RCGF 21CC-Twin Operator's Manual page 12

7. Use one of the 5x35mm SHCS with 5mm lock washers and flat washers to align the
propeller washer on the propeller and use the Dead Center Hole Locator to mark the
position of the remaining holes.
8. Drill the remaining three holes in the propeller using the same technique as step 6.
9. Mount the propeller to the engine using the 5x35mm SHCS with 5mm lock washers
and flat washers. Be sure to use threadlocker.
Adjustment of the Engine
Each RCGF Engine has been factory preset. However, differences in elevation will
influence the performance of the carburetor. To obtain optimum output of the engine,
slight adjustment of the carburetor may be necessary
Engine Functions and Adjustments