Originally Posted by Rusty123
That's a good point -- lots to be said for simplicity.
On a related topic, I notice that the service manual calls for a valve lapping every 1,000 hours. That sounds excessive to me, but as I've said, I want to keep it running for a good long time, and skipping maintenance doesn't seem like the way to do so.
I don't have the necessary tools or expertise to service the valves, so when I do it, I'd probably just pull the head and take it to a machine shop for the service (good opportunity to perform other work on and around the head).
It sounds like you take good care of your motor -- when and how do you handle the valve lapping requirement?
I have never seen a yanmar manual that calls for valve lapping. I see where they do call for valve clearence adjustment. I did adjust my valves a few months back. This was the first time I had done so in the three years I owned the boat. A lot of people skip valve adjustment, but I would do it every 3-5 years. With boat engines, we probably don't put many hours on an engine so I would stick to time not hours. Valve clearance was pretty straight forward, remove the valve cover and check- finding top dead center was the hardest part.
I would not take the engine apart unless you have a problem. Do not remove head unless you need to for a reason (engine broke). Taking old things apart is a sure fire way to break something-been there, done that.