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Prop Balancing
Posted: Fri Feb 17, 2012 10:21 pm
by Legeorgen
My 0320 metal Sensenich Rebel has a noticeable vibration when it's under a take off and climb loads at full throttle or in cruise above 2400 RPM. Not real bad, but noticeable and more so than the 912ULS I have been used to flying the past several years. I think maybe I need to have the prop balanced. Maybe this is normal for an 0320? I'm not sure. I don't know anyone flying and 0320 to compare it to.
Has anyone balance a metal Sensenich and did it make a lot of difference in smoothing out the engine?
Bruce G 357R
Prop Balancing
Posted: Fri Feb 17, 2012 10:21 pm
by Robert Johnson
Bruce, I bought a new Sensenich for my Rebel & O320 H2AD (160HP) and found it to be real smooth. Obviously a new prop is factory balanced. Was your new or used. Also I assume you checked both tracking and diameter runout to verify crankshaft flange is running true ???-Bob Rebel "652"
Prop Balancing
Posted: Fri Feb 17, 2012 10:21 pm
by Wayne G. O'Shea
Another possible cause (and especially on the A & B series with rearward carbs) is an intake tube vibrating against the motor mount, with the extra torque at take off . The mount is VERY close to the intake tubes on the conical engine mount and even placement of the hose clamps on the intake rubbers is critical. I think Bruce's is a Dynafocal mounting (which shakes even more in relation to the mount) so it could be something attached to the engine making contact within the cowling, etc and not necessarily the prop that is causing the problem. Get out the flashlight and look for rubbing and any signs of clearance problems (especially the carb intake filter box hitting the sides of the opening). While your at it do like Bob suggests and check your prop tracking again.
BTW Bruce, how do you keep your 912S carbs from throwing off?? Seems to be a big problem around here!
Cheers,
Wayne
----- Original Message -----
From: Robert Johnson (
ob.johnson@sympatico.ca)
To: murphy-rebel@dcsol.com (
murphy-rebel@dcsol.com)
Sent: Wednesday, August 28, 2002 10:01 PM
Subject: Re: Prop Balancing
Bruce, I bought a new Sensenich for my Rebel & O320 H2AD (160HP) and found it to be real smooth. Obviously a new prop is factory balanced. Was your new or used. Also I assume you checked both tracking and diameter runout to verify crankshaft flange is running true ???-Bob Rebel "652"
Prop Balancing
Posted: Fri Feb 17, 2012 10:21 pm
by Legeorgen
Bob,
This was a new prop from the factory. I did check the tracking but not the diameter run out. I will try that first. Thanks
Bruce G 357R
Prop Balancing
Posted: Fri Feb 17, 2012 10:21 pm
by Legeorgen
Wayne,
Thanks for the help, I'll check all these items you mentioned.
Bruce G 367R