Go Back  RCU Forums > Glow Engines, Gas Engines, Fuel & Mfg Support Forums > RC Fuels
Reload this Page >

Changing from 10% nitro fuel to 5% in an OS46

Notices
RC Fuels Nitromethane, Castor Oil, Synthetic, heli fuel, 4 stroke, etc...Fuel Q&A is here!

Changing from 10% nitro fuel to 5% in an OS46

Old 10-22-2014, 01:47 PM
  #1  
Roo Man
Thread Starter
My Feedback: (1)
 
Join Date: Mar 2008
Location: Lakeland FL
Posts: 568
Received 0 Likes on 0 Posts
Default Changing from 10% nitro fuel to 5% in an OS46

I have 3 gallons of 5% fuel and want to use it. I currently run 10% in an OS46 on a Sig Senior Cadet, what kind of carb adjustment will I need to make for this change, leaner, richer, no chg?

Gary
Old 10-22-2014, 02:48 PM
  #2  
1QwkSport2.5r
 
1QwkSport2.5r's Avatar
 
Join Date: Oct 2006
Location: Cottage Grove, MN
Posts: 10,419
Received 77 Likes on 70 Posts
Default

Originally Posted by Roo Man
I have 3 gallons of 5% fuel and want to use it. I currently run 10% in an OS46 on a Sig Senior Cadet, what kind of carb adjustment will I need to make for this change, leaner, richer, no chg?

Gary
Going from 10% nitro down to 5% nitro will require a slightly leaner needle setting.
Old 10-22-2014, 06:40 PM
  #3  
Roo Man
Thread Starter
My Feedback: (1)
 
Join Date: Mar 2008
Location: Lakeland FL
Posts: 568
Received 0 Likes on 0 Posts
Default

Originally Posted by 1QwkSport2.5r
Going from 10% nitro down to 5% nitro will require a slightly leaner needle setting.
Thanks for the input, will try tomorrow.

Gary
Old 11-09-2014, 08:07 AM
  #4  
JPMacG
My Feedback: (2)
 
Join Date: Jan 2002
Location: Ivyland, PA
Posts: 2,299
Received 1 Like on 1 Post
Default

Did you try it? What did you think? My experience with 2-strokes is that going from 10% to 5% makes no perceptible difference. I tune my engines every time I fly, so I would not have noticed a difference in the needle. But my engines seem to have just as much power and idle the same on 5 as 10.
Old 11-09-2014, 12:17 PM
  #5  
Roo Man
Thread Starter
My Feedback: (1)
 
Join Date: Mar 2008
Location: Lakeland FL
Posts: 568
Received 0 Likes on 0 Posts
Default

Haven't had time due to illness and weather but will definitely try it next time at the field.

Gary
Old 01-08-2015, 01:23 PM
  #6  
stuntflyr
 
stuntflyr's Avatar
 
Join Date: Oct 2007
Location: Tucson, Arizona
Posts: 1,891
Received 2 Likes on 2 Posts
Default

I used 24 gallons of leftover C/L Stunt fuel from 5 to 15% nitro and all about 20-22% total oil and can say the OS 46 AX is a great running engine with a great ability to burn about any fuel you put in it. Afer all of that flying it sounds as if it could use bearings!
Chris...
PS I had a 46 SF that was the same way, it died in a horrible straight in due to learning about battery charging and its necessity.
Attached Thumbnails Click image for larger version

Name:	Kaos 3.JPG
Views:	84
Size:	219.5 KB
ID:	2062318  
Old 03-31-2015, 02:53 PM
  #7  
iFrinkso
 
Join Date: Mar 2015
Location: Mooresville, NC
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Default

On the other hand, does raising nitro affect piston cylinder fit on these AX engines if you already performed breakin at lower nitro - or a lower average cyl temp?

Last edited by iFrinkso; 03-31-2015 at 03:22 PM.
Old 04-02-2015, 04:16 AM
  #8  
Hobbsy
My Feedback: (102)
 
Hobbsy's Avatar
 
Join Date: Dec 2001
Location: Colonial Beach, VA
Posts: 20,370
Likes: 0
Received 25 Likes on 25 Posts
Default

The piston to liner fit is self regulating, nitro changes won't effect anything any more than flying on a cool morning and then on a hot afternoon.

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 - Manage Preferences - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.