Slow turning Yanmar ysm12 on 1978 Hunter 30.

[Woodrowbr]

Hello, I’m a new to sailboats and purchased my first, a 1978 Hunter 30. I bought the sailboat for a very low price knowing full well that the onboard diesel wasn’t working. The Yanmar ysm 12 engine turns over slowly and doesn’t fire up. Additionally, when you turn the key to on position an alarm buzzer from the control panel/ignition panel starts making a continuous noise that doesn’t stop. I read somewhere that there could be several issues why The engine doesn’t start up. On a forum I can’t seem to find anymore someone suggested replacing that control/instrument/starter panel as it might have gone bad. I can’t seem to find one. Does anyone have any suggestions on how to find one? Also, I would love suggestions on what other issues I need to look for that might be causing the slow turning and the continuous beep. I have already installed a brand new outboard (way cheaper than new onboard or taking old one into shop) which works fine, but I would like to make every effort to keep the old Yanmar running. Any help would be appreciated.

 

[dLj]

I believe in the 1978 hunter 30's they put ysb 30's, not the ysm. If memory serves me the only difference is the ysb is a horizontal engine and the ysm is vertical. Otherwise as far as I know they are the same engine. At least that's what I've seemed to have gleamed from my 1977.

I think there are two alarms on that engine, low oil pressure and high temperature, but I'd have to look in the manual to be sure. Your alarm problem may be as simple as the oil pressure hasn't come up or that you have a faulty system in some way. If the engine isn't starting, you won't get oil pressure.

Slow turning engine may be electrical. Have you turned the engine by hand and does it spin freely? Should spin easily until hitting compression. If you've got compression...

If you can't find the manual for this engine online send me a note, I'll send you my copy.

dj

 

[kloudie1]

As dLj says, the low oil pressure alarm will sound until the oil pressure builds, usually when the engine starts.. You may have a few problems but the slow turning is a sign of a bad battery or bad connections in the large wire start circuit or a bad solenoid contact or a bad starter.. Once you have the engine spinning, then you can troubleshoot the "no start" issue.. The little Yanmar has a compression release, so you may be able to get it spinning by decompressing and hitting the starter then re-compressing with the fuel turned on.. Remember that you can flod the engine with water by cranking a bunch with the raw water pump pumping.. best to close the seacock and remove the inlet water hose from the pump before doing much cranking/troubleshooting.
Welcome to the forum !! Good luck

 

[Woodrowbr]

I believe in the 1978 hunter 30's they put ysb 30's, not the ysm. If memory serves me the only difference is the ysb is a horizontal engine and the ysm is vertical. Otherwise as far as I know they are the same engine. At least that's what I've seemed to have gleamed from my 1977.

I think there are two alarms on that engine, low oil pressure and high temperature, but I'd have to look in the manual to be sure. Your alarm problem may be as simple as the oil pressure hasn't come up or that you have a faulty system in some way. If the engine isn't starting, you won't get oil pressure.

Slow turning engine may be electrical. Have you sound the engine by hand and does it soon freely? Should spin easily until hitting compression. If you've got compression...

If you can't find the manual for this engine online send me a note, I'll send you my copy.

dj

I think you right, its the YSB horizontal engine. Haven’t tried by Hand. I’ll try this and update on the results.

 

[Woodrowbr]

As dLj says, the low oil pressure alarm will sound until the oil pressure builds, usually when the engine starts.. You may have a few problems but the slow turning is a sign of a bad battery or bad connections in the large wire start circuit or a bad solenoid contact or a bad starter.. Once you have the engine spinning, then you can troubleshoot the "no start" issue.. The little Yanmar has a compression release, so you may be able to get it spinning by decompressing and hitting the starter then re-compressing with the fuel turned on.. Remember that you can flod the engine with water by cranking a bunch with the raw water pump pumping.. best to close the seacock and remove the inlet water hose from the pump before doing much cranking/troubleshooting.
Welcome to the forum !! Good luck

thanks for the advice. Definitely give it a try once I find the compression release.

 

[ggrizzard]

Guys, it may be a YSB 12, but the YSM 12 was horizontal as well. I had one on my 1979 H30C, but it was raw water cooled and gave up after 20 years and one rebuild. It was less than optimal for the H30C series and I replaced it with a 2GM20F. Solved two problems with that upgrade.

