Cruisers Forum
 


Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 01-12-2018, 06:19   #121
Registered User

Join Date: Sep 2013
Location: Windham NH
Boat: Bristol 29.9 1978
Posts: 105
Re: Yanmar SB12 Using Oil

Compass - [B]I'd [B]like to know if the engine is OK, but in reality I won't know how it is really doing until it's been run for ten hours or so. So, I won't learn anything by running it now other than that it seems to be properly reassembled. (If it won't run, I'm not going to try and diagnose the issue until spring.) I'll just feel a lot better when I button up the boat for winter that the motor is in running condition.

I sure do appreciate all the help you and Wotname and some others have provided. You've give me confidence to move ahead when I got into areas I was not fully versed in.
Homer Shannon is offline   Reply With Quote
Old 14-12-2018, 12:26   #122
Registered User

Join Date: Sep 2013
Location: Windham NH
Boat: Bristol 29.9 1978
Posts: 105
Re: Yanmar SB12 Using Oil - IT RUNS

I received all the parts I needed to finish the conversion to an off-motor filter a week ago but it was too cold to bleed the fuel and try to start the motor. Finally today it got to about 40 degrees and that was good enough.

I finished assembling the fuel system and bled it. Then I gave the engine a test run. The motor started pretty quickly, though not instantly, and runs nicely. I didn't run it long or hard as it has no cooling water connected to it and the 30 weight oil is going to be pretty thick at this temperature. But, it ran nicely and idled much smoother than in the past - for what that's worth.

The only remaining mystery is the diesel return line coming off of the fuel injector. I expected this to expel a stead, if small, dribble of fuel. No fuel seemed to come out of it at all. Perhaps the engine has to run longer or harder for this to start to run?

Completing this, I finished snugging up the winter tarp and put the ladder away. I'm done 'til spring. Oh, I left the piston at TDC
Homer Shannon is offline   Reply With Quote
Old 15-12-2018, 14:57   #123
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 11,451
Re: Yanmar SB12 Using Oil

Congratulations on getting it back together and running. Let's hope your original problem has been fixed.

I'm looking forward to an update next spring / summer after you have run it for awhile.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Old 18-12-2018, 15:27   #124
Marine Service Provider

Join Date: Sep 2014
Location: Auckland, NZ
Boat: Compass 790 , 7.9 metres or 26 ft
Posts: 1,736
Re: Yanmar SB12 Using Oil

don't know if I'd expect an instant start in that temp especially with unbedded rings. I'm no injection pump expert having only done up 1 but when ours wasnt going too well it wouldnt flow anything from rtn line either. Injection shop said pump was worn out but I didnt trust that shop ( long story) altho having said that I know it had water thru it so it's likely that was true. After i put new plunger & barrel with a delivery valve in injection pump it did flow fuel thru rtn line. However you havent run yours for long so i wouldnt panic yet.
Maybe someone who actually works on injection pumps will chime in.
Glad the project sounds like an upgrade success so far.
Compass790 is offline   Reply With Quote
Old 18-12-2018, 18:20   #125
Registered User

Join Date: Sep 2013
Location: Windham NH
Boat: Bristol 29.9 1978
Posts: 105
Re: Yanmar SB12 Using Oil

I didn't expect it to start quickly either and actually just hoped it would "kick", showing some intent to start some day, probably later in the spring when it was warm. However, with some cranking it did start and ran well. As for the return fuel line, I found some indications online that the Yanmars don't actually return much to the tank. So little in fact, in some cases it did not seem to return any. I think I'm in that group but I'll find out more when I run it hard next season.
Homer Shannon is offline   Reply With Quote
Old 29-04-2019, 17:47   #126
Registered User

Join Date: Sep 2013
Location: Windham NH
Boat: Bristol 29.9 1978
Posts: 105
Re: Yanmar SB12 Using Oil

Well, the cover is off - just a bit late this year - and I ran the motor for a while. It started fairly easily and ran well with little smoke or other issues. My only concern is a significant amount of oil I found floating in the bilge when I checked things before starting. I'd estimate there was a cup to a pint of oil floating. There is no evidence of leaking anywhere on the motor, but if it has been weeping out of the oil pan gasket until it reached the gasket level, this would all have dripped away long ago. The level on the dipstick looks about right to at the gasket line. I didn't fill the oil all the way last fall, so I don't have a good way to know how much really leaked out.

