probably a inch will do.

Changing the gearbox may be a very expensive way to move the tilt the other way.


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Old 18 May 2011, 08:51   #8
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Thanks for the comments. I think we'll go with an engine move as it's relatively easy. If it works, I'll let you all know.
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Old 18 May 2011, 09:05   #9
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How about different prop, that also might change something, test 4 blade or otherwise differrent?
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Old 18 May 2011, 10:27   #10
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Ask Hightower, he's more up on this sort of thing
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