Yanmar YSM8 handcranking problem

[Wotname]

Originally Posted by Compass790

It's lucky we are writing & not talking as I've had a few struggles communicating with my accent in the USA tho we both speak a form of English.
Shamed mitea bin the wrong word, maybe encouraged better. Well good on you for having a go @ it being a sparky. Hope it goes better than some of my attempts at being a domestic or marine sparky.lol. At least the 12v/24v on a boat is less hair raising than the 240v that has bit me a few times.
Hope ya knocked off early enough to get that sail in.

Nah, isn't wasn't the USA / NZ english barrier that caused any miscommunication. It was simply that the OP and I both bash electrons so we innately communicate better with each other than with metal bashers.

You and I do OK 'cause we have the advantage of being Tasman sea cobbers!
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Yep, it's winter social media thing...

[Teknishn]

Update on the YSM8 "adventure". Pulled the piston and connecting rod out this morning and now the hand crank rotates freely. 2 cracked piston rings and the oil compression ring is just plain worn out.

The problem with hand cranking, and starting the engine? Now, I've been going on information from the owner about what happened 2-years ago so I have to consider it somewhat suspect. I finally get a version of the story that starts to make sense. Owner tries to start the engine, and starter RPM's start to drop off and then the starter quits (It actually burned out..but he didn't know that). What I found today is that the connecting rod bearing was bad and had eaten up the crankshaft bearing surface (which created drag on the starter which then burned out...as they would), but not enough to actually seize the engine. I didn't drain the oil in the engine, the owner did, so I didn't have a chance to look for metal particles in the oil which might have clued me in a bit sooner, but that's in hindsight.

So now my job is done now (except for some cleaning up) and it's on the owner to decide what he wants to do. Grateful owner had 4 cases of beer and a carton of smokes dropped of on my boat and am now enjoying 3 more days in the marina gratis from the dockmaster for helping some of the less financially secure liveaboards (and most marinas/anchorages have a few) able to get their boats underway safely after sometimes years of being unable to do so, and in case they have to move if a hurricane threatens.

Two more boats to work on tomorrow: Replacing a depth finder, troubleshooting a fresh water system, replacing some track slides, and teaching a first time sailboat owner what all of his lines, sheets and halyards are for.

And here I was...thinking I was retired!

[Compass790]

Good that you've found the smoking gun. Fwiw I'd recommend getting a good used runner to replace engine. He can read my YSM8 rebuild mission here
:http://www.cruisersforum.com/forums/...-a-148914.html
I'd recommend a kubota based replacement normally but it sounds like he'd be better off putting back in another YSM8 so he doesn't have to change anything as he's obviously not mechanically minded.
I suspect you will find the the oil pump rotor has worn down into the case & so the oil pump clearances are too large & oil pump fails to prime properly or pressure is too low causing his big-end destruction ( & probly mains too ).
This is a common problem with them.
Anyway that's just for you to pass on to him whilst you have a smoke & a beer. :-)

[Teknishn]

Originally Posted by Compass790

He can read my YSM8 rebuild mission here
:http://www.cruisersforum.com/forums/...-a-148914.html

I'd previously read you YSM8 mission while researching this engine. Have passed it on. He already has a line on a running Beta 3-cylinder and gearbox from a local boatyard.

Many thanks to both yourself and Wotname for the input! Much appreciated!

[Compass790]

Wise choice! I lust after sisterships 3 cylinder Kubota on our pier & not just ( tho a lot) for the MUCH cheaper parts. Quieter & smoother & obviously more powerful ( 20hp). Not expecting to have to buy any more parts for our ysm8 tho, should outlast me ( touch wood)
happy to help you dig deeper in the noisy shaky beast.
cheers

[Wotname]

Originally Posted by Teknishn

Update on the YSM8 "adventure". Pulled the piston and connecting rod out this morning and now the hand crank rotates freely. 2 cracked piston rings and the oil compression ring is just plain worn out.

The problem with hand cranking, and starting the engine? Now, I've been going on information from the owner about what happened 2-years ago so I have to consider it somewhat suspect. I finally get a version of the story that starts to make sense. Owner tries to start the engine, and starter RPM's start to drop off and then the starter quits (It actually burned out..but he didn't know that). What I found today is that the connecting rod bearing was bad and had eaten up the crankshaft bearing surface (which created drag on the starter which then burned out...as they would), but not enough to actually seize the engine. I didn't drain the oil in the engine, the owner did, so I didn't have a chance to look for metal particles in the oil which might have clued me in a bit sooner, but that's in hindsight.

So now my job is done now (except for some cleaning up) and it's on the owner to decide what he wants to do. Grateful owner had 4 cases of beer and a carton of smokes dropped of on my boat and am now enjoying 3 more days in the marina gratis from the dockmaster for helping some of the less financially secure liveaboards (and most marinas/anchorages have a few) able to get their boats underway safely after sometimes years of being unable to do so, and in case they have to move if a hurricane threatens.

Two more boats to work on tomorrow: Replacing a depth finder, troubleshooting a fresh water system, replacing some track slides, and teaching a first time sailboat owner what all of his lines, sheets and halyards are for.

And here I was...thinking I was retired!

You sound busy

Well done for resolving the issue for the owner

FWIW, the starter motor on these engines are pretty lightweight. In fact the operation manual for the YSE8 suggests spinning up the the motor decompressed before dropping the decompression back to normal for a start. This greatly reduces the load (thus heat) on the starter motor but I wonder how many users actually do that.

