Yamaha F100 Prop chatter?

[TeamNHCBK]

Motor is a 2001 Yamaha F100.

The engine itself runs like a top, zero issues with that I believe. I just installed a brand new stock Yamaha 13.25X17 aluminum prop, as well as the spacer, bushing and castle nut on the prop shaft. I have a whine, not sure if you can hear it in the video, from 1000-1500RPM, it goes away after 1500RPM. But since changing the prop I now have this chatter all the way to 5500RPM, doesn't appear to go away. Performance of the motor doesn't seemed hindered at all. Still can get to max RPM, cruise at same speed, etc.

Ran it today off the trailer with the old prop and still had the same chatter. Not sure what it is at this point. I am purchasing a new drive shaft bushing and will be replacing it. I don't believe it'd make that clicking noise though, it'll help with the whine I'm sure. Bent prop shaft or drive shaft maybe?

Any help on what this noise may be? Thanks in advance.

Video Link: https://youtu.be/DwMGPG-qoQs

 

[99yam40]

might be preignition due to bad gas(low octane)
that can be bad on pistons/motor

 

[TeamNHCBK]

might be preignition due to bad gas(low octane)
that can be bad on pistons/motor

Would this preignition make the clicking sound come from the midsection or down? The sound is 100% not coming from the engine. It's from the midsection down somewhere.

I'm going to get the "GREASE WR NO.2" Yamaha recommends to apply on the splines and where the driveshaft goes through the driveshaft bushing just above the water pump.

Question, I just redid the water pump. Could I have messed something up? Not sure how or what. I'm at a loss at this point with the noise.

Thanks for the help.

 

[robert graham]

Are you dead sure you're not just imagining this noise?....Outboards can tend to make noises....

 

[dingbat]

https://forums.iboats.com/forum/eng...ha-suzuki-outboards/270498-lower-unit-chatter

 

[TeamNHCBK]

I am 100% not imagining the noise. Haha. I've had at least 6 different people come and listen to it. It's certainly a clicking and it's goes up and down with RPMs.

Dingbat, while I do have that low RPM chatter, which I have learn probably has something to do with with the hub of the prop, this noise is different. From what I've gathered from the service manual, my year out board did not have the lock ring and collar that is the common issue to the Yamaha prop chatter.

Thanks for the replies.

 

[dingbat]

I am 100% not imagining the noise. Haha. I've had at least 6 different people come and listen to it. It's certainly a clicking and it's goes up and down with RPMs.

Dingbat, while I do have that low RPM chatter, which I have learn probably has something to do with with the hub of the prop, this noise is different. From what I've gathered from the service manual, my year out board did not have the lock ring and collar that is the common issue to the Yamaha prop chatter.

Thanks for the replies.

I wouldn’t be so quick to count it out.

I run an Evinrude 2 stroke. No history of prop chatter whatsoever with this motor.

Always ran solid hub props up til now. Went to a flo-torq hub and now have chatter. Pretty annoying given how much I troll.

Put old prop on it goes away. 100% the product of the prop.

 

[TeamNHCBK]

I bought a stock OEM prop and have the chatter and clicking. My old prop is a Michigan Wheel Vortex with the XHS hub and get the same chatter and clicking. Also, most of the famous Yamaha prop chatter is low RPM and goes away with increased RPMs. This clicking noise continues throughout the RPM range. I guess you could be right, I just don't know.

 

[dingbat]

I bought a stock OEM prop and have the chatter and clicking. My old prop is a Michigan Wheel Vortex with the XHS hub and get the same chatter and clicking. Also, most of the famous Yamaha prop chatter is low RPM and goes away with increased RPMs. This clicking noise continues throughout the RPM range. I guess you could be right, I just don't know.

I guess the real test it to see if the noise goes away when you put the old prop back on.

The sound of my motor, both on the hose and in the water, changed drastically when I changed props. Both props are stainless, but the new prop is probably half the weight (Mercury X7 Alloy) and the outer hub is much longer and larger diameter. My big ole "throaty" 6 cylinder 2 stroke is now much higher pitched with a metallic ring to it.

Would not have picked my motor out of a line up in a blinded test...

 

[TeamNHCBK]

The noise does not go away with the old prop unfortunately. I'm going to take apart the water pump, see if I did something wrong. I really don't know what else to do. I guess pulling apart the lower unit would be next.