	*Here's the probable reasons for a poor top end in an aero engine.*
The cause of an engine running poorly at top end varies. One problem may be the compression ratio too high or low for the fuel you are using. Your engine could be detonating from premature ignition or on the other side of the spectrum running retarded from too low a compression. Read these links about compression: Compression Ratio -- Why it matters -- What it causes How do I set the squish band? (The head clearance.)
	Another problem may be a modified exhaust system. Too much back pressure will cause an engine to overheat and the running changes.
	Too little back pressure can cause the pressure to the tanks to be erratic. This will cause variation's in running as the pressure changes in the tank.

	See also cause of erratic running

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©2004-2009 Model Engine Corporation of America, All rights reserved. MECOA and K&B are Registered Trademarks of Model Engine Corp. of America Registered U.S. Patent Office

©2004-2009 Model Engine Corporation of America, All rights reserved.
MECOA and K&B are Registered Trademarks of Model Engine Corp. of America
Registered U.S. Patent Office