All of a sudden, dark gray smoke and reduced rpm. ??

No fresh air, an engine will not run on exhaust fumes. The leaking exhaust reduced the amount of fresh air in the engine room.

RickB can figure that out. Can't you Rick?

In this particular case, I am forced to agree with Marin. It sounds too complicated to have a hint from the forum people...sorry!

awpptdt said:

No fresh air, an engine will not run on exhaust fumes. The leaking exhaust reduced the amount of fresh air in the engine room.

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Yep, restricted air flow will cause smoking. I will qualify that by saying I know nothing about MTUs. So, if that is the brand engine, disregard what I said.

Blue Heron--We took it to PP not knowing if it would be on one engine or two. Cranked them up yesterday afternoon and headed west. Ran 2400 RPM on both all the way. Used laser tack to check to see if port was slipping. It wasn't. Monitored temp of tx on both engines at different locations for comparison purposes. Engines ran 170 degrees, the questionable tx was about 6-8 degrees warmer than the starboard tx but both held constant for the hour and a half trip. Got to the dock and no reverse on the questionable tx. Dale, driving from the upper helm said shifter felt funny, try the lower helm. It worked fine, so believe part of the problems is in the shifter linkage from the upper helm. We blocked in the row closest to the office building and next to last in that line, so pretty well protected from seaward wind. Will take a look at the oil in the questionable tx to see if burned or not. If burned believe we have a tx. problem as well as shifter.

Hauled the pontoon this afternoon and will take Dale's shrimpboat up river tomorrow and anchor it.

"and than for 3 hours on the next trip out at 2400rpm with no problems."

How many RPM do you get at full throttle underway?

Water getting into the cylinder usually shows as huge white steam/smoke .

Portuguese said:

RickB can figure that out. Can't you Rick?

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Thanks for the vote of confidence but since I wasn't there I can only guess ... but, my guess is that the decades old rubber elbow finally failed and the cloud of exhaust and water vapor fouled the air filters and created the smokey horror show.

If you are going to use rubber elbows, use high temperature rated silicone so that an otherwise minor raw water issue won't turn into a serious problem before you can deal with it.

FP,

glad you got her hauled out. We hauled out Saturday at Bahia Mar. Good luck!

p

Good luck to you guys in the storm's path----especially those without named storm coverage. Winds around Moonstruck got up to 45 mph with maybe a gust up to 50. Everything is OK with her. Should start polishing the hull tomorrow.

Re the transmission issue.
on the twin Disc 506. The shift is a small stud that sticks up off the tran housing it is sort of a clamp. I had an issue with the tranny slipping. It was that clamp not tight enough. I had someone run the shifter through the gears and made sure it was tight and in the proper position. Fixed.

Is your tranny a Twin Disc?

Sd

Fighterpilot said:

Just check the other air fliter this morning, which I knew was good 4 eingine hours before the debacle. It was covered with black soot as well. Change that too.

Interesting, the only way you can get them out because they fit under the deck with very little clearance is to remove the butterfly nut on top, lift up the housing off the engine, reach in with long pliers and back out the main stem that screws down into the engine block, being careful not to let it fall down into the intake manifold housing, than slide the whole filter sysem out. I wonder if they make an aftermarket k and n type filter adapteer that would work?

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Have you found the exhaust leak?

It will cause the filter to collaps.

SD

" an engine will not run on exhaust fumes"

Might want to advise the EPA , all too many engines have EGR (exhaust gas recirculation) where the engine is forced to eat exhaust by the Air Police.

FF

If any one is buying a boat in Florida with 3208 engines, you might want to hire an engine surveyor who has a phone number that explains his specialty -Bruce Hicks 954-661-3208

My RV 1160 CAT is rated 210hp at 2800rpm.

The 1160 was the industrial daddy to the 3208 , but with real diesel cylinders was too expensive for the 3208 market.

I too worry about 2400 being way to close to constant overload.

That's why I asked what you get on the pin, full throttle. ?????

FF said:

I too worry about 2400 being way to close to constant overload.

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RPM alone doesn't mean an engine is loaded or not, after all the highest rpm you can reach is high idle and that is obtained with no load.

Overload is defined by the power output at a given rpm, look at the propeller curve, not just the tach alone. After all, isn't that what you are doing when you promote the idea of a "cruise prop?"

"RPM alone doesn't mean an engine is loaded or not, after all the highest rpm you can reach is high idle and that is obtained with no load."

That's why I asked for the rpm he pulls at flank underway.

IF he can get to rated 2800 rpm 2400 should be down enough due to the prop curve to not be an overload.

My problem is 3208's are neither strong or powerful and easy to overload.

The cruising prop concept is not for a plaining boat in a big hurry .

It it to rationalize the stoopid sized engines frequently stuck into displacement boats , that are attempting to get better fuel burn , lower noise and a non slobbering engine operation.

FF

Fighterpilot said:

I'm a long way from Seattle. In the panhandle of Florida, but thank you for the contact.

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Don't know if anyone suggested it....but have you tried MESA over the line in AL? Mark is the main guy there....

awpptdt said:

No fresh air, an engine will not run on exhaust fumes.

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Take a look at a "Closed Cycle Diesel" and see how much fresh air it needs.