Your panel may not be a problem. Bad battery or electrical connection, as kloudie1 suggests,
is more likely. However, no one I know of or heard from ever started a YSM or YSB with the crank.
I always hoped it would work, so maybe you'll have the magic touch.

 

[dLj]

I think you'd have to stand on the side of the engine to actually start one of these engines by hand cranking. So you'd have to have the motor out of the boat. I don't see any other way on these engines.

I tried hand cranking mine to start it but couldn't. My old Volvo was relatively easy to hand crank start, but not with the setup on the Yanmar.

dj

 

[Benny17441]

1) Check the batteries, make sure they are fully charged and healthy, 2) check the wires and connectors, make sure they are clean and tight. 3) Check the viscosity of the oil, there is a tradeoff, too thin helps cranking speed but not compression and viceversa 4) Bench test the starter. 5) check the valves lash. Yanmar engines burn fuel by heating it to its flash point by compressing it. Yanmars build compression by fast consecutive revolutions. If the cranking speed cannot keep up and produce more compression than what is lost in the exhaust stroke the engine will not fire. If the engine is well worn and has low compression then it could benefit from using a heavier oil. The starter draws a lot of power and if the engine does not start, repeated tries will quickly weaken the battery. When cranking go ahead and open the throttle to 3/4 and be ready to drop back to idle as soon as the engine fires.

 

[Dalliance]

Hello, I’m a new to sailboats and purchased my first, a 1978 Hunter 30. I bought the sailboat for a very low price knowing full well that the onboard diesel wasn’t working. The Yanmar ysb 12 engine turns over slowly and doesn’t fire up. Additionally, when you turn the key to on position an alarm buzzer from the control panel/ignition panel starts making a continuous noise that doesn’t stop. I read somewhere that there could be several issues why The engine doesn’t start up. On a forum I can’t seem to find anymore someone suggested replacing that control/instrument/starter panel as it might have gone bad. I can’t seem to find one. Does anyone have any suggestions on how to find one? Also, I would love suggestions on what other issues I need to look for that might be causing the slow turning and the continuous beep. I have already installed a brand new outboard (way cheaper than new onboard or taking old one into shop) which works fine, but I would like to make every effort to keep the old Yanmar running. Any help would be appreciated.

I have an ‘82 H30 with the 2GM engine, but I think the control panel is the same. When I turn the key on an alarm sounds until I press the starter button. When I stop the engine the alarm sounds again until I turn the key off. So what you are describing about the panel sounds normal to me. My engine has trouble starting if I don’t throttle it up about half way before pressing the starter button. When it starts I then throttle it down to idle speed. Try that and see what happens.

 

[Woodrowbr]

I believe in the 1978 hunter 30's they put ysb 30's, not the ysm. If memory serves me the only difference is the ysb is a horizontal engine and the ysm is vertical. Otherwise as far as I know they are the same engine. At least that's what I've seemed to have gleamed from my 1977.

I think there are two alarms on that engine, low oil pressure and high temperature, but I'd have to look in the manual to be sure. Your alarm problem may be as simple as the oil pressure hasn't come up or that you have a faulty system in some way. If the engine isn't starting, you won't get oil pressure.

Slow turning engine may be electrical. Have you turned the engine by hand and does it spin freely? Should spin easily until hitting compression. If you've got compression...

If you can't find the manual for this engine online send me a note, I'll send you my copy.

dj

Finally made it down to the boat. Checked the engine plate, turns out it is a Yanmar YSM12 after all. Checked all the wiring as some of the posts suggested and found that the black wire that Connects to the engine was heavily oxidized. It was So badly corroded that when I started to remove the bolt which fastens it to the engine, the terminal end broke off. Unfortunately, as I tried to reconnect with a different/spare wire To see if this was the issue preventing ignition the bolt slipped and I dropped it. No idea where it landed. Looked for it everywhere For a good 20 minutes, stuck my hand in every little nook and cranny to no avail. The bilge troll must have taken it. Now I’m in need of a new bolt. Any idea on why size/threat Type that bolt may be? Still haven’t found a manual for the ysm12 to be able to look this up.Will update on progress (or if troll gives me back my bolt)

 

[Roland5048]

I'm assuming you dropped it in back of the engine. If so, there is a space between the hull and the pan that sits below the engine. There should also be a square, 6 inches or so, cover in the sole right at the bottom of the companion way steps. Remove it and pour some water behind the tranny and you will see it flowing to the bilge thru that square cutout. That's probably where your bolt went. You might be able to work something in there to push the bolt out or take a hose, run it under the pan and try to flush it out. Also, if the bolt is not SS, you might be able to finagle a magnet in there to grab it. Good luck.

