May have BIG Problems???

[Kevin]

Hey Guys

 

[red coles]

sectionalize

Hello Kevin: This is what you have to do. Disconnect the shaft at coupling and see which way the bind is.Go from there. Yes prop is very adjustable by a competent shop and could rid you of the vibration with balancing. You have to think about the reason for wanting to change the prop specs. Do you get good speed at a reasonable rpm, is the motor lugging? these would be the things to look for before deciding to adj. the prop.  Good luck red

 

[Bob Uehlein]

Prop

The wrong prop pitch will hinder performance but should not cause vibration. With shaft uncoupled from engine, I'd look for cause of shaft not rotataing freely. Start by opening up stuffing box, removing old stuffing and replacing. If that doesn't help, I'd change the cutlass bearing. Wet down the cutlass bearing before rotating shaft, when in the water it is lubricated by water. Your prop could be bent or not properly balanced or the whole assembly could be out of alignment. Do not try to align while the boat is out of the water.

 

[Kevin L. Woody]

check all shaft contact points

Hello Kevin,In neutral you should be able to rotate the propeller and shaft with little force. Even though the shaft bearing is showing no signs of wear you should make sure that the shaft is running true through it. Could the shaft be off set with the bearing creating a bind. If it where me and I wanted to fix this potential HP robbing item, I would remove the shaft bearing and see if the shaft then rotates freely. If it is found that it is still tight I would loosen or remove the current stuffing box to see if it is causing the bind. If that does not work remove the shaft coupling from the transmission coupling and see if you can turn the trans by hand. If not sounds like a trans problem. Anyone of the above items could very easily cause additional load to the engine not allowing it to produce all of the needed HP. I would not re-pitch the prop yet. Until you find what is causing the bind, increasing the pitch, which increases the engine load, could potently increase our speed/power problem. Hope this all helps. Kevin

 

[Kevin]

This is what I found, so far...

It looks like the shaft is binding at the cutlass. Looking fore to aft, the shaft appears to be slightly more compressed on the starboard side on the bearing as it enters and more compressed on the port side as it exits the strut. Also, where the shaft exits the log, the shaft looks polished on one side. Humm, must be rubbing there. That will come out in the morning. A local shop will cut a new one for $150.00. Finally, I took the prop to a local shop and the fella nearly refused to talk to me unless I agreed that I would not ask him to "twist the hell outa that prop!" He said that he has had far too many "sailors" requesting this only to return wanting the prop returned to its orginal shape. He did find the following problems; one blade was @9.3 inches, the next was @9.5, the next was @ 9.9 inches. He heated and pulled the prop to a 13x10.25, sandblasted, and polished for $25. Is this a good thing?Thankx for all of your comments. I'll let you know what else I find.