Vibration at 2000RPM

[Boss Hawg]

1987 Johnson 70hp
I feel a distink vibration in my motor at about 2000rpm's but no other time Lower or higher it feels & runs fine----
Cause to worry?

 

[kenmyfam]

Re: Vibration at 2000RPM

Is the motor tight to the transom and the transom in good shape (sound)

 

[Boss Hawg]

Re: Vibration at 2000RPM

Is the motor tight to the transom and the transom in good shape (sound)

Yes to both-

 

[etex driller]

Re: Vibration at 2000RPM

Could be in prop balance boss its like a tire or drive shaft and may be slightly off where you get vibes at one certain speed or rpm I bought a new turbo prop once that did similar its worth checking.great prop shop in longview. Not familiar with any in your neck of the woods.

 

[jonesg]

Re: Vibration at 2000RPM

you could try removing the prop and re-install it 90 degs different from where it is now, it could be a dynamic balance issue.

check for fishing line on the shaft while its off, clean and apply new grease.

 

[Boss Hawg]

Re: Vibration at 2000RPM

Prop sounds likely- it's far from new or perfect, no bends or cracks but a lot of small chips & edges are pretty chewed up-
First i'll try removing the prop and re-install it 90 degs different
Thanks