prop wobble?

[macgyver69]

I am a first time boat owner - just bought a 76 Silverline 16T with a Mercruiser 140 I/O. When checking out the engine and drive with it running, I noticed the prop seemed to wobble a bit. Nothing I would call severe, but are they supposed to run true or is a little play normal? BTW, engine was running at 1500 RPM in Forward.<br /><br />Thanx in advance.

 

[LubeDude]

Re: prop wobble?

Originally posted by macgyver69:<br /> I noticed the prop seemed to wobble a bit. Nothing I would call severe, but are they supposed to run true or is a little play normal? <br /><br />Thanx in advance.

Yep, they are suppose to be true, perfectly true. You may have a bent shaft, or a bad bearing.

 

[Silvertip]

Re: prop wobble?

You need to determine if the prop is not running true or if the shaft is not running true. Tilt the motor down as far as you can go without hitting the ground. Using a block of wood and a pencil, position the pencil on the block of wood with the point right at the center of the drive shaft. Turn the prop by hand. If the shaft is not running true it will indeed wobble around the pencil point. If its ok, the prop has one or more blades that are not true and by running the engine it tricks the eye into thinking something is wobbling. Use the same process to check blades. They should run in the same plane.

 

[walleyehed]

Re: prop wobble?

Is this a Michigan wheel aluminum???

 

[macgyver69]

Re: prop wobble?

Thanx for the advice - as soon as it's not -30 out, I'll try the pencil test. <br /><br />Kenny - I have no idea what kind of prop it is - where would I look?

 

[gatorred]

Re: prop wobble?

take the prop off and see if the blade's have sight of impact on prop,see if shaft is moveable lose,sloppy it can move i little in and out .20 shim or free play you drop the oil out, if it's chunky yunk stuff it bearing,hope you ran it with water like ear's on motor if not you burned up impeller all this cost money prop is cheepest thing of all i have Mercruiser 120 book to plus websight, scanner to i put page on out drive if needed