Bad Vibrations

Tom · 2012-03-12 05:29:57

Brand new member to Association/Forum. Look forward to helpful info.
Purchased Aries last year. Unable to perform sea trial before purchase. Encounter terrible vibration when RPMs increased when underway. Atomic 4 engine, folding prop, wheel steering.
Tom Ellis
Aries ‘76 C&C 27
The Blue Mountains, ON

carriden · 2012-03-12 06:26:37

Hey Tom, welcome to the fraternity. With a folding prop, vibration often occurs when one of the blades is reluctant to unfold, assuming that the blades are not geared to each other. If Aries is out of the water then check that both blades are moving freely. This sort of vibration sometimes happens with Carriden's Martec folding prop and the solution is to throttle down to idle, put the gearbox into reverse and then kick the throttle up. This usually works in getting both blades to unfold and then I can return to forward gear. Other potential sources of vibration can be a bent propeller shaft or a worn-out cutless bearing, which would allow the shaft to vibrate as it turns. There may be issues in the engine that could cause such a vibration, perhaps a snapped connecting rod or some such, but I have never heard any Atomic IV owner complain of encountering such a problem. It is almost invariably the prop or the prop shaft, or possibly a shaft alignment issue.
Best of luck,
Marcus from Carriden

Mk III, Hull #847
Oakville, Ontario

davidww1 · 2012-03-12 06:50:39

Loose bolts and/or nuts on the engine bed or shaft coupling will magnify any alignment issues. Since the boat is new to you, you'll do well to check alignment after the boat has been back in the water for a week then reef all nuts and bolts really, really tight.

David Weatherston
Towser, Toronto
C&C 27 Mk IV

Tom · 2012-03-12 10:14:01

Hi Marcus. Thanks for the welcome and the suggestions. Aries is lying on the hard at the Collingwood Yacht Club. I hope to identify/solve the problem before she is lifted in. I will check the propeller shaft first to see if it is true. The vibration is minimal at low RPMs so I am hoping that it is not a prop problem. I have checked both blades and they open and move freely. I will remember your suggestion re throttling down to idle, into reverse then throttling up. Some of my club members have offered to help so I will have the cutlass bearing checked too.
It is terrific to have Association members who have practical suggestions.
Tom Ellis
Aries ‘76 C&C 27
The Blue Mountains, ON

Tom · 2012-03-12 10:15:54

David. Thanks for the suggestions and your assistance with registration.
Tom Ellis
Aries ‘76 C&C 27
The Blue Mountains, ON

Jeff · 2012-03-22 02:34:50

I had the same issues last season after putting mine in the water. Ended up being that the home made shaft coupler became out of alignment. I would think that easiest start to diagnose the problem is to sit in your cockpit locker and look at the shaft/engine while someone turns it from outside. If everything is staying nice and true then your prop probably isn't opening properly. If the engine moves around a bunch then I would disconnect the shaft from the engine and have the shaft turned again. If the shaft turns true spin your coupler while watching the engine. If it doesn't move around while turning the coupler you most likely have an alignment problem. Good luck.C&C 27 Mk I #4
Clockwork
Port Stanley, On.

Tom · 2012-03-23 02:43:40

Jeff, thanks for your helpful suggestions. I will begin problem diagnosis next week weather permitting.
I plan to replace the in-mast wiring and install a chartplotter as well. This is my second season with Aries and I look forward to sailing to the north channel of Georgian Bay this summer.
When will you launch Clockwork this season?
Tom Ellis
Aries ‘76 C&C 27
The Blue Mountains, ON

Jeff · 2012-03-26 03:59:47

We launch on the first weekend in May, so I still have a couple weeks to paint the bottom, compound and wax, re-wire the mast, possibly insulate the icebox, install my max-prop and generally claen the joint up. Good luck with getting yours sorted out, hopefully it is just an out of alignment issue. Would probably be the least boat bucks.C&C 27 Mk I #4
Clockwork
Port Stanley, On.

Tom · 2012-03-27 01:33:22

We launch on May 6. Time to do repairs and prep for the season. I will check for allignment issues as you suggested. Thanks again.
Tom Ellis
Aries ‘76 C&C 27
The Blue Mountains, ON

C&C 27 Association Forum

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#1 2012-03-12 05:29:57

Bad Vibrations

#2 2012-03-12 06:26:37

Re: Bad Vibrations

#3 2012-03-12 06:50:39

Re: Bad Vibrations

#4 2012-03-12 10:14:01

Re: Bad Vibrations

#5 2012-03-12 10:15:54

Re: Bad Vibrations

#6 2012-03-22 02:34:50

Re: Bad Vibrations

#7 2012-03-23 02:43:40

Re: Bad Vibrations

#8 2012-03-26 03:59:47

Re: Bad Vibrations

#9 2012-03-27 01:33:22

Re: Bad Vibrations

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