I have a 1966 24ft Cabin cruiser, very heavy boat compared to newer boat construction. It has an GM inline 6 250ci 160hp, with a pre-alpha drive, 1.65 gear ratio. When I first bought the boat, I could not get the thing to plane nor get it to the appropriate RPM in the water, it had a 19 pitch prop on it. out of the water you can make the RPMS scream. I was told that I was way over pitch. So I had the outrdrive rebuilt completely, new belows, gimbal bearing, shift cable, all that. Compression is good, yada yada. I did some research and came to the conclusion that a boat that heavy with that motor should be pitched around 15p. So I have a 3 blade 15X15 now. Purchased a new hub kit, one of the newer styles where you slide the thrust washer on first, pop the plastic hub in the prop, slide the castle piece into the plastic hub, install the retainer tab ring, and screw down the nut. Well, when I screw the nut down it purhes the prop into the drive, the prop tightens up and won't spin. In order to let the prop spin I have to back the nut off and until the prop spins, then push the metal pins down around the castle piece. This leaves the nut loose feeling but the flat metal ring pieces keep it from loosing any further. But the nut is turnable by hand. I took my chances and put it on the water. It did move more efficiently at first, still would not plane..but was faster with the lower pitch.
After a few days of running her, I check the prop and the nut was almost off, the retainer ring was almost off, and so was the prop. Before this I noticed less speed and I could feel the prop wobbling. Thats why I stopped.
Can someone give me advice on the following questions:
1. Whay does the prop tighten up when I tighten up the prop nut with normal torque specs, to the point that when the nut is at its proper torque, the prop is unmovable? And the back of the prop grinds against the drive? Also, I found weird, the shaft nut that came with the hub kit would not fit. All the hub kits had the finner threads, my prop shaft has the big huge threads. I had to go to home depot to find a bolt that would work on the prop shaft.
2. Why am I still having issues planeing? I cant get WOT in the water. When I have someone physically go to the carb and open it all the way up while on the water it back fires and dies? Should I go with a lower pitch? 13 or so? Seems really low?
3. Could my engine just be tired?
Any help is greatly appreciated. FYI - new throttle and shift cables all around. I went through adjusting the shift cables, shift great, have not done much adjustment on the throttle cable because it will WOT out of water....and in the water it wont even with someone directly opening up the carb at the carb by hand not even using the cable?
Thanks!
After a few days of running her, I check the prop and the nut was almost off, the retainer ring was almost off, and so was the prop. Before this I noticed less speed and I could feel the prop wobbling. Thats why I stopped.
Can someone give me advice on the following questions:
1. Whay does the prop tighten up when I tighten up the prop nut with normal torque specs, to the point that when the nut is at its proper torque, the prop is unmovable? And the back of the prop grinds against the drive? Also, I found weird, the shaft nut that came with the hub kit would not fit. All the hub kits had the finner threads, my prop shaft has the big huge threads. I had to go to home depot to find a bolt that would work on the prop shaft.
2. Why am I still having issues planeing? I cant get WOT in the water. When I have someone physically go to the carb and open it all the way up while on the water it back fires and dies? Should I go with a lower pitch? 13 or so? Seems really low?
3. Could my engine just be tired?
Any help is greatly appreciated. FYI - new throttle and shift cables all around. I went through adjusting the shift cables, shift great, have not done much adjustment on the throttle cable because it will WOT out of water....and in the water it wont even with someone directly opening up the carb at the carb by hand not even using the cable?
Thanks!
