As my Scottish good friend Rabbie Burns would say “The best laid schemes o’ Mice an’ Men, Gang aft agley”.
The approach to Postcard Inn Marina is a mile + long, idle speed, channel much of which is quite shallow. Alongside the channel, maybe 1-200’ away there were 50 or more speedboats, pontoons etc in the flats with people wading around. Obviously a real party gathering place. At times there was only a foot of water beneath my keel and a few places, less. At one point I felt the boat touch very lightly and very briefly.
This morning, Thurs 3/12, planned to leave around 9 am which would be mid tide and more depth. I was hoping for a long travel day to Miami. Pulled out of the slip and out into the channel. Once past the last channel marker I advanced the throttle and whoa… The port engine responded running up to 2000 rpms but the starboard engine would go above 1200 rpm with vibration above 1000. Discounted fuel as I have a single tank and the fuel filters have just been changed. Discounted trans problem as those filters have just been cleaned, new fluids put in and they were checked, as they are every travel day, and were full. No leaks detected on the new white absorbent pads beneath the engine and trans. The dripless shaft seals which had just been adjusted, were in fact dripless. Most obvious possibility was that I picked up some line/rope yesterday coming in or this morning going out and it wrapped around the starboard prop and shaft.
I turned around and idled back to the marina and pulled into the slip and called a diver. While waiting, I found that I needed to vacate the slip by 2pm as it was reserved for another boat. The diver arrived and told me that there was nothing wrapped around the props or shafts. Best case scenario was that the line had untangled and gotten free. Worst case was that though there were only some minimal nicks on the props, there was evidence of some sand abrasion at the edges so it’s possible that one of the 4 blades was knocked out of line (pitch). Since the props blades are tuned via computer with 1/1000 of an inch, such misalignment would not be visible to the naked eye, especially underwater.
The props, with each blade at a precise angle and cup, act as two big counter rotating port and starboard corkscrews. The cork is the water and the corkscrew propels itself through and pulls the boat with it. Each of the 4 blades per prop must follow precisely the path of its predecessor blade in order to work. As in the case of a drill, try drilling a straight and clean hole with a bit that is malformed and imagine that scenario moving 44,000 pounds through heavy solid water. It was time to do a sea trial and determine which of the two scenarios was correct. So out of the marina I went, down the channel to open ocean and found that the issue remained. So it was time to shut down the use of the starboard propulsion. (Even though I couldn’t feel vibration at 1000 rpm or less, doesn’t mean there wasn’t vibration below and the vibration was being absorbed by bearings and rubber. It’s just not worth loosing a shaft or other expensive parts just to use two engines.)
Knowing that Postcard Inn Marina was full, crew started contacting nearby marina in ever increasing distances. The closest found that had availability was 25 miles away. Then my phone rang. It was the owner of Props & Bottoms, which had dived the boat, asking if the problem had been solved. Advised him “no” and that the nearest marina with a vacancy was Gilberts. He didn’t want to have to dive Gilbert’s as the water was too dirty and had many crocodiles. He said he’d call me back. He found one marina but my draft was too deep for it. But, he said, he had gone to school in NC with the Postcard Inn dockmaster and that he’d talk to him.
Received a call back that Postcard Inn had an opening in the charter fleet section (not as nice) and if I would bring the boat to the fuel dock, they’d help me get into the single vacant charter slip. And so once again I turned around and on one engine limped back to port. Within an hour, the divers were back and pulled the props. I gave them a printout of what the prop specs should be and should hear tomorrow if indeed the starboard prop was a problem. If so, the props should be reinstalled on Saturday. Based though I what I saw of the props on the dock, I seriously doubt that the props were the problem. Whatever – Woohoo. Get to sleep in tomorrow.
Wow. Two trips in one day for a total of 10.9 nautical miles!
Friday morning I got a call from the tech at the prop shop. He was very surprised with the props. To paraphrase, ‘few boats have props with blades that thick. These props are ones you’d normally find on a tug. They aren’t going to bend with a small hit so he doubted the props were my problem. But they hadn’t been sand blasted yet and run on the computer so this was just a heads up that he thought I should look at other sources for the problem.
As busy as it is down here, not even finding an overnight slip within 25 miles, I figured some transient old fart like me calling around for mechanical help wasn’t going to get the time of day. So I enlisted the help of the dive shop owner who, based on charter fishermen’s greetings and comments, seemed to be well respected and I asked Him who I should contact. He gave me a couple names and a recommendation and then he offered to call the guy and ask him to take my call. He also had us drain some diesel fuel from the bottom of the starboard racor filter onto a white clean cloth.
Though the red dyed diesel fuel looked good through the bottom glass (above), unscrewing the bolt at the bottom allowed some fuel to drain on the white towel and the red fuel had numerous eraser sized black spots that were a bit gritty. Undoubtedly one or more injectors (one injector for each cylinder) are fouled and though the computer would ship more fuel to the remaining cylinders it wouldn’t be enough to replace the power lost by the fouled cylinder(s).
