engine vibration

[user 55360]

All, I am having problems with my Mercury 150XL vibrating in clutch ahead, meaning just in gear at low RPMS. I have had this issue since it was new, 1.5 years ago. I believe it is being caused by the prop which keeps loosening up. Factory rep has looked at the prop and reinstalled it to proper torque specs, 100'lbs. But it loosened up again and the vibration came back. Anyone have any ideas? The run out on the shaft is .002 which is well in factory specs.

 

[Andrebass]

Prop not balance
Bent shaft

Can't believe a nylock nut is coming loose.

 

[user 55360]

Prop not balance
Bent shaft

Can't believe a nylock nut is coming loose.

It’s not the shaft. We’ve done a run out and it is only 2 thousandths

 

[Joe Winkler]

I would try another hub insert first then try a different prop. If those aren't the problem then I would gi deaper into it and look at the main drive shaft.

 

[Husker525]

I admittedly do not know if the 150 XL and the 115 Pro XS are similar or different. However, I had a 2020 115 Pro XS that would do the same thing, and was constantly backing off, including the vibration at low forward, and worse in reverse low rpms. I checked run out and it was in spec as well. Mine came with a Merc aluminum prop that had no dings in it. I switched to a SS just for performance, and all my vibration issues and backing off ceased. That told me that the issue was solely in the prop.

Do you have an aluminum prop? Is it possible that it is out of balance? Just my 2 cents worth, as I know how aggravating the nut backing off can be, as well as the vibration.

 

[user 55360]

I admittedly do not know if the 150 XL and the 115 Pro XS are similar or different. However, I had a 2020 115 Pro XS that would do the same thing, and was constantly backing off, including the vibration at low forward, and worse in reverse low rpms. I checked run out and it was in spec as well. Mine came with a Merc aluminum prop that had no dings in it. I switched to a SS just for performance, and all my vibration issues and backing off ceased. That told me that the issue was solely in the prop.

Do you have an aluminum prop? Is it possible that it is out of balance? Just my 2 cents worth, as I know how aggravating the nut backing off can be, as well as the vibration.

So I have different mechanic helping and he believes it is another bad prop. I’m waiting to hear back.

 

[user 55360]

Mercury warrantied the Enertia prop. I run tested it with the tech. The vibration is better damn near gone. I still have to run it for a few hours to see if it loosens again. FYI quick note. There is a tech pub for the flo-torq IV hub that allows for 1/8 play front to back and side to side, which I think is horse.... as does the tech. Is anyone out there running another model prop and have any suggestions?