As we made our way to Annapolis on the Chesapeake, we noticed that our engine revs would occasionally surge REALLY high and then drop back down. Since we were reliant on the engine, we were worried about continuing any further with out fixing the problem. After discussing with a few other cruisers, we decided the filters needed to be changed.
Tim got out his manuals and checked for details online about how to proceed. It was straightforward enough, so he got stuck in. Changing the filters was easy enough but when he went to push fuel though the system, he accidentally introduced air into the high-pressure side of the fuel. In the past someone added a fuel bulb to help bleed air out of the low-pressure side. As Tim was pumping the bulb a crack appeared and he pushed air into the fuel system without realizing it. Dang it. When he started the engine the air was forced into the high-pressure side. At least that’s what we think happened. Since the bulb was an add-on, Tim decided to take it off and connect the hoses directly. He now needed to bleed the high-pressure side to get the air out. Again, all manuals and the Internet were consulted to ensure the correct procedure was followed.
After a couple of frustrating hours he was at a loss. Just then, Craig from Might Fine dropped by to see how it was going – that was Craig’s first mistake, his second was to offer help. I quickly welcomed him aboard and before he knew it, we stuffed him in the “basement” and he was on the job. I went ashore to run some errands and when I returned many hours later, was shocked to see Craig was still in the basement and now both Tim & Craig were frustrated. They had been meticulously following the directions to loosen screws and pump fuel in the specific order needed and were getting nowhere. The engine would not turn over. We sent Craig home, grateful for all his help and decided to leave the project for the night. (Thanks Craig!)
We cleaned up and went into town for our lobster thanksgiving dinner. The next morning we said good-bye to Mar-a Largo and Mighty Fine as they headed further south and we headed for West Marine. Tim had begun to wonder if the fuel bulb was maybe required to get enough fuel pushed through to bleed the air out. We took the dinghy ashore and caught a bus to West Marine for a replacement bulb. About an hour later, we were back at the boat and Tim was back in the engine room trying to bleed the system once more with the new bulb in place. By 11 am he gave up and called a local marina to see if they could send someone to the boat to help us. The folks at Annapolis Harbour Boat Yard came highly recommended on Active Captain and especially by cruisers experiencing issues as they took their boats south, looking to get back on the water quickly. “Ray” (we might have his name incorrect – sorry!) arrived by skiff around 1:30 pm and had the engine running within 10 minutes. There are two screws that are never mentioned in any of the instructions we have for bleeding the high-pressure side and once they were included in the procedure, the engine fired up and the job was done. It cost $100 for someone to come to us, but we learned something new and valuable about the Perkins 4-108.
We were waiting at the Spa Creek Bridge for the two o’clock opening, idling in one place without the need to do donuts. What a relief! Since then, the engine has been running great with no unusual revving. Knock on wood.