Duckinator
Cadet
- Joined
- Mar 17, 2008
- Messages
- 13
I have a 2015 Suzuki 25 hp. Been very happy with it but the OEM prop is real thin at the tips and easily warped in my swamp. Been running stainless steel on my previous Merc 25s for 30 years so I bought a stainless steel prop for this motor.
I installed it and found it has a terrible knocking/rapping/hammering noise at idle speed in forward or reverse. None in neutral. The noise goes away when RPM is increased. I swapped back and forth with the OEM aluminum prop several times to verify I had it installed correctly. No noise with the aluminum prop.
The prop turns freely by hand without interference. There is clear, clean oil in the lower unit. The propshaft is straight although there is some end play if I wrestle the prop around.
Could this be a backlash issue in the gears in the lower unit that the mass of the heavier stainless steel prop causes them to rattle back and forth upon engine firing? Or something in the prop itself such as splines or hub being loose? incorrect torque on prop nut? out of balance prop?
I am concerned my lower unit has an issue but I don't think I have had any hard hits - nothing more than warping the outer 1/2" of the aluminum prop.
I installed it and found it has a terrible knocking/rapping/hammering noise at idle speed in forward or reverse. None in neutral. The noise goes away when RPM is increased. I swapped back and forth with the OEM aluminum prop several times to verify I had it installed correctly. No noise with the aluminum prop.
The prop turns freely by hand without interference. There is clear, clean oil in the lower unit. The propshaft is straight although there is some end play if I wrestle the prop around.
Could this be a backlash issue in the gears in the lower unit that the mass of the heavier stainless steel prop causes them to rattle back and forth upon engine firing? Or something in the prop itself such as splines or hub being loose? incorrect torque on prop nut? out of balance prop?
I am concerned my lower unit has an issue but I don't think I have had any hard hits - nothing more than warping the outer 1/2" of the aluminum prop.