440 Yanmar

[Capt2020]

Looking at a boat with a 440 Yanmar.. 1000 hours on it. Does anyone have any good experiences with them? Are they really that bad? Does anybody have this engine with 2-3 thousand hours?

 

[Blitzen]

The 440 was the problem child for Yanmar. Do a search on valve issues and I am sure you will see a lot of problems. i know of a few boats that have had them replaced by Yanmar with new re-mans.

 

[MDI45]

A 31 J.C. That iam rebuilding has a 440 in it ....i think she has 1800 hours on it

 

[djmarchand]

Yanmar has had problems with this engine. They are very sensitive to overpropping. If this boat doesn't hit 3,400 rpm or more at wot in gear, then it was probably overloaded. Prop it to 3,500 if you buy it and you could get decent life if you cruise at 2,800 or less.

David

 

[Capt2020]

Thanks guys for the import. Both things make sence to me. One other person suggested stack temp gauges. I know that some of the party boat people in NY just go by stack temperature.
Blitzen do you know if changing the values worked?

 

[eyschulman]

valve change is of value. also be careful with exhaust elbow make sure the shower is well above waterline and rest of system then runs down hill. Two things blow these motors 1. overload causing excessive heat at valves. 2. moisture coming back from exhaust to valve area.

 

[captainlarry84]

There was a run of soft metal valve stems that met with problem. Yanmar stood by the issue and did the repairs. The repair should be done before the valve drops. Once it drops it is big issue. I would get the serial # off the motor and see if it is part of the run. If so I would research what Yanmar will do at such a late date.
TRUE ABOUT rpms you need to get it all 3300 RPMs under full load. On a spring splash the motor should true 3500 RPMs. This way in mid season you settle in at 3350 RPMs.
Pyrometer excellent idea. I always use them. The 440 should run at 1180 degrees continuous & 1280 & WOT. Gear is also important 2:0 & 2.5 gear works the best. all in all a good motor.

 

[captainlarry84]

A 31 J.C. That iam rebuilding has a 440 in it ....i think she has 1800 hours on it

I believe that rig has the 440 electronic motor with the new 4 valve head an excellent motor.

 

[captainlarry84]

Looking at a boat with a 440 Yanmar.. 1000 hours on it. Does anyone have any good experiences with them? Are they really that bad? Does anybody have this engine with 2-3 thousand hours?

What type of boat? wheel size? Gearing less run some test numbers on the boat. I am sure I can get you very close. Also RPMs at WOT.

 

[MDI45]

I believe that rig has the 440 electronic motor with the new 4 valve head an excellent motor.

Larry,Do you think it is possible that this motor is part of the weak valve issue?

 

[Capt2020]

Ok I am taking this all in. The boat is land lock by boats right now. Can't do any rpm testing yet. Maybe in the next couple of weeks when I will do the sea trial. I have put a deposit down on the boat. I'm sure most of you guys have seen it around. So I will call Yanmar with the serial number and see what has been done or what can be done with the engine. Will also find out if this engine was in the soft value zone. Always appreciated!

 

[captainlarry84]

NO

Larry,Do you think it is possible that this motor is part of the weak valve issue?

No The valve issue was on the early 440 mechanical motors. The motor in your JC Express was much newer and a very different motor with an completely different head assembly. The head was not changed because of the earlier problem it was changed for the purpose of meeting Tier emission level. The 370 was also changed.

 

[Capt2020]

thanks Larry for taking the time to take those pictures and post them. I usually only put 300 hours or so on an engine per year. We hope to get 2-3 season out of it. Run it easy is the answer I guess. I will probably buy the boat as long as it doesn't smoke to bad and if I can get the RPMs. Was going to get an oil sample but 0 hours on the oil. Thanks

 

[MDI45]

No The valve issue was on the early 440 mechanical motors. The motor in your JC Express was much newer and a very different motor with an completely different head assembly. The head was not changed because of the earlier problem it was changed for the purpose of meeting Tier emission level. The 370 was also changed.

Larry,Thank you very much for the info on the 440....I will pass it on to the owner

 

[captainlarry84]

Larry,Thank you very much for the info on the 440....I will pass it on to the owner

He has no issues. I always though that boat could take a little more wheel. Norm was very easy on the boat. That motor also comes in 480 HP.

 

[MDI45]

He has no issues. I always though that boat could take a little more wheel. Norm was very easy on the boat. That motor also comes in 480 HP.

I will check to see what size wheel is on there......what size would you suggest?

 

[captainlarry84]

I think he has a 22 X 22. I think the boat could swing either a 23 X 23 or 23 X 22

 

[MDI45]

I think he has a 22 X 22. I think the boat could swing either a 23 X 23 or 23 X 22

And he should get 3500 RPM on a spring splash?....Also Rich Hunter wanted me to ask you what ratio gear you had on the 370 Yanmar.....because he just picked up a 375 3208 for his new 36 Stanley and is undecided about gear ratio

 

[blackdiamond296]

And he should get 3500 RPM on a spring splash?....Also Rich Hunter wanted me to ask you what ratio gear you had on the 370 Yanmar.....because he just picked up a 375 3208 for his new 36 Stanley and is undecided about gear ratio

Not to derail the thread- but is that the same Rich Hunter that used to be in the Freeport Tuna Club and stretched his Webbers Cove himself? Haven't heard about or talked to him in years! If it is, please say hello for me.

Now the job he did to that other boat- that would be a DEBF conversation starter for sure!

 

[MDI45]

Not to derail the thread- but is that the same Rich Hunter that used to be in the Freeport Tuna Club and stretched his Webbers Cove himself? Haven't heard about or talked to him in years! If it is, please say hello for me.

Now the job he did to that other boat- that would be a DEBF conversation starter for sure!

yes it is...and i will