72 25hp motor cover vibration

renaldoaoa

Seaman Apprentice
Joined
Aug 5, 2006
Messages
44
The cover I have rattles something fearce when under power. I have (i think) a gasket running around the perimeter thats cracked pertty bad. I'm guessing that has something to do with helping the noise vibration?

At any rate, what can I get to help stop the vibration of the cover? Anything purchaseable or a quick rig would help tremendously.

Thanks for the help!!
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: 72 25hp motor cover vibration

1 (or more) of the cowl lock down clamps isnt broken in any way is it? Will putting pressure on the top of the cowl lessen the vibration?
 

Lakester

Chief Petty Officer
Joined
Nov 17, 2007
Messages
428
Re: 72 25hp motor cover vibration

hello,

i am working on a similar issue on my 1971 85HP evinrude. it does not vibrate under power but my aft lower cover rubber supports are not in as good as condition as the front system is. standing water over time ie, rust has eaten some of the fasteners. well, i assume since all 4 drain holes in lower section of engine cover were plugged. :eek:

i do a heave-ho on lower unit. i watch the rubber systems to see if they move much. they are designed to move some, ie float.

do u have same? if it was mine, i would ck carefully if u have a lower system. i am thinking u prob do. is any of it loose?

u may want to run it [carefully] with cover off. ck it for vibration... it may help u to eliminate the variables.

i did go over the bolts holding the inside latch mechanism braket. sev bolts a bit loose. i also put grease on contact points where latch slides thru bracket.

if u have lower engine cover latches be sure the nuts, or fasterns there are secure. also be sure something inside is not hitting it. can u ID where any rubbing contact is happening?

regards
lakester :cool:
 

renaldoaoa

Seaman Apprentice
Joined
Aug 5, 2006
Messages
44
Re: 72 25hp motor cover vibration

HighTrim

Clamp isn't broke. The motor has a metal piece in the back that slides in, the top comes down and locks in the front.
This motor is a combo (elec/pull) and the rubber piece around the pull start looks to be in good order.

Just sitting here typing this, I was thinking maybe I can bend the back piece up a bit to maybe hold the top tigher.

Lakester
Everything is tight and works correctly, so I don't believe thats the issue. When Im going, I can put my hand on the top of the motor cover and the sound goes away.


*EDIT* Just took a look and it does appear that theres a gasket between the top and the motor. Its all cracked up and I assume it's just worn out, but I have no clue on where or what you would call this?



Thanks for the replys guys!!
 

Lakester

Chief Petty Officer
Joined
Nov 17, 2007
Messages
428
Re: 72 25hp motor cover vibration

hello,

sounds as if something unique to the cover is loose. u may be able to ID suspect items and shim with folded paper for a temp look-see...

well, that's how i would do it if it was elusive... and my problem. :)

i assume u r not pressing hard?, just using hand to absorb or stabilze it.

if it does not do it with top off... i'd just hunt n hunt some more on that top cover.

let us know

regards

lakester :cool:
 

samo_ott

Vice Admiral
Joined
Jun 18, 2006
Messages
5,125
Re: 72 25hp motor cover vibration

It's usually the gasket that wraps around the base where the cowling meets it. These can be bought aftermarket in some boating places.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: 72 25hp motor cover vibration

The cover seal for the 1972 25HP Johnson is part 316225. Your dealer should be able to provide it.
 
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