Checking prop shaft for true/ strait

[aook23]

I would put the prop nut back on the shaft and use a wrench to slowly turn the shaft while watching the dial indicator. I would also disconnect the battery so you don't hand start the boat.

Thats a good idea, im gonna try that tonight

[Waynes345]

A fake-a-lake is good to have on hand regardless. There is also a thread on the board about a home made version. Here is a link to the one I bought:

http://skidim.com/prodinfo.asp?number=FAK01

[aook23]

So heres the deal, I used a Dial Indicator and attached it to the trailer and ran the boat for only 5 seconds and got a reading of .008 and .010 of of movement but considering the trailer was shakin a bit from the boat engine rumble ( which was sweet by the way ) I am being optimistic and I think that is minimal for the setting and should find out for sure if there is a vibration tomorrow as soon as I water test the boat once I install the new prop ... fingers crossed..

Anyone have any input on what they think based off those readings ..

[drewsky]

Ok, Technical question, Is that Dial indicator in MM or inches?

[DOCDRS]

I found this post very interesting and did some searching. You need to check the propshaft by hand not with the motor running. plus where on the shaft did you check it pre or post strut. I couldn't find a tolerance other than .002 but thats on outboards. Don't have mine here but is there any movement (lat/vert) just by applying some force to the shaft by hand....ie cutlass bearing play? when you put the prop back on and spin it by hand , if it binds more at a particular point then the shaft may be bent...or the alignment could be out ?
If it binds or your gauge shows it out I would unbolt the engine/propshaft coupler and recheck your shaft trueness and engine alignment to determine the cause.

[aook23]

Ok, Technical question, Is that Dial indicator in MM or inches?

It was in inches

[aook23]

DOC,

I cant seem to get the thing to free up at all in "Neautral" Does every one else seem to be able to free spin there prop at the "Neuatral" Postion because it feels like fighting engine compression or something,,,

I checked it pre strut but like I said it was running, which your are sayin is not a accurate reading wich I completly believe.

I get my prop tonight so I guess that will have to be the real test ...

also what should I tourqe the new prop to ?