Yanmar 4HJ3HTE 1999 year model (although the boat was built in 2001). 2500 hours. 2000cc, 100 hp, turbocharged and intercooled. When I bought the boat it had 780 hours on it so I've used it a lot.
1. Starts instantly in any weather
. Look at it sideways and it[s already running. I've never used the air pre-heater, not even in below freezing weather
. I'm not even sure it works!
2. Gear-driven camshaft -- no timing belt, no timing chain!
3. Makes a lovely sound, as if it's pleased to be running. Very smooth -- sometimes I could swear it's a six cylinder. Very quiet -- like half the noise of one of the big Perkins
. Runs clean and happy at any speed from 1000 RPM
to 4000 RPM.
4. Doesn't burn or leak any oil. Coming from a Westerbeke
4-108, this is almost impossible to believe, but it leaks not a drop -- literally, not a drop -- of oil. As a result, engine room bilge
and outside of the engine, and engine room walls and ceiling, and other gear
in the engine room -- stay nice and clean.
5. Has been completely reliable.
6. Came from the factory with second alternator
7. Except for raw water pump
, everything is easy to get to.
8. Very compact and light for a 100 hp engine. Slightly more than half the weight of an 83 horsepower Perkins.
9. Lift pump is built into the injection pump. Eliminates risk of diesel fuel in the oil via punctured diaphragm
. There is no diaphragm
because it's a roller type.
driven injection pump -- no timing belt or chain.
12. Impellers last forever. Maybe not a Yanmar-specific feature, but rather a function of raw water pump
below the waterline, so it's always well primed.
1. Smokes like a chimney, especially when cold. Has done so since I bought the boat, and I almost didn't accept the boat from the seller as a result. Three mechanics and two surveyors couldn't find any problem with the engine. The injection pump went to the test and calibration rig, replaced all injectors, overhauled turbo (all at the expense of the seller) -- nothing helped. The second surveyor
said "They All Do That"
. I've lived with it now for all these years and it hasn't changed.
2. Poor engine electrics -- starting circuit. Apparently typical for Yanmar. Solved
by adding a relay to the solenoid circuit.
3. Raw water pump
hard to get to, and will douse the starter with sea water if you forget to close the sea cock.
4. Expensive parts, sometimes hard to get, through Yanmar's tightly controlled distribution network. No way to get parts from tractor dealers since these engines are made exclusively for boat -- there is no tractor version.
5. As others have mentioned -- horizontal oil filter
. HATE this.
All in all, though it has a couple of weak points, I have been very pleased with it. Most of all -- I like that it's smooth running and sounds good. As a result, I don't mind starting it and motoring in a calm.