Notices
Glow Engines Discuss RC glow engines

OS 65AX Liner Issues

Old 05-15-2020, 06:42 PM
  #1  
thailazer
Thread Starter
 
thailazer's Avatar
 
Join Date: Mar 2008
Location: Liberty Lake, WA
Posts: 1,547
Received 1 Like on 1 Post
Default OS 65AX Liner Issues

I picked up a used 65AX recently and it looked pretty good so I put it on a plane and flew it today for four flights with good runs each time. I noticed a strange grey sludge in the exhaust residue and decided to tear the engine down when I got home. The engine looked very good inside except for two odd things: The liner has some of its electroplated coating chipped off on the outside near the crank as you can see on the photo. There also was an significant amount of blackish carbon on the long muffler screw. The engine has very good compression and the TDC squish is very tight, just like a new engine. I could not find any of the coating bits in the crankcase and am wondering if OS would use a defective liner like that as the defect is on the outside, not inside. The inside of the liner and the piston look great with no scratches or scuffs.


Old 05-15-2020, 08:23 PM
  #2  
the Wasp
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,371
Likes: 0
Received 10 Likes on 10 Posts
Default

did you check the muffler to see if there is something in it ??

Jim
Old 05-16-2020, 03:48 AM
  #3  
A. J. Clark
 
A. J. Clark's Avatar
 
Join Date: Mar 2004
Location: Craigville, IN
Posts: 466
Likes: 0
Received 1 Like on 1 Post
Default

That looks a little like rust. Maybe from the bearing if it's been setting for a while. Was the residue there like that every flight ?
Old 05-16-2020, 03:58 AM
  #4  
thailazer
Thread Starter
 
thailazer's Avatar
 
Join Date: Mar 2008
Location: Liberty Lake, WA
Posts: 1,547
Received 1 Like on 1 Post
Default

Wasp.... You might be on to something. If there was a mud dauber nest in there that would explain the debris. I didn't see anything when I took it apart except the blackish carbon on the long screw.

AJ...... The grey sludge was still coming out after the fourth flight. I thought it might be just old fuel, as normally I have a slight film of red from the fuel I use. At any rate, the stuff coming out after the forth flight was still grey and not red. I wiped the plane down after each flight watching this stuff.

Old 05-16-2020, 05:54 PM
  #5  
the Wasp
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,371
Likes: 0
Received 10 Likes on 10 Posts
Default

can you take the muffler apart (like the older FX mufflers) ?

as for what AJ said, how smooth does the crank turn ?

Jim
Old 05-16-2020, 07:06 PM
  #6  
thailazer
Thread Starter
 
thailazer's Avatar
 
Join Date: Mar 2008
Location: Liberty Lake, WA
Posts: 1,547
Received 1 Like on 1 Post
Default

Originally Posted by the Wasp View Post
can you take the muffler apart (like the older FX mufflers) ?

as for what AJ said, how smooth does the crank turn ?

Jim
The crank turns fine and is smooth. The bearings look good. No bits of anything in the crankcase and the backplate is not scuffed. I did have the muffler completely apart and nothing inside but sludge and that blackish carbon on the screw inside.
Old 05-17-2020, 09:21 AM
  #7  
the Wasp
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,371
Likes: 0
Received 10 Likes on 10 Posts
Default

Originally Posted by thailazer View Post
The crank turns fine and is smooth. The bearings look good. No bits of anything in the crankcase and the backplate is not scuffed. I did have the muffler completely apart and nothing inside but sludge and that blackish carbon on the screw inside.
well if there is a lot of sludge that could be the problem, clean it out well before the next flight,
some times with a new engine you can get sludge while braking-in.

what kind/ brand of fuel are you using ?

EDIT: and how did you tune it ? running too rich is almost as bad as running it too lean for a ring-less engine.

Jim

Last edited by the Wasp; 05-17-2020 at 09:28 AM.
Old 05-17-2020, 10:39 AM
  #8  
thailazer
Thread Starter
 
thailazer's Avatar
 
Join Date: Mar 2008
Location: Liberty Lake, WA
Posts: 1,547
Received 1 Like on 1 Post
Default

Yeah, I am thinking it was past fuel residue left over inside the muffler. I cleaned out quite a bit and my bet is the prior owner used a castor based fuel. I am using Omega fuel and it has only a slight reddish tint so am hoping all looks normal after a good clean out.

I am just going to run the engine and see what happens as it ran fine. I did run it slightly on the rich side but not overly so.

The liner having part of it chipped away concerns me, and I guess OS has had issues in that area. Just glad it is on the outside and not on the inside!

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.