PTO Clearance

[kesso2118]

I have just changed all the bearings in my .21 MAC and CMB Outboards and I was wondering whether there is a specific clearance that should be used between the disc on the PTO Shaft and the PTO Housing. I am interested to know to ensure there is sufficient clearance between the crank pin and the PTO Disc.

At the moment I have it set at .020" between the PTO Disc and the PTO Housing and I can feel some "end play" in the crank.

Thanks,

James

 

[Ron Drake]

I have just changed all the bearings in my .21 MAC and CMB Outboards and I was wondering whether there is a specific clearance that should be used between the disc on the PTO Shaft and the PTO Housing. I am interested to know to ensure there is sufficient clearance between the crank pin and the PTO Disc.

At the moment I have it set at .020" between the PTO Disc and the PTO Housing and I can feel some "end play" in the crank.

Thanks,

James

In the PTO it is better to have a little clearance. As the drive dog gets sloppy, it will "push" the shaft up, and if it is too long, it will bind the PTO disc against the crank pin, causing all sorts of headaches. Loose wont hurt it. That is the bad thing about the PTO piece floating, we have talked about milling a groove on the PTO shaft below the bottom PTO bearing, and attaching a small e clip to stop the walking, but haven't tested the idea yet.

Premo, on Drake's compootur

 

[kesso2118]

Premo,

Thanks for the advice.

I just closed up the gap between the disc and the housing to .015".

Regards,

James