SRQ
Registered
I've read all the posts and I'll throw in my .02 cents as I've been an outboard mechanic for thirty plus years.
By reading in between the lines it sounds like you have run across the proverbial "parts changer". They replaced the flywheel (and most likely the stator) because they assumed the end result of damage was by the flywheel magnets coming loose, but they didn't take it to the next step by determing 'why'. Way too many small boat repair shops assume too quickly and don't take into account other probable causes.
It sounds like to me your upper bearing has been failing all along. This could have been caused by a number of reasons: water intrusion, bearing fretting, fractured main journal, improper propellor selection, out of balance harmonics and the list goes on. An experienced mechanic would have just grabbed the cranckshaft and shook it, and noticed the excessive radial play in the shaft.(This is what caused the interference between the flywheel and the stator in the first place) The mechanic surely would have noticed something funny going on while trying to torque the flywheel nut down. Unfortunately commission based mechanics are notorious for flying through diagnostics and missing the real source of the problem. Judging by the amount of time you drove the boat in between repairs, I would almost bet a compression check would have shown this problem at the time of purchase. The bearings, or fragments of bearings most likely would have done some damage to the cylinders at that time and would shown a drop in compression on the #1 cylinder. Maybe thats one of the reasons the owner wanted to get rid of the boat in the first place and was so happy to pay for half the repairs (but this is only speculation)
Anyway, good luck with your motor repair and the search for a good technician. A good mechanic is worth his/her weight in gold.
WB
By reading in between the lines it sounds like you have run across the proverbial "parts changer". They replaced the flywheel (and most likely the stator) because they assumed the end result of damage was by the flywheel magnets coming loose, but they didn't take it to the next step by determing 'why'. Way too many small boat repair shops assume too quickly and don't take into account other probable causes.
It sounds like to me your upper bearing has been failing all along. This could have been caused by a number of reasons: water intrusion, bearing fretting, fractured main journal, improper propellor selection, out of balance harmonics and the list goes on. An experienced mechanic would have just grabbed the cranckshaft and shook it, and noticed the excessive radial play in the shaft.(This is what caused the interference between the flywheel and the stator in the first place) The mechanic surely would have noticed something funny going on while trying to torque the flywheel nut down. Unfortunately commission based mechanics are notorious for flying through diagnostics and missing the real source of the problem. Judging by the amount of time you drove the boat in between repairs, I would almost bet a compression check would have shown this problem at the time of purchase. The bearings, or fragments of bearings most likely would have done some damage to the cylinders at that time and would shown a drop in compression on the #1 cylinder. Maybe thats one of the reasons the owner wanted to get rid of the boat in the first place and was so happy to pay for half the repairs (but this is only speculation)
Anyway, good luck with your motor repair and the search for a good technician. A good mechanic is worth his/her weight in gold.
WB