250 hour service on my Yanmars

[Dug]

Well, I just came back from my 250 hour service sea trial on my 240 Yanmars.

Couple of interesting findings. I thought I would share for the benefit of all.

I had 3 injectors cleaned up. The mechanics want to change them all our or rebuild them end of next season. That will be 4 years and probably 300-350 hours. They said it is crappy fuel, and keep using the conditioner/additive. It would be worse without it. The low sulpher diesel devils...

I will replace the belts on the front of the engines, they stretched after new, rubbed on a pump housing and it has worn a groove on the outside of the belt. That is some of the belt dust. They are basically fine, but I don't want a worn belt. I will keep the old ones for spares.

Valves were not in need of significant adjustment. Fuel filters on the engines needed to be changed, and we cleaned the turbo's.

Big deal was that on the starboard engine the mounting bracket (a Mack Boring supplied part) that holds the oil cooler for the transmission broke. The oil cooler has been banging on the top of the transmission and has begun to wear a hole in the cooler. We are pretty lucky we caught it rather than having a hole appear and oil or water go all over the place and potentially wrecking the tranny. So I will be replacing that part with a new one!

Oh, and also a leak has developed on the heat exchanger module, allowing small amounts of salt water out of an o ring and out from under the end plate on the stern end, so we will pull that off, clean it up, replace the o-ring and then I will repaint the area that is bubbling and peeling.

All in all good finds, and catches.

Not related but all in one day, the E-120 depth display started to tell me this weekend that the harbor water temp. was 108-125 degrees. Uh huh...

So after 17 months I need a new transducer... Argh!
Such is life... Glad it is the end of the season. It will be coming out of the water in 4-5 weeks anyway... I guess if we go offshore again, we won't have a temp gage. But it has me thinking maybe another temp gage would be good as a backup... any recommendations? No Dytek anymore.

All in all an expensive but good day. It could have been worse if we didn't catch these things and I am hell bent to take care of these beautiful engines!!!

Dug

[In Memory of Vicroy]

Dug - four cylinder, four cycle diesels set up a harmonic vibration at certain speeds, just the nature of the beast. My first encounter with this harmonic was in 1984 when I put the Vulva AQAD30DP duoprops in my B25. 4 cyl, 4 stroke turbo afercooled, 110 hp. Stuff just fell off them, every bracket that held a filter, etc. broke within a year. I went thru a half dozen alternator adjusting irons, finally made my own out of 316 stainless.

Rub chafe every hose, wire, etc. on your engines & boat with cheap rubber heater hose slit and wire tied on the hose or wire. Short money and time very well spent. I have done the same on AJ, with 6 cyl. 4 stroke Cummins, but she still shakes a lot at idle. Takes about an hour or 2 with heater hose and a bag of wire ties to do the whole boat. Just chafe proof anything that is touching anything else.

UV

[Dug]

Vic,

I actually have done that, at installation. The mechanic and I did identify a few more spots that would be beneficial to do, and I plan to hit them this weekend.

The oil cooler is one of them, but the bracket shouldn't have broken.

I am going to take a close look a the Port engine same bracket, to see if there are signs of wear...

You are right, chafe guards are worth the time and effort. No doubt.

Dug

[Mike Moran]

Dug how did you clean the turbo's ? thanks Mike Moran

[capy]

Say what you will about oil-slingin' dump truck motors.....but in 14 seasons I've never broke a a bracket or had to change the hoses...never had a coolant leak, replaced the belts about 6 years ago and they still look new.

Corrosion isn't a problem...everything is coated with oil, it's about time for my 5 year bilge steam clean.

Dug try putting a heavy ground wire # 10 or so to your bronze through hull.

I had a 16 ga wire on my first bronze thru hull and it crpped out after 2 years.

Switched to a 4 ga battery cable and the replacement thru hull out lived the display, about ten years.

[Rawleigh]

Dug: If that is a newer thru hull, the temp sender should be built in the paddle wheel assembly so it can be replace without changing the whole transducer. I used a Furuno kit to splice in a new style paddle wheel temp sender into my older transducer which had the temp built into the thru hull. It has a junction box and involves splicing the new temp wires into the old cable, but it does work, and you don't have to haul the boat.