Diesel fuel is literally food for microbes which live their lives in the fuel, multiply and die. The engines hadn’t run in over 2 months so there were probably many dead microbes settled to the bottom of the tank. Those were probably stirred up by the addition of 400 gal of fuel added Weds morning (I’m assuming that fuel was fresh) and then further stirred up by the rougher morning sea conditions. While running at speed Weds, these ‘carcasses’ were probably forced through the system but then clogged after the engines were shut down Weds night causing the problem Thurs morning. This hasn’t been proved yet but is my best guess based on what I saw.
The mechanic stopped by late Fri afternoon and confirmed it as his best guess as well. He will be back and all the filters will be changed and injectors checked and cleaned as needed (both engines). I will keep my spare set of filters on hand in case another change is needed while underway. Hope to be ready to go early next week. Hope the nice weather and calm seas hang around.
Meanwhile the prop tech has called and the props are done. Some very minor welds, a little tweak and a polishing – definitely NOT the problem. Divers should reinstall the props on Saturday.
Saturday evening. The prop shop and diver came mid afternoon and in about 1.5 hours the shiny polished props are now re installed under the boat. I’d sure hate to have to horse around 150# props down from the dock to the harbor bottom and then lift each up to the shaft, line it up so the key bar lines up in the shaft and prop channel and then install the 2 big nuts that hold it together. It is a precision install even when the boat is hauled on land to say nothing of underwater.
CJ, the mechanic called and confirmed that he’d arrive Monday morning and that he had all the requisite filters and equipment. Will be paying close attention in the event it might be needed to do the filter changes and re-priming while underway somewhere else.
Not a bad place to hang out while waiting. The marina is smallish – maybe two dozen slips for the charter fishing and dive boat fleet and 15 or so slips for pleasure boats. Hotel, pool, a really nice Italian restaurant, a large tiki bar, an elevated raw bar, lots of scattered out door seating areas with gas fire pits and a clothing boutique. Across the Overseas Hwy channel bridge within easy walking distance are two more large restaurants. Put in an order to Publix to supplement the groceries on board and for the more perishable fruit etc. plus another 5 cases on bottled water to be delivered via Instacart. That was Friday morning and the soonest it could be filled was Friday @10 pm or Saturday noon. Opted for the latter as 10 pm would be well past my bedtime😴😴😴
Monday 3/16. The mechanics came this morning as promised. They are finding evidence of contaminated fuel pretty much throughout the stbd engine. Apparently the filters on the port engine did a better on. Not sure why. Crew walked a mile to West Marine this morning and bought all 8 of their Racor filters. I already have 2 spares and the mechanics will be installing 2 fresh ones from there supply so I’ll have enough for 5 filter changes once underway. The filters that came out were pretty black.
The injectors on the stbd engine needed attention as well. So they were pulled, taken to the shop, bathed twice and all cleaned up and tested for pressure and spray. All A-OK. They arrived back around 5pm and are being reinstalled.
One of the hindrances to me changing out the filters has been the engines losing their prime when changing filters. The last time they were changed it was by a Cummins authorized service center. After installing the new filters, they could not restart the engines.
Schematically, the fuel exits from near the bottom of the fuel tank and flows to the Racor filters which are located very near the floor of the engine room. From there, the fuel is taken by the fuel pump to a secondary filter on the engine and then all the way to the top of the engines where the fuel is injected into the cylinders and exploded. So the fuel flows from low to high and the elevation distance probably exceeds 4’. So the problem is when you open the Racor canister and remove the filter, the fuel in the lines, by gravity, flow down and the lines are filled with air or vacuum rather than diesel. When that happens, the engines won’t start and the system needs to be re-primed.
I don’t have a clue how to do that. What I’ve read is that there is a little finger pump somewhere which when you push, forces fuel up the lines to the fuel pump. The fuel pump takes over but the non-compressible air in the lines between the fuel pump and injector makes flow to the cylinders totally or nearly impossible. Engine won’t run. You need to slightly loosen an injector, crank the starter until the air is pushed out by fuel, retighten the injector and repeat individually for the remaining injectors till the engine starts. Repeat for second engine.
The mechanic has now installed a simple shutoff valve between the Racors and the fuel lines up to the engines. Want to change filters? Close the shutoff so the diesel won’t flow by gravity back down, open the canister, pull the old filter, install the new trying not to displace any fuel in the canister. After being sure the canister is still full, close the canister, open the shutoff valve and start the engines.
Mechanic is telling me that as I head north I should again change filters in St Augustine, then again in Savannah, maybe again in Myrtle Beach etc until it’s obvious with the white rag and clean filter that the fuel has been cleaned (it’s called polishing the fuel).
Far more fuel is pumped through the filters and into the engine than is needed and the excess fuel not needed for combustion is returned via another line back to the fuel tank. In this way, cycling fuel over and over through the series of filters, the fuel is polished/cleaned. You can also hire companies to come and run lines from your tank to their equipment and they will polish the fuel.
Eight pm Monday and the job is finished. The mechanic will be back in the morning and we’ll do a sea trial to make sure all is well. Then, after a pump out, I can resume heading out to points North. Hoping when I am able to get out, that the Coast Guard doesn’t close ports to pleasure boating!