Yamaha F115 lower unit clatter

[2230]

I have a 2001 F115 that has a little over 1,000 hours on it. When I run it with muffs on in my driveway I have a fairly loud clatter coming from the lower unit at low RPM when in gear. If I rev it up a little the noise goes away. When the boat is in the water I can't hear the clatter at all at any rpm. I've verified it's not the prop. Is this something to be concerned about? Any thoughts on what's wrong with it, if anything?

Any thoughts and advice would be greatly appreciated!!!!

 

[99yam40]

Re: Yamaha F115 lower unit clatter

Is this one of those motors that need to have the drive shaft lifted up when setting the collar above the water pump to keep it from making noise at idle?
Just something to look in to.

 

[rodbolt]

Re: Yamaha F115 lower unit clatter

its kinda normal. especially if you have a stainless prop.
its also kinda stupid to have it in gear on the muffs with the prop on.
it can be very dangerous.
if it works fine in the water why worry what it does on the flusher?

 

[2230]

Re: Yamaha F115 lower unit clatter

I do have a stainless ballistic prop on it. I noticed the noise last spring and it made it through the summer without any problem. It is not quite as loud if I put my aluminum prop on. So you don't think there's anything I need to have repaired?

 

[rodbolt]

Re: Yamaha F115 lower unit clatter

unless someone has installed the lock coller and retainer incorrectly its rather normal to have some chatter out of the water due to crankshaft acceleration and deceleration between firing strokes.
propshaft tries to remain constant so the shaft clutch starts banging.
incorrectly installed retainer assy will cause low speed knock while in gear in the water.
some props are worse than others for chatter.
if you have ever seen some one eaten by a prop on the flusher you will remove yours if you have need to shift gears while running on the flusher.
I cant really think of a reason to on your engine.

 

[2230]

Re: Yamaha F115 lower unit clatter

I've had the motor since new and the lower unit has never been apart, so I'm going to assume I'm OK. Thanks for the advice!

 

[rodbolt]

Re: Yamaha F115 lower unit clatter

well if its a salt water use engine run it till it dies as its quite possible it wont come apart now.
cause what your saying is it hasnt had a water pump in 9 years.
you have to remove the lock collar and retainer to change the water pump.