[NSRCA-discussion] OS 120 AX

[randy9004 at comcast.net]

I have been running the original stock bearing since I bought the engine over a year ago.  No problems with them yet.  I run 15% two stroke all sync fuel on a stock muffler with a APC 16X8.  I adjusted the throttle curve to adjust the feel on the throttle to what I like.  I was running an iron bay fuel regulator on my Venus 2; which worked great once I tapped the backplate.  It is in my Seagull Yak 54 90 now.

It appears that the QA on the bearings may be a little on the poor side.  Some appear to last the normal time and some just fall apart.

Randy  


 -------------- Original message ----------------------
From: "J N Hiller" <jnhiller at earthlink.net>
> The stock bearings in both my 120-AX’es failed prematurely, maybe two cases
> of fuel. The first one had serious corrosion, even on the shaft under the
> rear bearing as if it wasn’t properly lubed during assembly. The other one
> just got loose, (excessive prop rock) so I quit running it. I got
> replacement bearings from the local bearing store and left the seals on and
> it still feels fine after maybe 6 gallons.
> I have never experienced this kind of premature failure before and I have
> been running OS motors for about 30 years. Are they trying to build too
> large of a displacement in too small of case?
> Jim Hiller
> 
> -----Original Message-----
> From: nsrca-discussion-bounces at lists.nsrca.org
> [mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of John Pavlick
> Sent: Monday, September 03, 2007 8:40 PM
> To: NSRCA Mailing List
> Subject: Re: [NSRCA-discussion] OS 120 AX
> 
> Bob,
>  How much time is on it? We've had a few around here that ate the rear
> bearing in 50 - 100 flights. One of them ended up ruining the sleeve too
> (bearing debris). The solution is to replace the rear bearing with an OS
> 140Rx F.I. (sealed) bearing before it gets bad enough to cause other damage.
> The front bearing is a double sealed type already so you won't need to
> change that one. This is a really good running motor when you get the
> bearing thing straightened out.
> 
> John Pavlick
> http://www.idseng.com
> ----- Original Message -----
> From: Bob Richards <mailto:bob at toprudder.com>
> To: NSRCA Mailing List <mailto:nsrca-discussion at lists.nsrca.org>
> Sent: Monday, September 03, 2007 8:35 AM
> Subject: [NSRCA-discussion] OS 120 AX
> 
> I acquired a plane with an OS 120AX installed, and seem to be having some
> issues with it. It came with an APC 16x8 prop and stock muffler. Is not
> running as well as I think it should, but I did figure out I had some bad
> fuel. I plan to go out again today and tinker with it some more.
> 
> What fuel, prop, and what rpm figures should I be seeing?
> 
> Thanks in advance.
> 
> Bob R.
> 
>   _____
> 
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion


-------------- next part --------------
An embedded message was scrubbed...
From: "J N Hiller" <jnhiller at earthlink.net>
Subject: Re: [NSRCA-discussion] OS 120 AX
Date: Wed, 5 Sep 2007 04:41:05 +0000
Size: 19532
Url: http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20070905/dd20ba4c/attachment.mht