Low RPM Squeak on Alumimun Boat - Johnson 15 hp Outboard

[SacFisher]

I have an older Gregor 15' aluminum boat with a Johnson 15hp 4 stroke. I recently replaced the prop with a lower pitch. Now it is making a squeak / squealing sound just above idle. It does not make the noise at idle or higher rpms. I added 1/2 inch of rubber under the motor mount but that did not help. It is difficult to locate the source - sounds like a metal to metal squeak from the lower unit, but I also suspect it could be a boat vibration. Any suggestions? Thanks

 

[BF]

Re: Low RPM Squeak on Alumimun Boat - Johnson 15 hp Outboard

I had an older motor that did that.. on mine, the squeak/rattle/rubbing sound went away if I turned the motor in either direction... turned out it was the spring for the tilt lock rubbing somewhere on the mid-section just when the motor was pointed straight ahead. Some fine adjustment (prybar used to slightly bend one side of the spring mounting bracket to increase the clearance a bit) solved the problem. Maybe something to check...

 

[robert graham]

Re: Low RPM Squeak on Alumimun Boat - Johnson 15 hp Outboard

I have an 18' Aluminum jon boat and it had squeaks and vibrations everywhere...I took a tube of silicone rubber and sorta caulked around wherever the metal pieces touched/vibrated and finally got it quiet. Maybe give it a try!