I guess I'll have to fill the oil up and put some cardboard under the motor to try and see where it is leaking from. I noted last fall that the oil pan holds two quarts. Normally a top-up takes four quarts. I assume this means that the gasket is normally "underwater" and will leak profusely if there is a problem with the gasket. Something else to figure out.

My other main problem to solve before launch (in addition to normal items) will be to square away the prop shaft cutlass bearing. The old bearing was heavily corroded, probably because it is not bonded to the rest of the boat. I have a new one that is made out a fiber material instead of bronze. There is no way that the three dinky and pretty stripped set screws in the prop shaft tube are going to hold this thing. I'm thinking about some new set screws, set further forward where there is more material. If I drill the cutlass bearing a bit, I can run the set screws through the bearing all the way to the shaft and then back them out a bit so that they remain in the bearing but not touching the shaft. Any suggestions on this?
Homer Shannon is offline   Reply With Quote
Old 30-04-2019, 12:56   #127
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,304
Re: Yanmar SB12 Using Oil

Cutlass bearing is supposed to be a press fit.
Mine is looser than it should be, so I “spot” mine, that means remove the set screw and mark center of bearing with an automatic center punch, then drill a small pilot hole not all the way through the metal, then drill with as large a bit as is possible without hitting the threads in the tube, then install set screws and lock with blue loctite.
a64pilot is offline   Reply With Quote
Old 30-04-2019, 13:19   #128
Registered User
 
daletournier's Avatar

Join Date: Jan 2012
Location: Seychelles
Boat: Catalina 470
Posts: 4,618
Re: Yanmar SB12 Using Oil

You can also use some epoxy to hold it in place. Only smear it on half the bearing. It can removed down the track using a heat gun.
daletournier is online now   Reply With Quote
Old 30-04-2019, 19:26   #129
Marine Service Provider

Join Date: Sep 2014
Location: Auckland, NZ
Boat: Compass 790 , 7.9 metres or 26 ft
Posts: 1,736
Re: Yanmar SB12 Using Oil

Hope my tip about using silicone on yr sump gasket isn't the cause of your oil leak! I've used it for decades so am practiced with it & dont have problems but it's possible I guess. Keep us posted what you find & how engine is after you take it for a long run.
Compass790 is offline   Reply With Quote
Old 01-05-2019, 18:53   #130
Registered User

Join Date: Sep 2013
Location: Windham NH
Boat: Bristol 29.9 1978
Posts: 105
Re: Yanmar SB12 Using Oil

Thanks, guys. I'll get out and start working to figure out the details as soon as the rain stops.

On the cutlass bearing, I'm thinking that if I pull the prop shaft out again, which won't be hard - I still have good access to it, I can wax the bearing and then inject some epoxy to fill up the very loose fitting in the prop shaft extrusion. It will be a finagle, but I think I can make it right.

Compass 790, I DO suspect that the silicone gasket is my problem, but no worries about blame. I took your advice and maybe it didn't work right for me. Should have held off a waited for a gasket to come in... if that is the issue. I'll add a pint of oil and see where it starts coming out from. It is quite possible that this is just a very small leak; after all, it has had five months to leak out. If it's super minor, I'll just build a small pan to go under the motor. But, I think putting in a new gasket is probably the right fix.
Homer Shannon is offline   Reply With Quote
Old 02-05-2019, 15:15   #131
Marine Service Provider

Join Date: Sep 2014
Location: Auckland, NZ
Boat: Compass 790 , 7.9 metres or 26 ft
Posts: 1,736
Re: Yanmar SB12 Using Oil