 

[Woodrowbr]

I'm assuming you dropped it in back of the engine. If so, there is a space between the hull and the pan that sits below the engine. There should also be a square, 6 inches or so, cover in the sole right at the bottom of the companion way steps. Remove it and pour some water behind the tranny and you will see it flowing to the bilge thru that square cutout. That's probably where your bolt went. You might be able to work something in there to push the bolt out or take a hose, run it under the pan and try to flush it out. Also, if the bolt is not SS, you might be able to finagle a magnet in there to grab it. Good luck.

Thanks for the suggestions! Definitely going to give this a try over the weekend. Any idea on the bolt type/size in case a replacement needs to be bought?

 

[MikeHoncho]

Get yourself a telescoping magnetic pick up tool. Very handy,

 

[Woodrowbr]

After replacing the battery cable and purchasing a new hex bolt (turns out it was metric and not 5/16) Engine would not fire up. Got someone to help me check it out and after getting air out of system we were finally able to get her fired up and running!!! The excitement didn’t last long. Shortly after shutting it off and talking about other things that should be looked (about 15-20 min later) tried to restart the little yanmar and no go. After a few tries, the starter started to sound “loose” and free spinning a lot faster. Took it to a shop nearby and turns out the teeth on the inside of a plastic “cup” the gears spin around were all worn out. Guy charging 75 to replace just that plastic piece, 130 for the rebuild. Found a replacement (part number 104211-77010) started on amazon for around 110. Figured I would give that a Shot. Any experience with these replacement parts? I’ll post the link below for the amazon part.

New Premium Starter fits Yanmar Marine Engines YSB12 YSB8 YSE12 YSE8 YSM12 YSM8 1cyl 0.331L-0.510 Dsl 74 75 76 77 78 79 80 S114-194 S114-194R 104211-77010 104211-77011 17009 243-12125 S-8550 S114-134 Amazon.com: New Premium Starter fits Yanmar Marine Engines YSB12 YSB8 YSE12 YSE8 YSM12 YSM8 1cyl 0.331L-0.510 Dsl 74 75 76 77 78 79 80 S114-194 S114-194R 104211-77010 104211-77011 17009 243-12125 S-8550 S114-134: Automotive

 

[Tally Ho]

Never bought one, but there are only 7 left, so you better hurry and get yours ordered!

Good luck.

Greg

 

[Woodrowbr]

Never bought one, but there are only 7 left, so you better hurry and get yours ordered!

Good luck.

Greg

Just received it yesterday. Off to install It today!

 

[dLj]

Do report back, there are some of us quite interested in knowing what you think..

dj

 

[ggrizzard]

On your install/operational report.
Thanks.

 

[Woodrowbr]

Do report back, there are some of us quite interested in knowing what you think..

dj

Amazon.com: New Premium Starter fits Yanmar Marine Engines YSB12 YSB8 YSE12 YSE8 YSM12 YSM8 1cyl 0.331L-0.510 Dsl 74 75 76 77 78 79 80 S114-194 S114-194R 104211-77010 104211-77011 17009 243-12125 S-8550 S114-134 : Automotive

Buy New Premium Starter fits Yanmar Marine Engines YSB12 YSB8 YSE12 YSE8 YSM12 YSM8 1cyl 0.331L-0.510 Dsl 74 75 76 77 78 79 80 S114-194 S114-194R 104211-77010 104211-77011 17009 243-12125 S-8550 S114-134: Starters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

It worked!! Installed new starter motor (Amazon link included above) Connected that new starter and seemed to spin faster. After a few cranks it got the old yanmar going! Didn’t run engine very long because the starter switch has a continuous beep going (same as when engine is off but lower/softer volume). Worried that there actually might be low oil pressure or something is just not plugged in correctly. Any ideas?

 

[Woodrowbr]

I tightened all the bolts and connections that seemed like they could be loose. Took the oil cap and dip stick off and put them back on. After about 1.5hrs of cleaning the boat with engine off. I tried turning on the little yanmar again and fired up right away. This time the buzzer/alarm didn't sound. Not sure what was going on before.