Pedal Boat Crank Bushings

[Handy Johnny]

I have a Sun Dolphin pedal boat with oil impregnated crank bushings. After a couple of hours use the cranks start a rubbing noise. Has anyone found a suitable oil for supplementing the original oil? My understanding is that synthetic oils are used, but I want to get the right viscosity, etc. Any other suggestions? I have installed new bushings, but the problem persists. I tried marine grease with the old bushings, but that lasts about 2 hours and requires disassembly to reapply.

 

[Grub54891]

If the shaft is scoured up, it'll never quiet down. Are you sure it's not the petals themselves? The bushings you installed have oil impregnated right into the bushing itself, it should be ok if the shaft is ok. If the crank is sliding side to side to much it could be the problem also. On my paddleboat, it has side thrust washers to hold it in place. Let us know how it goes.

 

[Handy Johnny]

The boat was bought used. The cranks look pretty good, but not perfect. I hate the thought of having to buy new cranks. The groaning noise only came after a few hours use (and persists). The noise is definitely in the bearings. I have tried adding thrust washers, but that didn't seem to help.

 

[airshot]

Part of the problem is the fact that it is a plastic boat.., plastic grows and shrinks under heat from use and from the sun. Had a similar problem with one I owned some years back. No matter what I did the rubbing sound came and went, but got worse in the heat. I used some aerosol spray lube which was supposed to be environmentally safe, while it helped it did not cure the problem as it needed to be applied frequently. I finally sold it and moved to a small jon boat with an electric motor. The good quality pedal boats with aluminum pontoons don't seem to have issues, as they are of a much better quality but look at their price tags and you will see why!