If you are interested, you will probably find a goodly amount of bearing metal in the oil stainer/filter (the T handled thingy near the PTO pulley). Not many owners clean it regularly so it sits there accumulating metal.

Originally Posted by Compass790

.......
I suspect you will find the the oil pump rotor has worn down into the case & so the oil pump clearances are too large & oil pump fails to prime properly or pressure is too low causing his big-end destruction ( & probly mains too ).
This is a common problem with them.
Anyway that's just for you to pass on to him whilst you have a smoke & a beer. :-)

Yep, I have to concur with Compass here, very likely the oil pump is well worn and they are not so easy to repair. Doable but not easy! I think Compass has spend a considerable number of hours getting his sorted and I spent more than dollars (and time) than I wanted to getting mine back to original specs.

Like Compass, it seems to me the owner would be better off re-powering unless the oil pump is still reasonable.

Pass the YSM8 on to a Yanmar single cylinder enthusiast . For some reason, some of us like 'em - noisy and shaky!!!

[Teknishn]

Originally Posted by Wotname

You sound busy
FWIW, the starter motor on these engines are pretty lightweight. In fact the operation manual for the YSE8 suggests spinning up the the motor decompressed before dropping the decompression back to normal for a start. This greatly reduces the load (thus heat) on the starter motor but I wonder how many users actually do that.

Pass the YSM8 on to a Yanmar single cylinder enthusiast . For some reason, some of us like 'em - noisy and shaky!!!

Burned out my starter last year and now do this on my 1GM, spinning the engine until I hear the injector pop about 10 times. Rarely have to hold the start button more than 5 seconds in warm weather (Colder weather takes longer, naturally, due to having no preheat/glow plugs).

And yes, I kinda like my little under-powered glorified lawn mower engine!

For your entertainment, here's me last year pretending to be a metal basher and thinking I actually know what I'm talking about.

https://www.youtube.com/watch?v=HSBeCz0OIIE

[Wotname]

Originally Posted by Teknishn

.........

For your entertainment, here's me last year pretending to be a metal basher and thinking I actually know what I'm talking about.

[Compass790]

You look a lot more convincing than me trying to pretend to be a sparky
Your 1GM10 should start instantly, is the compression getting low?

[Teknishn]

Originally Posted by Compass790

You look a lot more convincing than me trying to pretend to be a sparky
Your 1GM10 should start instantly, is the compression getting low?

Not a 1GM10. Regular old 6.5 hp 1 GM. Good compression. New piston, rings, bearings done last year. Re-lapped the valves and replaced the oil seals as well. Doesn't smoke so I didn't replace valve guides or the pre-heater in the head. Injector original to the boat when I purchased it 2.5 years ago probably needs replacing. Just hit 2000 hours on the engine in my log so it's on my list...of many things.

[Compass790]

Again I didn't read post properly ( not unusual ) re 1GM & 1GM10. Not familiar with 1GM so didn't know they came with a preheater. If they come with one I guess they need one. Maybe their compression ratio not as high as YSM8? I Noticed yr injector nozzle dripping in vid, not a good sign but spray pattern looked ok. Valve guides dont seem to be a problem. Is the 1GM a replaceable wet sleeve model?
Like Wotname I hope someone either rebuilds or uses the dead YSM8 for parts. If i wasn't 6000 miles away I'd have a go. If the crankpin is destroyed ya can't buy another crank from Yanmar. They can be built up & reground but that's expensive.

[Teknishn]

Oops! Sorry, not preheater..should have been the precombusion chamber.

[Compass790]

Originally Posted by Teknishn

Oops! Sorry, not preheater..should have been the precombusion chamber.

Thanks for clearing that up, was a bit puzzled that a Yammer of that era had a pre-heater. I never touched our pre-com chamber in rebuild, never seemed to affect anything.

One more question to satisfy my curiosity if you can. Did the YSM8 owner disconnect his oil pressure alarm or was it kaput? I assumed lubrication failure to destroy his big-end like that.
No hurry for reply, you sound like a busy retiree!

[Teknishn]

Originally Posted by Compass790

Thanks for clearing that up, was a bit puzzled that a Yammer of that era had a pre-heater. I never touched our pre-com chamber in rebuild, never seemed to affect anything.

One more question to satisfy my curiosity if you can. Did the YSM8 owner disconnect his oil pressure alarm or was it kaput? I assumed lubrication failure to destroy his big-end like that.
No hurry for reply, you sound like a busy retiree!

The owner didn't disconnect the alarm and the sensor tested good. Broken wire in the harness. Temp sender was bad though.

Yep, busy retiree here. Now have a "real" job (pays in $) working for a local marine contractor for a few weeks to build up the cruising kitty a bit and buy engine spares for the 1GM, a bit more anchor chain, replace halyards and finally purchase a rig tension gauge (Loos & Co. Pro model)

[Compass790]

Originally Posted by Teknishn

The owner didn't disconnect the alarm and the sensor tested good. Broken wire in the harness. Temp sender was bad though.

Yep, busy retiree here. Now have a "real" job (pays in $) working for a local marine contractor for a few weeks to build up the cruising kitty a bit and buy engine spares for the 1GM, a bit more anchor chain, replace halyards and finally purchase a rig tension gauge (Loos & Co. Pro model)

Cheers for update..Oh that's a pity re broken wire.
Enjoy getting some $$$ in :-)