Unusual Yanny 4JH3 issue

[Snowtanned]

Looking at an older Catalina that has a stock 4JH3. Hobbs shows it has 100 hours on it. I'm a little concerned with the low number of hours. Knowing these things are made to run, not sit, I can imagine this may create a few problems. Does anyone have experience with this situation, or can give me some idea of what I might expect to be dealing with as a result of lack of use? BTW - she starts and sounds great.

[Paul L]

Those Yanmar hour meters have a propensity to failing. Maybe it was replaced. Do you know enough history of the boat to think a 15 year old engine only has a 100 hrs?

[Snowtanned]

Actually, sadly, I do.

[Paul L]

I'd say you are lucky to have an.essentially new engine. Do the standard Yanmar specd maintenance and enjoy it.

[Wotname]

Welcome aboard CF, Snowntanned.

Is there any maintenance history available?
When were oil changes carried out, was it run regularly (and up to operating temperature and under load) etc. Have the fuel lines ever been replaced? These things can a big difference!!

For instance, I have a 16 year old Yanmar 2GM20, (9 years still it was commissioned) and 300 hours on it but it has had oil changes about every six moths, new anodes every two years, new impeller every two years, block flush every 4 or five years, run every month and so on.

[GordMay]

Greetings and welcome aboard the CF, Snowtanned.

[doug1957]

I bought a boat that had an engine that had not been used much at all in the last 10 years. Maintained, but PO sailed on and off the mooring most of the time, and I doubt it rarely got up to temp. Ran well enough the first year, but there were signs of trouble ahead - lower compression on two of the four cylinders, some coolant in the oil at an end-of-year oil check, burning oil under load and new damper plate in the offing.

If this is the boat, get the engine checked as much as you can, get maintenance logs, and sea trial the engine with a mechanic on board. That's about the best you can do. But I think you really won't know what sort of shape it's really in until you use it as intended for a season. It would be a good idea for an oil check at the beginning of the season and an oil check before it's changed to see what's up.

[hamburking]

If the engine had a lot of hours on it you would also have concerns. When it comes down to it, you can only tell if its running well right now. And I can promise you that it doesn't matter if the hours are low or high, at some point in the future its going to need some dollars. The best you can do is be sure it is running well right now.

[JD-Odyssey]

You may want to take a look at the fuel tank and how long the fuel may have been sitting. I agree with some of the others who recommend taking it out on a trial run with an engine mechanic... check the exhaust, check if it comes to the expected RPMs, etc.

[Windcall]

Also check fuel tank. A cruiser had one with 500 hrs it plugged up in Cape cod canal he drifted through the bridge.

[a64pilot]

Originally Posted by Paul L

I'd say you are lucky to have an.essentially new engine. Do the standard Yanmar specd maintenance and enjoy it.

I go with this.
Mine when I bought her had less than 500 hours and was 27 yrs old.
Three years later and maybe another 500 hours, and all has been fine.
Change the coolant and oil, and adjust the valves, remove the injectors and have them cleaned, stuff you would do anyway for any 15 yr old engine.
However as has been said have the fuel tank cleaned, I did have issues on delivery with gunk in the tank clogging my fuel line, got good at emergency anchoring, but that could have been prevented easily by having the tank cleaned.

[Group9]

My 4jh had 700 hours and twenty years on it when I bought it. Had 2700 on it when I sold it seven years later. Never had one single thing break on that motot!