Thoughts on Yanmar 3JH2E

[polhoff]

35 Hp, 3 cylinders.

Any comments please.

 

[westhinder]

I have a 3JH3E, now 19 years old, which I suppose will be broadly similar. In 7 years of ownership I have had no issues with the engine. It runs smoothly and always starts without hesitation. The starter failed to disengage and demolished itself one day, but I do not think that has anything to do with the reliability of the engine itself.
I would like to have a word with the guy who dreamed up the position of the waterpump though. I bet he never had to change an impeller or he would have thought twice before having it face backwards.

 

[VicS]

I have a 3JH3E, now 19 years old, which I suppose will be broadly similar. In 7 years of ownership I have had no issues with the engine. It runs smoothly and always starts without hesitation. The starter failed to disengage and demolished itself one day, but I do not think that has anything to do with the reliability of the engine itself.
I would like to have a word with the guy who dreamed up the position of the waterpump though. I bet he never had to change an impeller or he would have thought twice before having it face backwards.

Not the only engine with the waterpump similarly located! some are evn worse

 

[vyv_cox]

Not the same engine but I am most impressed with my Yanmar 3GM30F. 2600 hours in about 19 years. Manifold and pump replaced, one of each belts, impellers and filters. Thats all, uses very little oil, starts first time even after an 18 month absence.

 

[UK-WOOZY]

same on my 2GM20, bloody annoying how the pump is on the other side of the belts requiring the alternator being loosened to loosen the pump belt to get to the bolts to undo the pump to then be able to change the impeller. wouldnt want to do this in haste. i envy other makes that have the impeller easily accessible

 

[jiris]

I bought the turbo version of this one with allegedly 1,000 hours on the clock (from some signs I do think it has about a double of that) 2 years ago and put about 600 hours of hard use on it already. It runs like new, it is extremely economical (note the turbo though) and it doesn't show any signs of serious wear. Nothing leaking from anywhere and it fires without exception at the moment the first cylinder completes its compression stroke. A masterpiece of engineering.
As for some other posters complaining about the position of water pump: It largely depends where you have the engine mounted. I have easy access to the engine from the exhaust side and have no problems getting to it. I removed the impeller once (just to check it). I found it it 100% and I would guess it probably wasn't the first one. My only problem was pulling it out and pressing it back and I was surprised I managed to do without damaging it in the end. A prick of a job, probably very tight tolerance on the spline. Anyway, if you want a really good engine, don't look any further.

 

[olam]

I also have the 47hp turbo version.Starts on the first revolution even mid winter.
20 years old but runs like new.
The Yanmar gearbox is not quite so impressive,Can have slippage issues.

 

[westhinder]

The Yanmar gearbox is not quite so impressive,Can have slippage issues.

We had serious slippage on the gearbox after catching a fishing net in the prop. Inspection showed that a number of rings (don't know the technical name) had been deformed. Replacing them was not cheap, but fortunately the insurance picked up most of the bill. Now all is normal again.

 

[polhoff]

Ok, thank you for all replies. The general view is that they are excellent, even the old ones, although the position of the water pump could be better.

Thanks for input.