Mercruiser 3.0 shaking at front motor mount

[fairshopperguy27]

As sort of an extension to my previous post where I was having trouble with installing a new gimble bearing which was figured out.

We took the boat (2006 bayliner 175) out for a week long camping trip, the boat ran great except for at idle in neutral it would shake a bit and clatter at the front motor mount and if you trimmed up it would also shake and clatter. I got it to quiet down somewhat with tuning on the air idle screw, but it's still there. My question is: are the bottom 2 nuts on the front motor mount supposed to be tightened up by wrench? When aligning I could only barely get my hand down there to hand tighten them up. Do you think this is my problem?

 

[Alumarine]

The 2 front lower motor mount bolts that attach to the stringers should be tight.
Your idle might be too low as well if it shakes. It should be approximately 650 rpm in gear.
When you trim up it puts a load on the alternator which might cause the idle to drop even further.

 

[fairshopperguy27]

The 2 front lower motor mount bolts that attach to the stringers should be tight.
Your idle might be too low as well if it shakes. It should be approximately 650 rpm in gear.
When you trim up it puts a load on the alternator which might cause the idle to drop even further.

The lag bolts that go into the stringers are both tight, it's the two nuts on the bottom of the adjustment shaft that I can't get to by wrench to tighten, which led me to believe that hand tight would be fine.

 

[Alumarine]

Well, they should be good and tight. You don't want any play.
They have jam nuts to ensure they don't come loose.

 

[Bondo]

it's the two nuts on the bottom of the adjustment shaft that I can't get to by wrench to tighten, which led me to believe that hand tight would be fine.

Ayuh,.... The top nut is what the motor rides on, it sets the alignment,....

The bottom nut is the jam-nut for the top 1, they should be much tighter than finger tight,....

The beauty of workin' on boats is movin' the "Stuff" that's in yer way of doin' a proper repair,...

 

[fairshopperguy27]

Ayuh,.... The top nut is what the motor rides on, it sets the alignment,....

The bottom nut is the jam-nut for the top 1, they should be much tighter than finger tight,....

The beauty of workin' on boats is movin' the "Stuff" that's in yer way of doin' a proper repair,...

OK thanks, I'll find away to tighten it up. Bayliner left no room for a wrench down in there.

 

[rayodunne]

It was the same on my boat and I bought two cheap wrenches and cut them short to work.