Slipping Yanmar SD50 Cone Clutch

[colemj]

Originally Posted by arsenelupiga

I see not much issue relapping/changing even every 100 hrs

That certainly would not be acceptable to me, but to each his own.

Mark

[arsenelupiga]

my cone cluch story got a twist. I assumed any problems to do with engagement is to do with cone clutch. All that noise on internet made me not do proper research.

Now, as I am looking at issue in more detail and doing testing, realised that issue in my case is not (only) cone clutch.

What is happening is that folding propeller sometimes does not fully open! Blades are at around 45 degrees and there is almost no push forward. Propeller rotates, for sure even very fast but not fully open.

I have checked and propeller folds/unfolds smoothly by hand.

Sequence - 2000 RPM as blip to unfold propeller fully, then back to 1200 works fine. Adding RPM fast at this point makes prop not expand fully and I assumed is cone clutch. Maybe adding RPM's slowly will get better results.

L400 is good in this respect as one can easy observe propeller in action.

So, back to drawing board.

[dweist]

Thank you all for your advice regarding the slipping cone clutch on a Yanmar SD 50 Saildrive. My local Yanmar dealer in Kemah, Tx has a bad experience with lapping the cone clutch, and doesn't do it anymore. My SD50 started slipping intermittently a couple months ago and progressively got worse.

My SD50 was manufactured in 2013-14 timeframe and had 220 hours total on it when the forward gear completely failed. I could still reverse fine. This was a gradual failure as described in many comments from many owners.

Here is my situation: I went to get replacement parts for the SD50 and the Yanmar dealer told me that Yanmar has ceased production on the SD50 and its parts. So, I had to bite the bullet and replace the Yanmar SD50 with an SD60. This required the entire upper and lower unit of the SD60, as well as a conversion kit and some other part to soften the engagement of the clutch. It required multiple mechanics to lift the engine as well to install the parts. All in all, my 2014 Beneteau Oceanis 41 was out of the water for a week. After the Saildrive was replaced, I had to pay the yard to epoxy and paint the lower unit with bottom paint. Total bill was about $12,000.00!

My Yanmar dealer says the rest of my SD50 Saildrive is in great shape, with only 220 hours on it. He suggested I put it on consignment and sell it.

Anyone need an SD50? I suppose you could recondition the clutch as suggested by others, or put in the parts suggested and make this thing work. It would be useful if you need other parts as the rest of the unit is in great shape.

If your interested in this SD50 Saildrive, please contact me at my email address:

dweist@me.com

and we can talk terms, as these are no longer available from Yanmar.

Fair Winds!

dweist.

[boatbod]

Lapping the cones on the SD50 is pretty easy. We had a customer with a Lagoon that had a pair of them. Did it every year and I recall it only took 3-4 hrs or so.

[sgtPluck]

Originally Posted by arsenelupiga

my cone cluch story got a twist. I assumed any problems to do with engagement is to do with cone clutch. All that noise on internet made me not do proper research.

Now, as I am looking at issue in more detail and doing testing, realised that issue in my case is not (only) cone clutch.

What is happening is that folding propeller sometimes does not fully open! Blades are at around 45 degrees and there is almost no push forward. Propeller rotates, for sure even very fast but not fully open.

I have checked and propeller folds/unfolds smoothly by hand.

Sequence - 2000 RPM as blip to unfold propeller fully, then back to 1200 works fine. Adding RPM fast at this point makes prop not expand fully and I assumed is cone clutch. Maybe adding RPM's slowly will get better results.

L400 is good in this respect as one can easy observe propeller in action.

So, back to drawing board.

I know this is five years too late, but I think I may have the same issue (on the same boat - L400!) And was wondering if you (or anyone) found a solution, other than just blipping the throttle to get it expanded? And how did you verify the issue? I'm thinking I just need to borrow a gopro on a stick from someone to check it out - not sure I'd have many volunteers to lend me their GoPro for that purpose!