Fitting The Cowling Around The Exhaust And Final Cowl Touch Ups - Pipistrel Sinus Build Manual

Fitting the cowl around the exhaust and final cowl touch ups
The following task requires a little creative judgment.
Cutting the hole for the exhaust pipe:
Mount the lower cowl and estimate where the exhaust will protrude, it being that the
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outlet is angled and the end position won't be where the hole position will end up.
Try to have about 1cm around the exhaust for freeplay.
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When happy grind a hole with the Dremel and sand smooth.
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Apply some black silicone around the opening to seal the hole off from contaminants.
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Cutting the holes for the fuel refill nozzle and the fuel/water drain valve:
With the lower cowl already mounted, take a marker, reach into the engine and draw two
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lines on cowl's inner lining, directly underneath the fuel/water drain valve. The first
should be a straight line parallel to the fuselage's main axis. The other should be a
straight line at a 90 degree angle to the first.
Then gentle push the bottom cowl up against the refill nozzle, just hard enough to leave a
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mark on the cowl's inner lining, but not hard enough to damage it.
Remove the cowl and examine the marks you made. Find the spot under the fuel/water
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drain valve where your two lines meet and drill a hole with a 45mm diameter.
Now align the cowl so that you are looking at the spinner end from the firewall end. Find
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the indent you made with the refill nozzle. The hole for the refill nozzle must be 10mm to
the right and 10mm upwards from this indent (see photos below). Drill a hole with a
57mm diameter.
Use sand paper rolled up to do the final clean up of the holes. Clean up the odd bit of
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firewall fluff by cutting with a sharp knife, run a small bead of black silicone around the
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