Notices
O.S. Engines Support Ask Bill Baxter your questions about O.S. Engines.

Inverted OS 70 Surpass II run problems

Old 09-04-2006, 08:07 PM
  #1  
ghost-RCU
Thread Starter
My Feedback: (10)
 
Join Date: Jan 2002
Location: STEPHENS CITY, VA
Posts: 292
Likes: 0
Received 0 Likes on 0 Posts
Default Inverted OS 70 Surpass II run problems

I have a new OS70 Surpass II in a Sig Sundancer. I've tried many different needle settings but the thing will not run with the engine inverted. When glow heat is removed it dies reguardless of throttle position, Any solutions without repositioning the fuel tank. There isn't any space to to lower the fuel tank. Right now my only other option is to buy a new cowl & mount it on its side. Help! Thanks.
Old 09-06-2006, 01:20 PM
  #2  
Bax
My Feedback: (11)
 
Join Date: Apr 2002
Location: Monticello, IL
Posts: 19,483
Likes: 0
Received 6 Likes on 5 Posts
Default RE: Inverted OS 70 Surpass II run problems

First off, how does the engine run when you have it upright? You need to get the engine 'dialed in' with it upright, first. Then see how it runs inverted. Your symptoms sound like the engine's much too rich. Either remove the engine from the model and get it set up on a test stand, or mount the fuselage inverted in a cradle and get the engine set up there.

Once you have it well set up in the upright position, you should not need much adjustment when you invert it.

If the fuel tank's too high, you may never be able to solve your difficulty. The center of the tank should be a bit lower than the center of the carburetor, but no more than about 3/8" lower.
Old 09-06-2006, 08:36 PM
  #3  
ghost-RCU
Thread Starter
My Feedback: (10)
 
Join Date: Jan 2002
Location: STEPHENS CITY, VA
Posts: 292
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Inverted OS 70 Surpass II run problems

I have run the engine in upright. I called Hobby Services & was told to put a Perry pump on it & was told that this will solve the problem. Is this true or did I just waste my time & money. My pump should be here from Tower on friday. When I ordered the Sundancer from Tower I called Hobby Services & was told then that the OS 70 was the best engine combo for this plane. I've had many planes & motors over the past 17 years & have never had this kind of problem. I can't lower the fuel tank any lower because it about as low as I can get it now. I almost ordered a YS.63 for this plane now I wish I had.
Old 09-07-2006, 10:09 AM
  #4  
Bax
My Feedback: (11)
 
Join Date: Apr 2002
Location: Monticello, IL
Posts: 19,483
Likes: 0
Received 6 Likes on 5 Posts
Default RE: Inverted OS 70 Surpass II run problems

We'd not know who would recommend a pump. You'd need a pump if the tank's far away from the engine, or the tank was very, very low.

Inverted running can make engines be problematic to run. You may also try a new glow plug. Many times, if the engine quits when you remove the battery lead, it's a plug problem. Use an O.S. Type F plug.

If the engine runs properly upright or side-mounted, then there's nothing wrong with the engine. You may need to run an on-board ignition system to get good inverted running at lower throttle levels. The engine should be fine at full throttle.
Old 09-08-2006, 06:59 PM
  #5  
ghost-RCU
Thread Starter
My Feedback: (10)
 
Join Date: Jan 2002
Location: STEPHENS CITY, VA
Posts: 292
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Inverted OS 70 Surpass II run problems

This really Pi**es me off. Your guys gave me bad advice. Now even if i return it I will have to pay shipping & I ask If I should buy an onboard glow system instead & was told no it wouldn't help. You need to find out who told me to buy a pump. If your guys don't know what they are doing then you need to get someone that does.[>:]
Old 12-12-2006, 09:26 PM
  #6  
Texan2
My Feedback: (4)
 
Texan2's Avatar
 
Join Date: Nov 2002
Location: Beaumont, TX
Posts: 234
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Inverted OS 70 Surpass II run problems

I had a similar problem with a YS110 because of the wrong type of plug. I'm now using F-plus and onbord glow at idle. Problem solved.
Are you using an F plug?
Old 12-12-2006, 09:32 PM
  #7  
ghost-RCU
Thread Starter
My Feedback: (10)
 
Join Date: Jan 2002
Location: STEPHENS CITY, VA
Posts: 292
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Inverted OS 70 Surpass II run problems

Yep using an F. Thanks
Old 05-20-2007, 05:03 AM
  #8  
hacke
Junior Member
 
Join Date: Jun 2006
Location: harnosand, SWEDEN
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Inverted OS 70 Surpass II run problems

Hi. Please forgive me for not speak so good english.
However. I just have the same problem with my O.S 91 surpass, the engine will die as soon I take the glow-heater away. I have try many different of settings but in the end it looks like it get too rich(mounted the right way it works perfect). Then i changed the fuellines to a line with a little smaller inner dia. and suddenly it works. Now it´s running perfect and m a happy O.S pilot. The engine is mounted in a Midwest Citabria 80"
Old 05-20-2007, 11:42 AM
  #9  
rctrax
Senior Member
 
Join Date: May 2002
Location: Mosinee, WI
Posts: 597
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Inverted OS 70 Surpass II run problems

I have an os 70 mounted inverted with the fuel tank center line about 3/4" to 1"below the centerline of the carb. This seems to be the right combination as I also have two os90's with the tank mounted on a level with the carb centerline and they don't run well at all at idle without glo heat, but do run good at WOT.
Old 05-21-2007, 10:30 AM
  #10  
Bax
My Feedback: (11)
 
Join Date: Apr 2002
Location: Monticello, IL
Posts: 19,483
Likes: 0
Received 6 Likes on 5 Posts
Default RE: Inverted OS 70 Surpass II run problems

As I stated above, inverted running can be problematic with any model engine. You may need to add an on-board glow plug battery pack to enable the engine to idle well and have a good acceleration from idle to full throttle.
Old 05-21-2007, 02:45 PM
  #11  
ghost-RCU
Thread Starter
My Feedback: (10)
 
Join Date: Jan 2002
Location: STEPHENS CITY, VA
Posts: 292
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Inverted OS 70 Surpass II run problems

I changed my fuel & it runs great inverted. I've run both 15% & 30% cool power Heli fuel with good results. It seems to idle a little better on the 30% & it makes nice smoke. This motor is strong, strong, strong. Thanks Bax for the help.

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 -

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