[Sunphish]

In over 50 years of sailing I am now in a position to move up to a inboard powered boat to enjoy in retirement.

I have identified a 1980 boat that is in excellent condition and is powered by the original ysm8. I believe the boat to have been a freshwater boat for about 30 yrs and a saltwater boat the last 5. The boat had an extensive refit in 2012 with some replacements being done to the engine, as follows:
New Alternator
New water pump impeller
New Thermostat
New Zinc
New Motor mounts
New engine shutoff lever
New Fuel Filter
New fuel lines
New Water Strainer
New Belt
New hoses
New temp sender
New Alarm horn
New Cutlass bearing
New coupler
New Prop shaft
New Bronze Prop LH 12X8

All that having been done, my concern remains that things never last forever, and there is really no way to determine internal corrosion without a teardown.

Assuming it were to pass a mechanical inspection by a Yanmar certified tech, what is the realistic longevity of a ysm8? What is the $ value of this engine if I were to decide to just pull it and replace? I don't want to spend my ownership waiting for the shoe to drop. Finally, if I were to replace, give me a ball park on $$ for a replacement.

Thanks a lot, I'm sailing alone in a fog on this one.

 

[aa3jy]

A good place to start is by looking at the engine manual..

http://www.devill.net/Documentation/Yanmar/YSM-8-12.pdf

..if the vessel didn't come with one.

 

[paulk]

Not exactly the same, but we have a 1982 Yanmar 3GM down below on our boat. Ours is raw water cooled, which tends to lead to corrosion issues in salt water. You don't say how yours is cooled, but ours has only had fresh water run through it when we are up rivers or when we put in antifreeze at the end of the season. In the past dozen or so years since we bought the boat we have replaced many of the same parts as on your list. We use the recommended oil and replace the anodes in the cooling system regularly.The main hurdle we had was keeping the batteries charged so that she'd turn over and start. (We have a crank for hand starting, but haven't ever been able to make it happen.) A solar panel with a trickle charge has solved that issue. We're still alert for any major problems that might develop, but she still seems happy as far as we can tell.

 

[Koinonia M27 323]

i have a 1980 ysb 8 in a Mirage 27. The engine (knock on wood) is original and has been maintained to manufacturer standards. I change the oil twice a season, watch for cooling water and inspect the exhaust for proper water return, so far so good. quite noisy, knocks a lot but mechanic here cant find anything wrong except "its a single lunger, so expect it". starts every time, uses about .8 ltr per hour at 80% throttle when motoring. pushes almost hull speed when full out. Cross my fingers it will be gr. children worrying about replacing it, not me.

 

[SloopJonB]

I had a YSM8 new on a pallet back then. If you've already been sailing for 50 years it's your kids or grandchildren that will have to worry about that engine.

The original basic engine was built with no accessories like a starter to run water pumps in rice paddies in 3rd world countries - it will shake your fillings out forever. Engines just don't get more reliable or long lived.

 

[Airuser]

We have a YSM8 that I have had to rebuild because of lubrication failure. Things to watch are oil pump wear, engine anode & exhaust elbow. The oil pump rotor slowly wears down into the case until the clearances get too large. Yanmars answer is to buy a new engine case but it's easy to file down to get back to tolerance. I recommend putting a tee ( 1/8th NPT) where the oil pressure sender fits & adding an oil pressure gauge. Parts are very expensive here in NZ. Check the exhaust elbow as recommended in workshop manual as if it leaks raw water can drop down on top of the exhaust valve. You can get stainless steel ones on Ebay which I would go for if I wasnt capable of building my own.. Ours lives in salt water but we rigged up a system to fresh water flush every time we come back to marina before shut down.
Agree with other posts it's a noisy shakey beast but simple & reliable if you keep an eye on maintenance. I like it as it's easy to work on & I suspect it will last another 30 years. Have no idea what a used one costs as dont know where you live but probably around $650 for a running one here. Hope that helps if you bought the boat

 

[hipopp]

anyone have any experience with a noisy knocking yanmar 8hp? seems to want to go on forever...

 

[SloopJonB]

anyone have any experience with a noisy knocking yanmar 8hp? seems to want to go on forever...

They're all like that.

My YSM8 would shake your fillings loose - at idle it would vibrate the lifelines to invisibility - but it ran & ran...