Dave,
If your shift linkage is correctly adjusted and you have dealt with the
alignment, shaft and prop, and the vibration can be described as violent as the
Revs increase, I would not rule out the transmission, despite the rebuild.
You mention a new cone gear, (?) but that does not confirm that the mating
surfaces of the bronze cone (male) and its stainless (female) mate in the
forward gear have been renewed or deglazed (lapped) when the unit was serviced.
That's where the slipping occurs. Might not hurt to check this with the shop.
It's a really weird problem, and seems like something badly out of balance
more than slipping. Mine really shook the boat. The symptoms you describe in
your first paragraph were EXACTLY what I experienced.
Good luck!
Dave
Message: 1
Date: Thu, 27 Oct 2016 01:21:07 +0000 (UTC)
From: [email protected]
To: [email protected]
Subject: Re: Stus-List Folding Prop won't open
Message-ID:
<[email protected]>
Content-Type: text/plain; charset="utf-8"
Kevin,
I've struggled with the same issue for three seasons.
When I first got the boat it have a Martek 2 blade folding prop. When motoring
off the mooring no problem. But after sailing the prop vibrated horribly.
Throwing it into reverse and then back into forward usually but not always
resolved the issue. At the end of the season I sent the prop to Martek to have
it rebuilt. I also had the transmission rebuilt and the cone gear replaced. Put
the boat back in the water in the spring and found that the problem was still
there. The following winter I replaced the Martek prop with a Flexofold. Lwo
and behold the problem is still there.
I made sure that the engine was in alignment and had two boat yard mechanics
out on the boat. When heading into a 3 knot current there was no vibration but
when we went perpendicular to the current the vibration resumed. This happened
repeatedly. The mechanics told be that the vibration is typical for a two
bladed folding prop. One thing that became apparrent during that test was that
the maximum rotation I was able to get up to was 2600 RPM. The boat has the
original Yanmar 3GM30 and Kanzaki KM3-A transmission. The gear ratio is not
stamped on the transmission but, I've been assured that the gear ratio is
2.61:1 and have no reason to believe it's not. I purchased the prop recommended
to me by Flexofold which is 2 blade 16x12R. When I told Flexofold about the
issue they insisted that the prop was the correct one and I do know that other
35 MK3s have had success with this same set up.
The Flexofold blades are geared to one another. So, it's impossible for one
blade to open while the other is not. So, that can not be the problem.
So, any ideas beyond what I've already done are greatly appreciated.
Dave J
Saltaire
C&C 35MK3
Bristol, RI
Sent from my iPad
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