Questions and Answers If you have general RC questions or answers discuss it here.

Problem when adjusting Thunder Tiger engine. particulary, when adjusting Air Bleed Screw.

Reply
Old 01-21-2010, 02:39 AM
  #1
MasterSpace
Thread Starter
 
Join Date: Jan 2010
Location: Sana\'a, YEMEN
Posts: 4
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Problem when adjusting Thunder Tiger engine. particulary, when adjusting Air Bleed Screw.

I bought an engine (Thunder Tiger .42). But faced a problem when adjusting the Air bleed screw.

Breifly, when I try to
adjust the engine to idle and raise the plane nose 15 degrees, the engines stops directly ...

The manual instructions supplied with the engine is that I should determine the idle speed and then raise the aircraft nose 15 degrees. if the engine stops, I should rotate the screw half turn clockwise and repeat again the same process till I get the required and smooth running

By the way, The best result was reached (but the engine still stops) when the screw is fully closed.

I hope anyone has idea about this issue to advice me.
MasterSpace is offline  
Reply With Quote
Old 01-21-2010, 07:55 AM
  #2
Steve Steinbring
 
Join Date: Jul 2007
Location: Homestead, FL
Posts: 584
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Problem when adjusting Thunder Tiger engine. particulary, when adjusting Air Bleed Screw.

When adjusting an air bleed setup closing the adjustment screw makes the mixture richer by allowing less air into the mixture. Conversely to lean the setup open the screw to allow more air into the mixture. The bleed air setups are a bit more difficult to adjust IMO than using a needle valve setup but work well once adjusted properly they perform fine. Make small adjustments about an 1/8th of a turn at a time. A properly adjusted the engine should come up to full power when the throttle is opened quickly without lugging down from being too rich or quitting from being too lean.
Steve Steinbring is offline  
Reply With Quote
Old 01-21-2010, 04:32 PM
  #3
MasterSpace
Thread Starter
 
Join Date: Jan 2010
Location: Sana\'a, YEMEN
Posts: 4
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Problem when adjusting Thunder Tiger engine. particulary, when adjusting Air Bleed Screw.

Thanks Steve for your reply...
Actually, I tried to perform my adjustment precisely. conversely, I adjusted the needle valve at full power and was okay.

I know that closing the screw makes the mixture richer but I got the best result when fully closing the bleed air screw. also the transition between the idle speed and full speed is smooth.

I thought the problem comes with something related to the tank or the distance between the tank and the engine but when trying another engine OS, It was running properly.
MasterSpace is offline  
Reply With Quote
Old 01-21-2010, 05:51 PM
  #4
Lnewqban
 
Lnewqban's Avatar
 
Join Date: Apr 2007
Location: South Florida
Posts: 4,037
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Problem when adjusting Thunder Tiger engine. particulary, when adjusting Air Bleed Screw.

Welcome to the RCU forums, MasterSpace.

Is your engine old enough as to have excessive clearance between the throttle barrel and the carburetor body?

It seems to me that it may the cause for your low end adjusting screw being out of range.
It idle rpm's, the vacuum in the engine is maximum, and that will try to pull air into the crankcase from anywhere it can.
Once that air is in, the amount supplied by the low-end screw may result excessive for a proper combustion.

Regards!
Lnewqban is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

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



All times are GMT -8. The time now is 07:45 PM.