Excessive vibration

[claude wistaff]

I have a '05 merc. opti. 75hp, when you put it in gear there's excessive vibration & clunking sounds at idle speed, but once you increase, normal.
I had a black diamond prop. 19"p & bought a Trophy plus, same pitch, & the vibration & noise became louder.
(This motor was a "end of lease" so it has many hrs.
Any info. would be appreciated
Thx

 

[claude wistaff]

Re: Excessive vibration

Seems I've found the answer thru other web sites.
I'm using the flo-torq II hub, I should be using the flo-torq III since it has the split hub, which absorb the shock of the gear shifting, low idle & heavier prop.
fyi.

 

[Texasmark]

Re: Excessive vibration

Good.....you got your answer. Merc calls it "clutch dog rattle" and says it hurts nothing but your nerves......and makes your pricey new OB sound like a piece of junk.

I have a 90 on a light boat with a high pitched SS and as you say, change props to heavier/more pitch and it gets worse.....but I like the performance of my "noisy" prop so I just minimize the time that I idle in gear.

Mark