Buying a boat

[rjtaylor12]

I'm very close to buying an older sailboat. My question is the motor. It's a yanmar 66hp 4jh-hte with no hour meter and a dubious date of installation " the 90's"? As I am not a wealthy man, I'm very cautious. How much should one discount for such a mystery motor? Any idea what it would cost to have it rebuilt? Is there any information to be gained from the model and engine number? Thanks in advance for your help!

[TacomaSailor]

Manufactured 1985 - 1989

I have a 4JH-2E manufactured in 1994 with 2850 hours on it and it is running like a top; smooth, clean, lots of power, no smoke, starts instantly.

I am from the Pacific NW where thousands of commercial fisherman run boats with one or two Yanmar engines (usually six cylinder). My mechanic up there maintained hundreds of them and said a Yanmar will run forever if it gets:
- clean air
- clean fuel
- regular oil changes

and is run hard and hot at least every ten-hours.

He said 10,000 hours was easy on a Yanmar.

You could get an oil analysis done and have an experienced Yanmar guy go thru the engine checking for problems. The following are the major problems I know about in the 4J2E line (1989 thru 1999):

- coolant water pump needs replacement every 2,000 hours or so
- exhaust elbow is very prone to clogging and can damage the heat exchanger (parts to repair my system were $2,200 at 2600 hours and I did all the work myself
- motor mounts are prone to breakage and sometimes the sheared bolt is hard to detect
- the oil heat exchanger is hard to see and inspect and can leak coolant

I'd have no concerns about a 30-year old Yanmar 4 series IF I knew the operational history

[rjtaylor12]

Originally Posted by TacomaSailor

Manufactured 1985 - 1989

I have a 4JH-2E manufactured in 1994 with 2850 hours on it and it is running like a top; smooth, clean, lots of power, no smoke, starts instantly.

I am from the Pacific NW where thousands of commercial fisherman run boats with one or two Yanmar engines (usually six cylinder). My mechanic up there maintained hundreds of them and said a Yanmar will run forever if it gets:
- clean air
- clean fuel
- regular oil changes

and is run hard and hot at least every ten-hours.

He said 10,000 hours was easy on a Yanmar.

You could get an oil analysis done and have an experienced Yanmar guy go thru the engine checking for problems. The following are the major problems I know about in the 4J2E line (1989 thru 1999):

- coolant water pump needs replacement every 2,000 hours or so
- exhaust elbow is very prone to clogging and can damage the heat exchanger (parts to repair my system were $2,200 at 2600 hours and I did all the work myself
- motor mounts are prone to breakage and sometimes the sheared bolt is hard to detect
- the oil heat exchanger is hard to see and inspect and can leak coolant

I'd have no concerns about a 30-year old Yanmar 4 series IF I knew the operational history

Thank you Tacoma I really appreciate your insight.

[Terra Nova]

What you need is a competent engine survey.

[rjtaylor12]

Agreed.