[NSRCA-discussion] Bearing tip for OS 1.40 RX

[Rcmaster199 at aol.com]

Tom, 
Been using Castor Oil as an after run oil and in my fuel (mix of syn and 
castor) for a very long time. Works great and I have no issues with varnish or any 
adverse affects. Until recently, I stored my stuff in the garage in hot and 
humid Florida. In general bearings in my Webras last about 400 runs or so 
before they need replacement. 

The only "premature" failure so far has been the 160's bearing (lasted longer 
than "50-100" though), and which was primarily caused by lean idle and mid 
range settings. There were also other circumstances that didn't help the bearing 
(about 8 month idle time between Florida and New Jersey)

I agree it probably isn't as simple as  what was stated, but Ed's point is 
that OS has a winner with the EFI bearing, so why not use that part from the 
start at the factory? Makes sense to me.

MattK



In a message dated 7/2/2006 11:50:32 PM Eastern Standard Time, 
Tom.Koenig at actewagl.com.au writes:
Hi Guys,
Please dont take this the wrong way and I dont want to rain on your 
parade-but...

I dont think it's as simple as what you say. May I ask why you are pouring 
castor oil in there? ( OK I know why..but...)
I have seen/experienced symptoms like you describe-but generally in motors 
where the set-up parameters may not be optimal. Ie; pipe too short and prop too 
big and no crankcase cooling, wronfg fuel and compression ratio.

No crankcase cooling can cause the pump to get too hot and boil fuel. This 
shows up as all sorts of symptoms and genarally causes havoc. Also, if that 
engine is getting too hot whatever castor you have left in there will burn, 
perhaps causing a varnish build up and the rest is history.

However all bearings will wear and the big 2 strokes usually let you know 
when the idle suddenly turns to custard. Then you must immediately change 
bearings.

Check over all possibilities-the Japaneses usually know what they are doing ( 
and if they dont-they'll never admit anyway) but down here, all the OS's run 
perfectly once the set-ups are correct.Having said that -expect to change 
bearings every 50-100 flights depending on climatic conditions.

Ofcourse I place a caveat on this- I use a YS <VBG>

Good luck and best regards

Tom

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org 
[mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of R. LIPRIE
Sent: Monday, 3 July 2006 1:21 PM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] Bearing tip for OS 1.40 RX


You no Ed,

            You are as right as anyone could be. OS is a very good engine 
without  that dang piece of junk ball bearing. And I I've made complaints and I 
no I'm not the only one that has. But I don't no why they keep putting that 
thing in there. They do no what that bearing does. But like I told them you would 
 get better sells of your engines if you would put the good ball bearing in 
there. Because everyone is starting to find out that the OS ball bearing that 
is stock is junk. So everyone just keep complaining.

Matt
----- Original Message ----- 
From: Ed Alt 
To: NSRCA Mailing List 
Sent: Sunday, July 02, 2006 10:09 PM
Subject: [NSRCA-discussion] Bearing tip for OS 1.40 RX


This is an FYI for anyone with a new OS 1.40 RX.  Thinking about running with 
the stock bearing for even a short time?  Think again.  I was anxious to get 
a new model flying for this weekend and decided not to take the time to first 
swap out the junk stock bearing in a new RX.  I figured if I dosed it with 
after run oil after every flight I could get through he weekend and then do the 
mandatory swap to a sealed bearing.  Here's the full history.  

Friday, June 30 I did two break in runs on the ground.  Didn't do any after 
run between these two runs.  They were only 30 minutes apart. What could 
happen?.  Another 30 minutes after the 2nd break in run, did a short flight.  Had a 
transmitter trim lever problem, landed quickly, de-fueled, ran it dry, 
literally ran nearly 20 squirts of Amsoil Metal Protector through it.  Doused it.  
Got it home, added a full carb barrel of castor oil for good measure and worked 
it through.  Yeah, that ought to do it.  Dehumidifier running all day, all 
night in the basement...

Saturday, July 1 dawns.  Bearings still feel OK.  Head to the field.  Fly.  
Work a carb barrel of castor through it.  Repeat for 3 more flights.  Note that 
the bearing is starting to feel rough already.  Take it home, swap for a 
sealed bearing.  Note that the bearing is rusted already and that the crankshaft 
has light scoring from the inner race turning on it.  7 runs, handled like a 
newborn baby.

IMO, it is a disgrace that OS continues to produce this engine with a trash 
bearing that can't stand up to even the most careful use for more than a day.  
They KNOW what should be in there, since they do it for the EFI version.  
Lesson learned, if I ever do use another new RX, I'll never again make the mistake 
of doing even a single run without first swapping the main bearing.  It's not 
like the sealed bearing is all that expensive either.  I get them locally for 
a little over $11 each and they work great.  You don't even have to waste 
money on an overpriced Boca or EFI verson from Tower.

Ed
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