Model Tech Fun Fighters P-51 ARF Assembly Instructions Manual page 27

WARNING To prevent dust and debris from entering your engine during the fitting and aligning of the cowling, we strongly
suggest covering your engine's exhaust port, carburetor opening and needle valve inlet with small pieces of paper towel.
PRO TIP To make it easier to line up and install the cowling and to minimize the size of the cutout, we removed our engine's
cylinder head. This shortens the height of the engine, making it easier to slide the cowling into place.
❑ Temporarily slide the cowling over your engine and onto the fuselage, then secure the spinner backplate onto your engine's crankshaft.
❑ When satisfied with the alignment, use pieces of masking tape to hold the cowling securely to the fuselage.
step 2: instaLLing the coWLing
❑ Measure and mark the locations on the cowling that you must cut out to
clear your engine's cylinder head and carburetor.
❑ Carefully cut out the cowling to clear your engine. Work slowly, removing
small amounts of material at time, and checking the fit often.
❑ Line up the front of the cowling, using the spinner backplate as your guide.
When aligned properly, the cowl ring should be centered with the spinner
backplate and there should be about a 1/16" - 3/32" (1.6mm - 2mm) wide gap
between the front of the cowling and the back of the spinner backplate.
❑ Draw three marks on the fuselage at the back edge of the cowling to help
locate the positions of the three cowl mounting screws. Draw one mark at
the top of the cowling and on each side of the cowling.
IMPORTANT The upper cowl mounting hole should be position along the
centerline of the cowling and the two side mounting holes should be positioned
approximately 1-3/4" (44mm) up from the bottom of the cowling.
❑ Remove the cowling and measure the distance from the three marks that
you just drew to the center of the firewall.
☞
Write these measurements down. They will be transferred to the cowling
to ensure that the cowl mounting screws are positioned correctly.
❑ Slide the cowling back into position and realign it, then use pieces of
masking tape to hold it securely in place.
❑ Measure forward from the back edge of the cowling the distance that you
measured in the last procedure. Do this at each of the three cowl mounting
screw locations, then drill 1/16" (1.6mm) diameter pilot holes through the
cowling and into the edge of the firewall.
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