Notices
Glow Engines Discuss RC glow engines

O.s. 2.10

Old 08-19-2003, 10:52 PM
  #1  
fatfreddy17
Thread Starter
My Feedback: (43)
 
Join Date: Jul 2003
Location: Plymouth, WI
Posts: 84
Received 4 Likes on 2 Posts
Default O.s. 2.10

I was wondering what kind of set up other guys are using on your O.S. 2.10. I am running a Zinger 20 x 8 prop, and 15% Wildcat fuel. No fuel pump.

The reason I am posting this is because the engine leans out as my flight progresses. Moving the fuel tank is not an option, ( it is level with the carb).
Old 08-20-2003, 11:26 AM
  #2  
Matt Kirsch
My Feedback: (21)
 
Matt Kirsch's Avatar
 
Join Date: Jul 2002
Location: Spencerport, NY
Posts: 7,350
Likes: 0
Received 0 Likes on 0 Posts
Default O.s. 2.10

You might need a fuel pump.

What size fuel lines are you running? With no pump, the pickup tube should be the next size larger than normal.

BTW, what's an OS 2.10? 2-stroke? 4-stroke? Twin? I didn't know OS made an engine that size.
Old 08-20-2003, 02:21 PM
  #3  
h82crash
Senior Member
 
h82crash's Avatar
 
Join Date: Mar 2002
Location: ramona, CA
Posts: 841
Likes: 0
Received 0 Likes on 0 Posts
Default O.s. 2.10

Its the BGX 3500.
Old 08-20-2003, 02:40 PM
  #4  
JWN
Community Moderators
My Feedback: (42)
 
JWN's Avatar
 
Join Date: Mar 2002
Location: Georgetown, TX
Posts: 6,897
Likes: 0
Received 1 Like on 1 Post
Default O.s. 2.10

My BGX runs great without a pump. The tank is about 3" behind the firewall and I run only large fuel tubing. Medium will not pass enough fuel. I opened up the holes in my tank to accept large brass tubing as well. It turns an APC 20X8 2-blade at 9K RPM on the ground. Fuel is Magnum #1 2-stroke. It must be set richer on the ground than you would expect as the engine unloads quite a bit in the air and will lean out if you do not allow for the extra revs. The only time I've had a problem with this engine was when I first tried to run a tuned pipe on it. The compression is high enough that it detonates and overheats unless you install 2-3 head shims. It should also be noted that the factory muffler is junk. It is VERY restrictive and will cut down on power considerably while creating a lot of back pressure which could cause the engine to run too hot in some conditions. I'm currently running a Slim Line large volume Pitts muffler and the engine is very happy.

John
Old 08-20-2003, 03:49 PM
  #5  
Gone to a Higher Plane
Banned
 
Join Date: Oct 2002
Location: Austin, TX
Posts: 264
Likes: 0
Received 0 Likes on 0 Posts
Default O.s. 2.10

Large fuel lines don't make much sence when almost all the large motors come with .40 - .60 size nipples. You can have 1/4 i.d. fuel line but it is only going to let the amount of the nipples i.d. so the only way to solve that is to drill out the nipples.
Old 08-20-2003, 05:25 PM
  #6  
JWN
Community Moderators
My Feedback: (42)
 
JWN's Avatar
 
Join Date: Mar 2002
Location: Georgetown, TX
Posts: 6,897
Likes: 0
Received 1 Like on 1 Post
Default O.s. 2.10

Small diameter tubing will restrict the fuel flow over a distance. Using large tubing does in fact make a difference. And, in the case of the BGX, while it has only a slightly larger than normal nipple on the carb, the hole is in fact larger than you would find on a .60 sized engine.

John
Old 08-20-2003, 11:18 PM
  #7  
CurtD
My Feedback: (1)
 
CurtD's Avatar
 
Join Date: Dec 2001
Location: Dallas, GA,
Posts: 335
Likes: 0
Received 0 Likes on 0 Posts
Default O.s. 2.10

The big 2-strokes (OS, Moki, others) need larger diameter fuel tubing. It's not just the size of the nipple on the carb. The smaller diameter fuel tubing creates more restriction than the carb fuel draw can overcome. Don't just replace the fuel tubing either. You need larger brass tubing in the fuel tank stopper, larger tubing in the tank, and a large diameter clunk.

I'm running a 24 oz. tank on my Moki 2.10 set up with everything in the fuel system large diameter. I can set the needle where I want and it will hold that setting from full tank to empty (or as close as I care to get). It shows no signs of needing a pump or regulator, either.
Old 08-20-2003, 11:32 PM
  #8  
fatfreddy17
Thread Starter
My Feedback: (43)
 
Join Date: Jul 2003
Location: Plymouth, WI
Posts: 84
Received 4 Likes on 2 Posts
Default O.s. 2.10

I am using medium size fuel tubing, with a 24 ounce tank.

Also, I am using whatever tubing came with the tank on the inside of the fuel tank.

This O.S. sure runs quite compared to the Moki's at my field. I am thinking that the Slim Line Pitt's style muffler may be too restrictive?
Old 08-21-2003, 03:26 AM
  #9  
Warren
My Feedback: (72)
 
Warren's Avatar
 
Join Date: Oct 2002
Location: Alpine, CA
Posts: 473
Likes: 0
Received 0 Likes on 0 Posts
Default O.s. 2.10

Medium is working just fine on my Moki 2.10: 2-2.5 ounces a minute is not a huge flow rate.

If you can richen it way up, don't bother changing your tubing out.
Old 08-21-2003, 02:13 PM
  #10  
JWN
Community Moderators
My Feedback: (42)
 
JWN's Avatar
 
Join Date: Mar 2002
Location: Georgetown, TX
Posts: 6,897
Likes: 0
Received 1 Like on 1 Post
Default O.s. 2.10

Originally posted by fatfreddy17
This O.S. sure runs quite compared to the Moki's at my field. I am thinking that the Slim Line Pitt's style muffler may be too restrictive?
I seriously doubt it's too restrictive as it has twice the outlet area of the stock muffler. Mine is pretty quiet all things considered, but I attribute that to a decently designed muffler and prop.

John
Old 01-04-2004, 08:52 AM
  #11  
Willy RDRC
Senior Member
My Feedback: (1)
 
Join Date: Oct 2002
Location: Raleigh, NC
Posts: 125
Likes: 0
Received 0 Likes on 0 Posts
Default RE: O.s. 2.10

JWM, am considering a BGX 3500 for a Dave Patrick Extra. See where you like a tuned exhaust pipe versus OS's stock muffler. Can you tell me what tuned pipe works well and where I could obtain it? Thanks. RDRC Willy.
Old 01-04-2004, 12:14 PM
  #12  
JWN
Community Moderators
My Feedback: (42)
 
JWN's Avatar
 
Join Date: Mar 2002
Location: Georgetown, TX
Posts: 6,897
Likes: 0
Received 1 Like on 1 Post
Default RE: O.s. 2.10

The pipe I run is the Macs Quiet Pipe #1096 for 35cc engines. It's available through Macs directly at http://www.macspro.com . Tower does not list this pipe online any longer, but they may be able to special order one for you for less than full retail. Of course, just about any hobby shop should be able to do the same.

John

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 or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.