I recently purchased a pontoon boat and on day #3 my motor died, I'm hoping to get some help from the community with correctly diagnosing and fixing the problem.
The motor - 1999 Yamaha 80hp four stroke (F80TLRX).
The problem - 30A fuse is blown, and when it's replaced the rectifier starts overheating (burning and smoking).
What happened - I was cruising along and started to increase throttle, but suddenly started losing power. With a minute or two the engine died, and I had no power to the tilt/trim motor (from either remote or engine side) or starter. One clue, or perhaps red herring, is that shortly before this occurred I tried turning on the fish finder. It didn't power up, which was odd, as it had worked previously before this cruise. Another clue/red herring, is that I found the electrical cable to the masthead light was under stress because of a broken seat cover.
Attempted solutions - My first step was checking the fuses, and the 30A fuse was blown. As mentioned the motor started smoking badly and emitting a burning smell when I replaced the fuse, which I confirmed was from the rectifier after removing some covers. I removed the in-line fuse connecting the fish finder, just in case that was causing a problem, and addressed the masthead light cable, but this didn't resolve anything. The battery is in good shape and the connections are clean and tight, and after inspection of the motor I can't find any loose/broken/chafed wires that might be the problem.
My first inclination is to just replace the rectifier, though if something is causing that to burn up I might just end up frying another one. Any suggestions for how to correctly identify and isolate the root cause would be greatly appreciated before I invest money in parts or a professional marine mechanic. (I may go with the latter in any case just to be on the safe side.) I'm also curious if disconnecting the rectifier might let me start and run the motor, knowing my battery won't be getting charged and some instrumentation won't work.
Thanks in advance for any help offered. If anyone knows where I can find a repair manual for this motor, that would also be appreciated.
The motor - 1999 Yamaha 80hp four stroke (F80TLRX).
The problem - 30A fuse is blown, and when it's replaced the rectifier starts overheating (burning and smoking).
What happened - I was cruising along and started to increase throttle, but suddenly started losing power. With a minute or two the engine died, and I had no power to the tilt/trim motor (from either remote or engine side) or starter. One clue, or perhaps red herring, is that shortly before this occurred I tried turning on the fish finder. It didn't power up, which was odd, as it had worked previously before this cruise. Another clue/red herring, is that I found the electrical cable to the masthead light was under stress because of a broken seat cover.
Attempted solutions - My first step was checking the fuses, and the 30A fuse was blown. As mentioned the motor started smoking badly and emitting a burning smell when I replaced the fuse, which I confirmed was from the rectifier after removing some covers. I removed the in-line fuse connecting the fish finder, just in case that was causing a problem, and addressed the masthead light cable, but this didn't resolve anything. The battery is in good shape and the connections are clean and tight, and after inspection of the motor I can't find any loose/broken/chafed wires that might be the problem.
My first inclination is to just replace the rectifier, though if something is causing that to burn up I might just end up frying another one. Any suggestions for how to correctly identify and isolate the root cause would be greatly appreciated before I invest money in parts or a professional marine mechanic. (I may go with the latter in any case just to be on the safe side.) I'm also curious if disconnecting the rectifier might let me start and run the motor, knowing my battery won't be getting charged and some instrumentation won't work.
Thanks in advance for any help offered. If anyone knows where I can find a repair manual for this motor, that would also be appreciated.