Vibration isolating shaft coupling & Injector cleaner when bleeding

[Dale Stone]

Hello
Looking for thoughts on shaft couplings to reduce vibration and dampen shock to the transmission when switching gears. I have a C34 MKII with a dripless and I've read the Vetus Bullflex will not fit. I'm leaning towards the R&D coupling. Does anyone have experience with it or other similar couplings?

Thanks
Dale Stone

[Jim Hardesty]

You asked for thoughts.  Here's mine, sure others will disagree.  If your cutless bearing, shaft, prop, motor mounts and alignment is good you don't need one.  Shamrock is very smooth motoring.  Towed my friend back from Detroit after his flexible coupling blew-up and damaged his transmission.

Jim

[Roc]

Dale,
I have a PYI dripless seal and a Federal Flexible coupling that fits.  Do a search on "Federal" on this site.  There have been a few discussions on this very topic.

[Ron Hill]

Dale : You already have a "damper" attachment attached to the flywheel of you M35BC engine.  It is there to dampen the changes from shifting!! Yours is no longer a "plate" like the M25/XPs engines, but it's attached to the fly wheel center and does the same job.

A few thoughts

[Dale Stone]

Thanks all for the replies.
The transmission flange to prop shaft coupling is within 0.003". I aligned it while on jacks and then again following 2 weeks in the water. Interesting that the alignment did change by a few thousands after launching. The prop shaft is new SS, (the original bronze was corroding and the surveyor noted it required changing), and the cutless is new. The dripless is new as well. I installed a 2 blade folding GORI. It is a 15X12 and calculated to be correct by GORI.

In general, I have very few concerns with the system. The engine shakes at 800RPM in neutral (typical I'm told). In forward at around 1300 RPM to 1500 RPM there is a vibration that rattles the cockpit locker covers. Inceasing the RPM does stop it. I've read that an engine on rubber mounts  tends to bounce around a bit and can stress the dripless or stuffing box and cutless.

I like the folder but expect it adds  stress to the transmission gear when shifting. So the interest in isolator couplings is to reduce the effect of the folder and cut down on the vibration around 1300 RPM to 1500 RPM.

A 15 knot breeze drives the boat over 7 knots on a beam reach. And that is with a furling main sail that is really just another jib with it's negative roach. Pretty happy with it and think the folder is a significant drag reduction that adds 0.5 kt to 1 kt to the boat speed.

New questions:
1) Ron, Do you think the flywheel damper is adequate with a folder?
2) Roc, Did you install the Federal and notice a difference?
3) Jim, Your story is concerning. Do you know the make of the isolator? Do you notice any vibration underway at a specific RPM?

Thanks
Dale

[Ron Hill]

Dale : I doubt that you have enough hours on your engine to have worn out that damper.  Get yourself a laser tach to check the engine tach for accuracy.  800rpm is low for a normal idle and should shake your teeth.  I usually only idle at 1000-1200 rpm just to smooth things out and have the alternator putting out.  A 2 bladed folder should make no difference.
With a new shaft & cutless I'm going to guess that your 1300-1500rpm vibration may be injectors.  Walmart has PS diesel Injector cleaner. I fill my Racor with pure PS and then run the engine to get a real shot of the cleaner into the injectors. See it that doesn't help.  Also run the engine (every so often) at full RPM for about 20 seconds.  That helps blow out any junk.

A few thoughts

[Jim Hardesty]

Do you know the make of the isolator? Do you notice any vibration underway at a specific RPM

Dale,
I think it was a drive saver, not sure.  I have a Maxi-prop.  The only vibration is at 800 rpm, FWIW the recommended idle is 1000 or 1200 rpm.  I have it set about 800 and don't idle it long at that low rpm.  Ron's suggestion of injector cleaner is well worth a try, my choice is Lucus.  I do it as regular maintenance.
Jim

[Dale Stone]

Thanks guys, that sounds like a great idea. I'll check out the PS and the Lucus. Never thought about cleaning the injectors like that.

[Stu Jackson]

Thanks guys, that sounds like a great idea. I'll check out the PS and the Lucus. Never thought about cleaning the injectors like that.

Hi, Dale, it's mentioned in many of the Bleeding threads, usually 'cuz it's part of the process.  I've done it for years when I first heard about it from Ron.  Better that than a slug of air or having to even begin to deal with diesel.  I use whatever I can find, always buy two and always have some on hand on board.

[Dale Stone]

Hi Stu, Jim and Ron,
I've looked for blogs about cleaning the injectors by filling up the Racor with a cleaner. Not very successful but then I'm not so skilled in searching. The cleaners of choice are PS, Lutrun and maybe SeaFoam.

My plan is:
1) Shut off ball valve to tank
2) Drain the Racor bowl
3) Unscrew plastic container and fill it with cleaner or find other path to fill the Racor bowl with cleaner
4) Open ball valve to the tank
5) Check for leaks
6) Start her up

Is it that simple?

Thanks
Dale

[John Langford]

I have been dealing with a noisy damper plate and commented on that today on a parallel thread. My only extra point on this thread would be that the Westerbeke recommended idling range for the M35B engines is 800 to 1000rpm. I would be concerned that idling in the 1300rpm range would put significant strain on the clutch when going into gear.

[Stu Jackson]

Hi Stu, Jim and Ron,
I've looked for blogs about cleaning the injectors by filling up the Racor with a cleaner. Not very successful but then I'm not so skilled in searching. The cleaners of choice are PS, Lutrun and maybe SeaFoam.

My plan is:
1) Shut off ball valve to tank
2) Drain the Racor bowl
3) Unscrew plastic container and fill it with cleaner or find other path to fill the Racor bowl with cleaner
4) Open ball valve to the tank
5) Check for leaks
6) Start her up

Is it that simple?

Thanks
Dale

Yes, it's that simple, but your #3 should be: Screw the plastic bowl underneath the new filter, fill both, screw new filter onto housing.

Covered in the Bleeding 101.

[Dale Stone]

Thanks Stu,
I am a bit concerned about the full strength injector cleaner. Though it probably mixes with diesel as it gets pump to through the fuel system. If you guys have been doing this as a regular maintenance then I shouldn't be worried.

Thanks again.

[Ron Hill]

Dale : You'll find the PS injector cleaner is oil based and it will mix with the fuel in the line and the new fuel coming from the tank.

A thought

[Dale Stone]

Thanks Ron, I am going to Walmart and getting a few bottles of the PS injector cleaner. I'll give this a try this weekend and report back.