smokey shakedown

[special k]

out yesterday for my shakedown cruise. everything seems good so i bring my yanmar 6lpa to wot. after a few minutes at full power we start losing power and thick, sooty black smoke. since we were already near some good fluking grounds we made a few successful drifts before limping back to mystic.

boat seems to start and idle well but no power above 2000-2200 rpm and thick nasty black smoke.
i have not yet changed my fuel filters this season (about 50 hrs on them) could my problem be as simple as this?

only my second full season with diesel power and coming due for 500 hr. service.

any suggestions?

[Cape Codder]

I have no isdea if the filters are the problem.
But my 10 micron filter mounted on the engine had less than 100 hours from last season.
I checked with Mack Boring who INSISTED that it must be changed EVERY SEASON, along with the 30 micron Racor.
Did it, no issues.
Perhaps you should change them and re-run.

[DougSea]

Black smoke is caused by incomplete combustion A quick guess is that your turbo is stuck. Although the fact that you were at WOT and then the problem arose is odd.

On my prior boat with the Penninsular the same thing happened when I went on my first run in the spring one year. I had just had the prop tuned and was all excited to check it out. Idle out of the speed zone, throttle up, and the same thing. Won't turn RPMs and when I look over my shoulder there's a black smoke screen behind me. Call the mechanic the next day. He calls me back an hour later and says "turbo was stuck. We unstuck it. You're good to go. No charge." Apparently this is not uncommon when turbocharged boats are laid up for the winter. In fact it happened again two years later. I unstuck it myself by taking off the air cleaner and spinning the shaft with a wrentch.

On the Penninsular you can see the turbo and can tell if it's turning. I don't know if you can see it on the Yanmar, but if not, try rapping on the turbo with a plastic mallet...believe it or not I had to o just that on the seatial of Sonny IV! (Volvo has everything covered up, but I have boost gauges and knew I didn't have a spinning turbo on the port engine)

Hope that's your fix too!

[special k]

i called bayside marine of mystic and they have a tech there now.
first finding is the turbo turns by hand but air filter soaked with salt water.
looking for raw water intrusion to the engine compartment now.............B.O.A.T.

[jleonard]

air filter soaked with salt water.

Not good. Let us know what the Bayside boys find.

While the subject is at hand....I changed from a standard paper air filter to a lifetime, reusable, cleanable air filter when I had my Cummins 6BTA in my previous boat. Better air flow PLUS if you end up with a "water event" a paper filter is ruined and you are down. Where a renewable filter can be rinsed off , dried, and you're good to go.

[special k]

after bayside called an told me of saltwater getting in the aircleaner i remembered that when changing zincs the oil cooler spun on me. i thought the entire unit had turned within it's clamps but apparently i turned the end cap breaking a gasket. new oil cooler gasket, good cleaning of turbo, oil change, raw water impeller and i'm good to go.

expensive DIY zinc change!

[RobS]

Yes, black smoke is too much fuel, not enough air. So you broke the gasket at the oil cooler end cap. Did you end up mixing the raw water into your engine oil or was the raw water just leaking into the engine room?

Another reason to do all maintenance on a regular basis, it keeps the connecting parts inspected and serviceable, ie. zinc nuts, water pump bolts, tranny coupler bolts, hose clamps, etc.

[special k]

yes, some water in the oil, fresh oil change already done.

as for the zinc nut it was changed last season and was not unusually tight. perhaps i torqued it too tight but that is something i never considered. with the position of the leak so near the turbo intake i'm glad it didn't ingest enough to hydro lock.

seems odd to me that the rotational force used to replace the zinc could loosen the oil cooler end cap. something that was not mentioned in the mack-boring "diesel for dummies" course.

[RobS]

There is a hex nut molded to the body of the components at the zincs so you can hold that when loosening/tightening the zinc to prevent any torque to the unit. I have never had the feeling of even coming remotely close in torque to consider having to put a wrench on that, but it is there and you may have proven that it's worth using regardless..

This pic is the fresh water cooler but the oil cooler is just the same.

[special k]

o.k. so the story is that on sunday afternoon i had no clue as to the seemingly serious problem with my yanmar. monday a.m. i call bayside diesel. 10am i have a mechanic on my boat and early diagnosis. monday afternoon repairs are identified and nearly completed. tuesday with remaining parts inhand (impeller & o-rings) my diesel is complete and ready to go. thursday's scheduled fishing trip is still happening and vacation to block island last week of june thru the holiday is a go!! (i imagined a spoiled vacation)

i first had major nightmares, no knowing what was wrong or how long to get repairs. i am sure that it is rare to have a qualified tech on my boat an hour after the initial phonecall. all repairs done just on my word, no prepayment or credit card info. i'll be out on the salt fishing before the invoice reaches my home. all in all bayside diesel made my high anxiety bearable. (plus no blown turbo)

[special k]

just got a call back from bayside.......

need one more oil change.....still milky

[RobS]

i would have thought that one oil change would not do the trick. It don't take a lot get it milky..

[special k]

especially when we have to suck it out through the dip stick tube.

can't just open the pan and let it drain....

[DougSea]

All in all it sounds like you came through this relatively unscathed and you learned some stuff about diesel combustion AND that you appear to have a great service company! Add one to the experience column!

Glad to hear your fishing and vacation didn't get messed up!

[jleonard]

Awesome. Maybe I'll see you on the Block. Thinking about going over on the 4th