Yanmar 370hp

[Captainpete12]

I am thinking of purchasing a Mainship 430 (2002) with Yanmar 370HP. I have always had good luck with Yanmar but only small ones on a sailboat. These have 3320 hours on them and I will obviously have a comprehensive diesel survey done. Is there anything in particular I should look for or know about ? I would appreciate it. Thank you!

 

[DavidM]

I have had two boats with those engines over the years, obviously not the boat in my avatar . They are solid, reliable and will give you long life if you operate and maintain them right. Operate means making sure they run at 3,300+ at wot and run them at 2,800 rpm or less routinely. Maintenance means changing lube oil according to schedule, keeping the zincs up, cleaning the raw water system if wot temps get above 200 F. (Barnacle Buster or similar) and removing, disassembling, cleaning both sides, reassembling with new gaskets and lots of grease, and reinstalling the after cooler every five years as well as changing the antifreeze.

Here is a comprehensive checklist for that engine that is better than any general surveyor will do and probably better than many engine surveyors. See the attachment.

David

 

[Captainpete12]

Thank you for your input. I really appreciate it. I have requested all service records from the seller, including any major work done and who did it (preferably a professional). I will also have a diesel survey done apart from the regular survey. I have been told these Yanmars can run well up to perhaps 10,000 hours (interesting)

Capt. Peter Kane
Osprey Marine Ltd.

 

[DavidM]

I have been told these Yanmars can run well up to perhaps 10,000 hours (interesting)

Capt. Peter Kane
Osprey Marine Ltd.

Yes they can go well beyond 10,000 hours. Tony Athens who owns a diesel maintenance, repair and new engine sales shop in Ca, installed a Yanmar 370 in his brother’s commercial fishing boat. After 15,000 hours (and it was stlll running strong), Tony replaced it with a Cummins out of an abundance of caution.

Admittedly, the Yanmar got the best maintenance possible and wasn’t run very hard. But even so, 15,000 hours is nothing to sneeze at.

The Mainship 430, does it have twins? If so 15 kts or so should be possible at about 2,800 rpm’s. If a single, then you can only go displacement speeds.

David

 

[Captainpete12]

It does have twins.

 

[Fleming]

Here is a comprehensive checklist for that engine that is better than any general surveyor will do and probably better than many engine surveyors. See the attachment.

David

I think you shared the wrong list, it's titled "abbreviated" and that seems like an accurate description.

 

[Captainpete12]

Any others would be greatly appreciated.

 

[Bacchus]

I agree w David (as usual because he's correct)

If current oil has some hours on it I would pull samples for analysis.
You could do the same w transmissions.
I dont think I would sample coolant if it's clear & clear but that's also possible of any questions about cooler condition.
You should be able to get good clues from maint records... most folks that keep good records are also diligent about maint. The opposite is also generally true.

 

[E-Sea Going]

Yanmar 6ly3-EPT

I have twin yanmar 480 H.P. (6ly3-EPT) on my Mainship Pilot 430, I've never had an problem but I do keep up with regular PM. I would not hesitate to buy a yanmar.

 

[Captainpete12]

So far, so good. I like what I am hearing from you guys! I have requested records of all work done on this vessel by the present and past owners. If they indicate regular maintenance and any repairs and the survey turns out well it is a buy. Thank you.

Capt. Pete

 

[sunchaser]

Capt. Pete
As Dave noted, a complete after cooler removal and servicing is needed with some degree of frequency. If seller cannot show proof of a recent said service I'd make that activity, by a reliable tech, a part of the sale process and done prior to sea trial.

 

[DavidM]

Capt. Pete
As Dave noted, a complete after cooler removal and servicing is needed with some degree of frequency. If seller cannot show proof of a recent said service I'd make that activity, by a reliable tech, a part of the sale process and done prior to sea trial.

David

 

[Bonedoc]

I have been running a Yanmar 6-LPA for the past 4 years.
I am at about 600hrs with no engine issues to date and have kept up on scheduled maintenance.

Upon recieving the boat I changed out all the engine hoses and belts. Last year the coolers were pulled and serviced and found to be in good shape.

I do the basic maintenance including seasonal fluid and filters, zincs, impeller, and regular “ rust patrol” where I wire bush, prime, and spray any areas needing attention.

Motor is strong, reliable, and starts quickly upon the turn of the key.

Parts and service are not difficult to find.

There is an online forum for Yanmars and your model as well.

Happy with my Yanmar motor.

 

[mcaudell]

I have a single 6lya-stp in a 01 pilot 34. It has 800 hours on it. Runs 16knts at 2800 all day and doesn’t burn much diesel. Has some smoke at startup, buts that’s all.

 

[Bonedoc]

At 3200 RPM achieving 17knts my fuel burn is low as well at 10 g/h.