Strange Noise

[lhall8]

I have just gotten my 1986 4.3 omc running, and I am concerned about a noise it is making. THis is my first boat and I do not know if there is something wrong, but it idles smoothely. Then if I accelerate (with it out of gear) it vibrates a little and makes a roaring noise. THis all happens when it is out of water. Is this normal or is there a problem.

 

[fendersfender]

Re: Strange Noise

I would remove drive and check gimbal bearing...it should move freely with no hesitation or rough spots

 

[cosander]

Re: Strange Noise

my gimbal bearing caused a nasty vibration

 

[ss9940]

Re: Strange Noise

Did you lower your outdrive while running on hose?

 

[lhall8]

Re: Strange Noise

Yes, I lowered it. Would the gimbal bearing still make noise when not in gear. Also, if I have to replace this, how hard is going to be, and is it expensive?

 

[jlinder]

Re: Strange Noise

On the OMC the shift is at the bottom of the drive where the vertical shaft meshes with the prop shaft. <br /><br />As a result, everything but the prop is turning all the time, no mater what gear is engaged. That is why you need to lower the drive anytime the engine is turning.

 

[lhall8]

Re: Strange Noise

Is there a kit that I can buy to replace the gimbal and all the seals

 

[Richard Petersen]

Re: Strange Noise

You really want to be absolutly sure what is worn out and vibrating before buying and tearing apart the drive. Pay a marina mechanic $30 or $40 to say what has gone bad. Make sure you can return new unused parts.

 

[cosander]

Re: Strange Noise

yes if the engine is spinning so is your gimbal bearing. grease it up and see if it changes.