Compass 790, I DO suspect that the silicone gasket is my problem, but no worries about blame. I took your advice and maybe it didn't work right for me. Should have held off a waited for a gasket to come in... if that is the issue. I'll add a pint of oil and see where it starts coming out from. It is quite possible that this is just a very small leak; after all, it has had five months to leak out. If it's super minor, I'll just build a small pan to go under the motor. But, I think putting in a new gasket is probably the right fix.[/QUOTE]

Yes I'm feeling guilty now! but not panicking yet as maybe a little nip up may fix the leak if it is in the silicone seal. I await the verdict, hopefully i'll be exonerated.
Compass790 is offline   Reply With Quote
Old 03-05-2019, 06:40   #132
Registered User

Join Date: Sep 2013
Location: Windham NH
Boat: Bristol 29.9 1978
Posts: 105
Re: Yanmar SB12 Using Oil

The rain has stopped a bit, so I took a minute to go work on the oil leak part of my issues. I placed a piece of cardboard covered with a couple of layers of cut toweling under the motor and added about 1-1/2 cups of oil, which brought the level up to the top of the hashmarks on the dipstick, which is well above the block/oil pan gasket. No immediate problems.

I'll give this until this afternoon and then go and have a look at it again. Will I be surprised if there is no evidence of leaking at all? Not a bit. There are already plenty of mysteries in this old motor!
Homer Shannon is offline   Reply With Quote
Old 04-05-2019, 06:16   #133
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 11,451
Re: Yanmar SB12 Using Oil

Homer, do be aware that a single cylinder engine gives the crankcase a pulsating pressure effect when it is running which effectively puts some pressure on the oil in the crankcase. Due of course to the piston moving up and down in a semi sealed crankcase.

This MIGHT be causing the oil to be pushed out of the slightly failed silicone gasket.

Multi cylinder engines don't suffer from this (unless there is a lot of blow by).
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Old 05-05-2019, 10:21   #134
Registered User

Join Date: Sep 2013
Location: Windham NH
Boat: Bristol 29.9 1978
Posts: 105
Compass790 - Total Exoneration!

I topped up the oil and placed a rag under the motor over two days ago. Today I checked the motor and there is no sign of dripping and the oil is still at the full mark. This totally exonerates Compass790 - the silicone oil pan gasket is NOT the culprit for my mystery bilge oil.

Of course, I still don't know the source of the bilge oil. I can only guess that it came from various and sundry sources as the water got into the bilge over the winter. At this point I'm confident I don't have a major issue and I'll delegate the problem to a watch status.

I started and ran the motor again today. It fired up on about the second revolution and ran well immediately. The new, in line fuel filter still is only half full, but it does not seem to create any kind of air bubble issues. I searched several forums regarding this concern and the general consensus is that these filters normally have some air in them and it is not an issue.

So, it's time to get on with other preparations for launching. I'm calling the hauler Monday to set a date in early June.
Homer Shannon is offline   Reply With Quote
Old 06-05-2019, 18:23   #135
Marine Service Provider

Join Date: Sep 2014
Location: Auckland, NZ
Boat: Compass 790 , 7.9 metres or 26 ft
Posts: 1,736
Re: Compass790 - Total Exoneration!

Whew! I'm breathing a little easier now but still a little nervous ( see Wotname post #133 for anxiety increase theory )
Anyway hope you post again after a long run when you've splashed as you need to put under load to be sure.
Was oil in bilge same colour as oil in engine? I assume engine oil would be clean.
Compass790 is offline   Reply With Quote
Reply

Tags
oil, yanmar

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Yanmar SB12 Burning Oil! pmagistro Engines and Propulsion Systems 15 03-02-2018 17:18
Another Go on the Yanmar SB12 RW Sailor Engines and Propulsion Systems 8 09-07-2013 07:26
For Sale: Used Yanmar SB12 weststar Classifieds Archive 8 26-05-2011 06:57
Yanmar SB12 Service Manual Needed midiaxbill Monohull Sailboats 2 01-01-2011 07:46
Yanmar 1978 SB12 Winterizing Inamist Engines and Propulsion Systems 3 14-10-2010 10:16

Advertise Here


All times are GMT -7. The time now is 01:19.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.