Johnson 15 HP low RPM whine under load

Knife

Recruit
Joined
Aug 29, 2010
Messages
2
New to boating.
Equipment: J15REOD ('95 Johnson 15 HP pull start) less than 15 hours on the motor, water pump recently rebuilt as a precaution. Stock prop 9.5x12.5. Pushing a 1648 Jon boat.
Symptoms: High pitched whine at low RPM in forward only. Does not occur in neutral or reverse and goes away at higher RPM's but returns when I throttle down. Do not notice any new/worse vibration.
History: Second day on the water I hit something hard enough to knock a chunk out of the prop. Since they no longer make the stock prop, I replaced it with a 9.25x11 stainless. At this time I also added a bow mounted trolling motor and two deep cycle batteries. Noticeable loss of speed but everything seemed okay for a few weekends of fishing.
Found a dusty but unused 9.5x12.5 prop at a local repair shop and put it on. As soon as I started to go forward, I noticed the whine. Searching the internet all I'm finding are references to cam belts, fly wheels, and vacuum leaks, but I am concerned that it is a bearing or gear in the lower unit, although I cannot pinpoint where it comes from while on the water. I intend to put the 9.25x11 back on to try it as soon as I can. But I'm afraid I'm risking further damage.
Does this sound like a bearing or gear? If so, can they be replaced individually? Or will I have to rebuild the entire lower unit?

I appreciate any advice you all may have.
Knife
 

Knife

Recruit
Joined
Aug 29, 2010
Messages
2
Re: Johnson 15 HP low RPM whine under load

I put the 9.25 x 11 prop back on and the whine was gone. So I am guessing that it is not wise to run the faster prop. However it does seem to be coming from the top of the motor.

Knife
 

222

Recruit
Joined
Nov 15, 2010
Messages
1
Re: Johnson 15 HP low RPM whine under load

Knife,

I lost my prop and am looking for a 9.5x12.5 prop for
my 15 HP Evenrude and 8' Glen-L Tiny Titan hydro.
Is you prop for sale?

No Wake
 
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