I'm a first time poster. If this is in the wrong place please set me straight.
I am the 2nd Owner of a 2003 Hunter 356.
Yanmar 3GM30(F) with KMP2 Transmission (2.62 ratio)
Cosmetically the boat was very well maintained. Mechanically I've had a lot of work. I had the boat surveyed. The surveyor said to have the engine alinement checked, among many other things. I'll focus on this issue.
I do my own work and am very capable.
This is a fresh water boat and there is virtually no rust or corrosion on any metal parts.
I removed the 4 bolts from the prop flange where it connects to the transmission. I found the flange very loose on the shaft, the key had been chewed up and gone. The flange was chewed up. After removing the two set screws the flange fell off in my hand. The set screws had augured out large detents in the shaft. At least it was easy to get apart.
I removed the prop shaft and flange and cutlass bearing (it was also loose). I took everything, including the cutlass bearing skeg, to a reputable marine machine shop. They put the prop in the pitch blocks, polished and balanced the propeller. The Propeller Shaft was bent a couple thousands out of spec and was successfully straightened. A new cutlass bearing was fitted and pressed into the skeg. A new flange and key were fitted and faced. I also purchased new zincs and packing material.
The surveyor recommended new motor mounts so I purchased them as well. I got the right ones for front and rear mounts. I adjusted the new mounts as close to the height of the old mounts as I could and put everything back in as close to where they were as I could..
I reinstalled everything. The prop shaft is very near the center of its movement range in the through hull fitting. All the original shims under the mounts are in the right place. Got out my feeler gages and went about aligning the transmission flange to the propeller shaft flange. It was waaaay out! After much back and forth I got the vertical alinement down to about .002". But the side to side wasn't even close, it was off by 1/4" or more. I checked everything I could think of. I had the yard service manager look and he just scratched his head. It looks like it was never right. Perhaps that's why the flange was so chewed up. So I removed the engine mounts and elongated holes where they mount to the stringers. This allowed me, with a lot of effort, to get the engine aligned to about .004" side to side. But the rubber mounts are distorted and not sitting square on top of their bases. It appears the holes in the stringers where the mounts are bolted to the boat hull are not in the correct spot. Its like the engine is twisted. The port side a little forward of the starboard side. I don't know what is square in the boat to measure from.
So this is my dilemma. I've read many forums and posts and all make it seem like getting the engine alinement right is just a matter of patients and back and forth on the mounting adjustments. I've never seen anyone say the factory mounted the engine cockeyed. I feel my next step is to unbolt the motor mounts from the hull. Get the engine and prop shaft aligned by allowing the motor mounts to side around and mark new holes to drill in the stringers then run the lag screws in with the mounts in a new position. I'm guessing one side may be 1/4" or so forward or aft from the original holes.
Is it likely the factory made an error? Or should I look for something I may have done? The new motor mounts are in the same orientation as the original mounts.
I am the 2nd Owner of a 2003 Hunter 356.
Yanmar 3GM30(F) with KMP2 Transmission (2.62 ratio)
Cosmetically the boat was very well maintained. Mechanically I've had a lot of work. I had the boat surveyed. The surveyor said to have the engine alinement checked, among many other things. I'll focus on this issue.
I do my own work and am very capable.
This is a fresh water boat and there is virtually no rust or corrosion on any metal parts.
I removed the 4 bolts from the prop flange where it connects to the transmission. I found the flange very loose on the shaft, the key had been chewed up and gone. The flange was chewed up. After removing the two set screws the flange fell off in my hand. The set screws had augured out large detents in the shaft. At least it was easy to get apart.
I removed the prop shaft and flange and cutlass bearing (it was also loose). I took everything, including the cutlass bearing skeg, to a reputable marine machine shop. They put the prop in the pitch blocks, polished and balanced the propeller. The Propeller Shaft was bent a couple thousands out of spec and was successfully straightened. A new cutlass bearing was fitted and pressed into the skeg. A new flange and key were fitted and faced. I also purchased new zincs and packing material.
The surveyor recommended new motor mounts so I purchased them as well. I got the right ones for front and rear mounts. I adjusted the new mounts as close to the height of the old mounts as I could and put everything back in as close to where they were as I could..
I reinstalled everything. The prop shaft is very near the center of its movement range in the through hull fitting. All the original shims under the mounts are in the right place. Got out my feeler gages and went about aligning the transmission flange to the propeller shaft flange. It was waaaay out! After much back and forth I got the vertical alinement down to about .002". But the side to side wasn't even close, it was off by 1/4" or more. I checked everything I could think of. I had the yard service manager look and he just scratched his head. It looks like it was never right. Perhaps that's why the flange was so chewed up. So I removed the engine mounts and elongated holes where they mount to the stringers. This allowed me, with a lot of effort, to get the engine aligned to about .004" side to side. But the rubber mounts are distorted and not sitting square on top of their bases. It appears the holes in the stringers where the mounts are bolted to the boat hull are not in the correct spot. Its like the engine is twisted. The port side a little forward of the starboard side. I don't know what is square in the boat to measure from.
So this is my dilemma. I've read many forums and posts and all make it seem like getting the engine alinement right is just a matter of patients and back and forth on the mounting adjustments. I've never seen anyone say the factory mounted the engine cockeyed. I feel my next step is to unbolt the motor mounts from the hull. Get the engine and prop shaft aligned by allowing the motor mounts to side around and mark new holes to drill in the stringers then run the lag screws in with the mounts in a new position. I'm guessing one side may be 1/4" or so forward or aft from the original holes.
Is it likely the factory made an error? Or should I look for something I may have done? The new motor mounts are in the same orientation as the original mounts.