Too many times members have had the trouble and expense of water flooding into the cabin because the passenger side cowl drain was plugged with debris.
It occurred to me that this should be pretty simple to fix without removing the cowl while providing a port through which the drain could be inspected and any debris vacuumed out.
PDF available at bottom of the post.
Here is the port with its removable plug. The plug came from Amazon, a 1" Flush Mount Black Plastic Body and Sheet Metal Hole Plug. 10 pieces for $8.46 Canadian. One day delivery.


I cut a 1" hole in the cowl with a drill and a 1" diameter hole saw. Ideally the hole should be from 1" to 1/ 1/64" diameter. My hole saw cut a little to large so I had to enlarge the snap ring on the plug. By chance the head of a hammer was a little larger than the inside diameter of the snap ring. I heated the plastic just enough to force the hammer head into the ring. I let it harden up and it fit perfectly, so do a test on the hole size the hole saw cuts.
Under the 1/16" thick plastic I found the end of the rubber from which the 'fingers' are made. The hole should have its centre 1" from the side edge and 7/8" from the rear edge of the hood seal channel. I made mine 1" from the rear edge which gave me a slight problem with the cut rubber edge being too close to the hole. To get better access to the top and bottom faces of the cowl I removed the four T-25 screws and cut the plastic cable tie near the third screw.
Now I cut the rubber off with scissors flush to the forward edge of the forward finger, I cut right the way across the rubber flap. What you want is for the rubber to be just clear of the back of the installed plug.


With the rubber cut it needs to be cleaned of the contact cement on it and the back of the cowl, I used contact cement cleaner. I applied contact cement to both faces and let them become tacky before I pressed them together. I used a small clamp to hold the face together and pressed them together around the edges with my fingers.


Now we can see some debris covering the drain hole.


Using a couple of plastic tubes taped together we can vacuum the debris out.


Put it all back together, install the plug and we have a neat solution to the often expensive problem.


The tools I used on this little project.
A drill with a 1" diameter hole saw.
A pair of scissors to cut the rubber.
A screwdriver with a T-25 bit in it.
A pair of snips to cut the cable tie.
A 'C' clamp to hold the rubber and cowl together while the contact cement set.
A deburring tool.
The plastic cap, show upside down.
And a lashed up vacuum hose.