bum yanmar outboard replacement

J Page · Jan 8, 2009

Last resort

This would be a last resort for me.I have the same boat as you. Many people have comments on this topic in the archives so check it out. My opinon is

1. 25 hp is way to heavy for your stern transom. Most use 9.9 w/ a long shaft
2. If your sailing in an area that is prone to steep waves, prop may come out of the water and freewheel. Not good for the boat and can be damageing to the motor, and a safety issue if you shear a pin.
3. Controls will be challenging to mount at best. If not ran to the cockpit your hanging of the edge of the transom to throttle, shift ect. Taking your eyes off your target, sounds like a recepie for comedy at best.

4. Now you have to route fuel lines below,(new holes in the boat are never a good idea) and mount a Gas fuel take below( get a good blower, and remember to use it each time before starting or possible BOOM!

To me this sounds like too much to do. An engine fix might be expensive but all the rest is going to add up, and then has to be fixed when you switch back. Some people have done it, but to me a repair or repower would be the way to go. What's wrong with the YSM-12? Symptoms?
Post those, the people here can help alot.

Pray for wind,
Lugeman

Ed Schenck · Jan 8, 2009

Agree with Lugeman. Friend on our lake had one, about 10hp. Didn't motor well and difficult to start and run with controls on stern pushpit rails. Almost impossible to get the motor low enough, even with the long shaft, and then raise it for sailing. Then there is the gasoline problem.

Depending upon the problem it is usually repairable right in the boat.

Manny · Jan 8, 2009

25 hp sounds like it's way to big, maybe a 15 hp would be okay. How are you going to mount it? Is there an adjustable mount out there that can handle a 25 horse outboard?
One thing to consider is that a good outboard mount is expensive even for a small outboard. You would probably spend as much on the mount as the rebuild kit.

Manny

Benny · Jan 8, 2009

Try using a thick oil with an additive added to it like STP. That should improve your compression and help maintain oil pressure. If no improvement with oil pressure your bearings are likely shot.

Bill Roosa · Jan 9, 2009

Low oil pressure

Oil pressure is maintained by the main and camshaft bearings. All other oiled parts are supplied through a restrictor (orifice). It is unlikely that the orifice has "worn out" so that leaves the bearings. The fact that the oil pressure goes down as the engine heats up is consistent with early bearing failure. The fact that she gets noisy is consistent with catastrophic bearing failure.
The fact that she smokes up the cabin is not related to bearing failure but since the oil pressure is reduced the oil rings in the pistons are not getting the quantity they need and the piston sleeves/rings are scored. Allowing combustion gasses to get into the crankcase. Your crankcase ventilation (PCV valve??) should take care of this so the smoke does not get outside the engine. You should check this as carbon monoxide (CO) could be escaping to the cabin even when she is not smoking. See below
It is only going to spiral downward from here.
Bearings are replaceable parts IF you don't eat through them and start grinding crank shaft or journal parts. Piston rings are replaceable and piston sleeves are honable. The amount of time you will need to do a rebuild of this type is about a weekend. I've done it in an afternoon but that was not my first rodeo. Postponing this can get prohibitively expensive.

Positive crankcase ventilation in diesels.
There should be a rubber hose running from the valve cover to the air cleaner or intake manifold. This allows all blow-by to be pushed into the intake manifold where they can "sucked" into the engine and be burnt. Check for hose failure. This is a big CO concern. More important than your power problem. You need to find out exactly where the smoke is coming from and fix it. Don't become a statistic.

Clark · Jan 9, 2009

Please listen to J Page and make immediate plans to . .

repair your engine. You'll spend $200 - $400 on a bracket, tank, hoses, controls and you'll wind up with an unsatisfactory if not unworkable solution. If this were a 25-27 I'd say maybe . . . .

kloudie1 · Jan 10, 2009

Quick thought.. Has someone checked the oil pressure control valve ?? There is a small ball valve in the block (usually) that dumps oil to sump before the filter and controls the pressure that the bearings and stuff see. If a small bit of debris gets under the ball, the engine will show low oil pressure after warm-up. Something to check.. I am not familiar with where it is on that engine. It sounds like the bearings are whacked out already from low pressure, but do check the pressure control valve.

baysailllc · May 24, 2009

flhunterowner said:
OK.. best bet seems to just rebuild and forget the outboard..

Next question.. has anybody removed a YSE12 from a hunter 30?
If so, how did you get the motor out the cabin door (will it fit).

Since the boat is in the slip and I cant get any type of lift over the boat,
I am wondering how to manuever the motor out of the boat.

Anybody have an idea what a YSE12 Weighs?

thanks

I needed to rebuild my YSM12 last winter. I opted to take only the engine and leave the reverse gear housing and rear mounts, shaft and coupling in place. I unbloted the crankcase off the front mounts, unattached all the lines, wires and hoses, and detached the clutch housing. I opened the shifter housing and removed the shifing collar. Using the boom and a boom vang for a tackle and attached to the motor I physically rocked and twisted the engine through the opening and onto the salon deck. I'd guess the weight at 200-225 lbs without the clutch housing. I had a local commercial dock hoist the engine out of the boat into my trunk for me for a six pack.
After the overhaul this spring I lowered the engine at the commercial dock into the cabin. I used a small roller jack and the boom and vang and wrestleld, pushed and twisted the motor back through the opening. The roller jack was critical to aligning the clutch with the housing and getting the engine up once inside the "hole". I removed the altenator, water pump, alternator brackets, fuel pump before attempting this. I also had to turn the starboard forward mount so the waterpump mount wound not be in the way.
This method is crude, potentially dangerous to the woodwork and if not done with a boatload of luck a bad outcome is possible. I worked alone and spent about eight hours on removal and installation with the boat in the water.
I would guess a boatyard would have to haul the boat and put two men on it for a day to take apart the interior and remove the complete engine. There would be crane truck charges too. I figure the total overhaul cost me around $3K. Just about what a good boatyard would charge just to haul the boat take the engine out and put it back in and relaunch.
The engine had been in the boat for 31 years and the only appreciable wear was the conrod bearing. Piston, liner, crank, all within serviciable limits. We were amazed with the good condition of the internal surfaces after all that salt water!
Bottom line is you can do it, just go easy and be careful.

bum yanmar outboard replacement

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baysailllc