Curious what some opinions might be.
My friend has a 30ft sailboat with an electric engine. Engine runs fine, no problems. This weekend we were delivering the boat from one marina to another 40'ish miles away.
When we first undocked, when throttle was applied to leave the slip, the engine revved up for about two seconds, just enough to power the prop to get us out of the slip then died. Foreward power on the throttle did the same. I reversed and put the engine in forward several times with same result. Symptom was like a battery that just died suddenly but kept happening. We limped to another dock with some help. Confused because the batteries are new and fully charged and healthy, I switched swithces back on and off several times thinking maybe it was a dirty contact or that some debris had made its way across a contact. Either this or something had found its way around the prop. In any case, when i came back up and tried it, the engine seemed to work again, so we left and headed out. We motored out a long way and engine worked perfectly.
A few hours into the sail, the winds died down so we decided to motor sail for a while to keep our speed up. All of a sudden there is this nasty grinding noise like metal-on-metal coming from what sounds like the area of the cutlass bearing. Also, the engine revs are becoming erratic, meaning that the prop shaft (observed from inside) spins in a way that it seems like there is some resistance. It cycles between spinning quickly and then slows down some, then spins quickly again, then slows down again like there is some erratic pressure on it.
We are going slow enough that i can pop it in reverse thinking maybe kelp or a bag or something is wrapped in the prop. When I do the grinding noise goes away. I go back into forward and the grinding noise comes back and the erratic motion of the prop comes back. At this point I figure maybe its just from the waves or forces on the prop from underwater. We are still sailing along at three kts or so. Out of curiosity, I put the prop in neutral and let it free wheel and the grinding noise goes away. The electric motor also has a 'regen' ability which allows the prop to freely spin but uses the energy to recharge. I put it in regen mode and the grinding noise is also not present. Thinking the problem is gone, I shift back into forward and a slowly the grinding noise comes back again. At this point im pretty confused but we need the motor now so keep it in forward gear. It never gets any worse but also does not go away. We make it back to the marina with no further issues.
So i'm scratching my head trying to think of culprits that would explain why the grinding sound only appears when in forward gear under load. I was not able to dive on the boat as we got back pretty late and i'm not sure when the new owner will schedule a diver to go check the prop. The new owner is a good friend of the previous owner so i made it clear we need a diver to take a closer look asap.
I confirmed the sound is 100% external to the boat, however i'm not 100% certain it was the cutlass bearing. Thats just my best guess. The boat has a fixed prop so not much to go wrong. My best guesses so far are just two theories. First, possibly a loose or mis-aligned motor mount allowing the engine to put torque on the prop under power in a way that forced the shaft into an awkward angle where it passes through the cutlass bearing. Second, that something had wrapped itself around the prop very close to the forward side of the prop where it enters the cutlass bearing, and when under load pushed up against it creating some friction and drag. I guess the diver will confirm #2 unless its something small that has worked its way into the bearing.
Anyways, any other best guesses i'm missing? This is a real headscratcher.
To add...I have sailed and motored many, many hours and miles on this boat over the past few years and it has performed flawlessly up until now.
My friend has a 30ft sailboat with an electric engine. Engine runs fine, no problems. This weekend we were delivering the boat from one marina to another 40'ish miles away.
When we first undocked, when throttle was applied to leave the slip, the engine revved up for about two seconds, just enough to power the prop to get us out of the slip then died. Foreward power on the throttle did the same. I reversed and put the engine in forward several times with same result. Symptom was like a battery that just died suddenly but kept happening. We limped to another dock with some help. Confused because the batteries are new and fully charged and healthy, I switched swithces back on and off several times thinking maybe it was a dirty contact or that some debris had made its way across a contact. Either this or something had found its way around the prop. In any case, when i came back up and tried it, the engine seemed to work again, so we left and headed out. We motored out a long way and engine worked perfectly.
A few hours into the sail, the winds died down so we decided to motor sail for a while to keep our speed up. All of a sudden there is this nasty grinding noise like metal-on-metal coming from what sounds like the area of the cutlass bearing. Also, the engine revs are becoming erratic, meaning that the prop shaft (observed from inside) spins in a way that it seems like there is some resistance. It cycles between spinning quickly and then slows down some, then spins quickly again, then slows down again like there is some erratic pressure on it.
We are going slow enough that i can pop it in reverse thinking maybe kelp or a bag or something is wrapped in the prop. When I do the grinding noise goes away. I go back into forward and the grinding noise comes back and the erratic motion of the prop comes back. At this point I figure maybe its just from the waves or forces on the prop from underwater. We are still sailing along at three kts or so. Out of curiosity, I put the prop in neutral and let it free wheel and the grinding noise goes away. The electric motor also has a 'regen' ability which allows the prop to freely spin but uses the energy to recharge. I put it in regen mode and the grinding noise is also not present. Thinking the problem is gone, I shift back into forward and a slowly the grinding noise comes back again. At this point im pretty confused but we need the motor now so keep it in forward gear. It never gets any worse but also does not go away. We make it back to the marina with no further issues.
So i'm scratching my head trying to think of culprits that would explain why the grinding sound only appears when in forward gear under load. I was not able to dive on the boat as we got back pretty late and i'm not sure when the new owner will schedule a diver to go check the prop. The new owner is a good friend of the previous owner so i made it clear we need a diver to take a closer look asap.
I confirmed the sound is 100% external to the boat, however i'm not 100% certain it was the cutlass bearing. Thats just my best guess. The boat has a fixed prop so not much to go wrong. My best guesses so far are just two theories. First, possibly a loose or mis-aligned motor mount allowing the engine to put torque on the prop under power in a way that forced the shaft into an awkward angle where it passes through the cutlass bearing. Second, that something had wrapped itself around the prop very close to the forward side of the prop where it enters the cutlass bearing, and when under load pushed up against it creating some friction and drag. I guess the diver will confirm #2 unless its something small that has worked its way into the bearing.
Anyways, any other best guesses i'm missing? This is a real headscratcher.
To add...I have sailed and motored many, many hours and miles on this boat over the past few years and it has performed flawlessly up until now.