[Dug]

It isn't a thru hull. Something in the ducer went, or malfunctioned. There is no paddle wheel, as there is no speed reading. We have to pull the boat to pull the ducer out of the fairing block. It may wreck the block, so we need a new one of them too.

We left the foam covers on, and sprayed the special japanese soap (that was the technical definition, I chuckled) in very slowly with a good mist. He said if it was sprayed in too hard and too fast it could damage the turbo vanes. Then it was rinsed with water.

There was some discussion some time ago in the past about how to clean them here, but this is what the mechanic did, and I went along to make sure that if there was something that went wrong, it was not my fault. I screw up enough on my own...

I probaby won't change it until winter when the boat will be out anyway...

D

[Carl]

sprayed the special japanese soap (that was the technical definition, I chuckled)

Gotta love that, working on Spindle of my Emco CNC lathe, the tech instructs me in his Heavy German accent "You must use Z Special Grease Mit Z bearings before installation...ya...I send to you Z Special Grease...ya". Sure enough the next day I get package from company with...you guessed it "Special Grease". Right on the tube itself, Isoflex NBU 15... Special Grease. I too chuckled, still do as I have the tube in the office so I can look at it and add some levity the day...

[In Memory of Vicroy]

I use the Special Coonass All-Purpose Wetting Agent for turbo cleaning....Blue Dawn dishwashing soap. 8 oz. distilled water and one oz. of Dawn swirled, not shaken....spray a stream into the turbo intake over about 4 minutes, then follow with 6 oz. of distilled water over 3 minutes. Gotta be done at curise speed underway with engine at full operating temp. A mist blows away in the 24 kt breeze, use a stream, won't hurt the turbo blades. Just shoot, wait a few seconds, pace yourself, and all will be well. Neat trick for any diesel, turbo or not.

UV

[Bruce]

I also use the blue dawn. Cuts grease real good and is cheap. Follow Vics instructions and it works fine.

It will only keep a well maintained turbo, just that.

An oily well caked carbon built up turbo needs to be removed and the cartridge cleaned in a hot parts cleaner.

A good way to see if the turbo is not performing well if your looking for problems is to use a boost pressure gauge.

On the Yanmar, remove the whole intake filter assembly. Don't do it thru the foam filter or the housing frame. But be careful. At speed the turbo is quite a vacuum cleaner.
If your not quite convinced, look at my post a few weeks back on that 30 grand Yanmar destroyed by sucking up an ice bag.

The 4 banger Yanmar has no balance problem at anything but low idle. But like UV said most do.

The D4 Volvo's I installed on the last 31 has a horrible shake between 1050 and 1125 turns.

Dug you must have really crappy fuel. Its extremely rare that I have to do any type of injector work under 1500 hours(detroits excluded) unless its a mechanical failure.
You best be using an additive on every fillup.

[Dug]

Bruce,

I have religiously been using Stanadyne at every opportunity.

I was as surprised as you sound. I don't buy fuel from any backwoods location, and both places are higher volume houses. I don't know what to say...

I appreciate the feedback and input Bruce.

Dug

[Bill Fuller]

Dug

I have a few questions for you. I have about 1900 hours on my 4LHAs in a B28 and have not so much as cracked an injector yet. I also have had very few vibration issues.

What were the symptoms that prompted looking at the injectors?

What do you have for fuel filtration? I assume the standard on-engine filter, but what else?

Also, if it was not done, be sure to check the exhaust manifod bolts. I was allerted to the fact that these may need tightening after a number of hours and mine were no tight enough. They have not needed retightening since and no other bolts have come loose.

You might want to coonsider an S&B air filter from Seaboard marine, they work great.

Although the standard raw water impellers are not a problem with the Yanmar pumps, Seaboard also offers there "improved" impellers for the Yanmars as well as the Cummins.

Like most, I have been completely satisfied with the 4LHAs.

Bill

[Dug]

Bill, thanks for the info!

at the 250 hour service one of the checks is the atomization of the fuel as it sprays out the injectors. I guess that would be how they found it...

There was no damage, but they were not spraying right. I guess they were dirty, and needed a bit of attention. As I said 3 out of 8 total. They want to look again at the end of next season as a preventative.

For filtration I have the on engine filter, and racors using the 10 micron filters (blue or brown, there was a change recently...)

Good to know about the manifold bolts. I will check, along with the other bracket on the port engine!

Overall, I love my engines, and want to treat them well!

D