TOPIC:

3rd test. Bike has sat for 6 full days. Turned on fuel, listened to bowls fill, touched the starter and it fired up immediately, again. Reduced the choke for a 1200 RPM warm-up idle.
This appears to be the solution to the notorious hard start problem and the modification is remaining as installed.
Amendment: I screwed-up when I cut the brass and silicone for the picture. Sorry 'bout that. Reverse the lengths !!!!! The exact lengths are not critical but the brass tube must be longer then the silicone tubing.!!!! Neither can extend into the choke-piston well (for obvious reasons) !
Reverse the lengths !!!

I will implement this in blind faith based on your experience on the first main carb set. Now, that will be a real hard start test after sitting for who knows, maybe 6000 days?

Another immediate start after sitting since the last weekend ! Then an outrageously enjoyable 126K "scoot around the patch" ! This bike is simply too much fun !
If you've got a "Hard-Start" issue.....pull up your panties and try the Choke-Air mod. It'll take a couple of hours and YES the carbs have to come off and YES the lids have to be swung out of the way to remove the diaphragms............ but it works ! Or you can continue to try blowing up the engine with starter fluid and wearing out the starter and it's mechanism. It'll cost you about $3.00 for the silicone and brass.

Great to see the tests are proving the theory in practice! Congratulations scotch!
We talked about it, but this still makes me wonder... My engine was overhauled, and should be pretty tight. What effect would have on it installing this modification? It's for start up only anyway, so it might make it easier despite.
Scratching my head.....

It would be very interesting to see if an unmodified set of carbs will start a new engine easily. That was the premise when I suggested this. So now you're the "guinea pig" !
If you do have starting issues.....you know what to do !

Stan from the points Scotch made about the design of the carb specifically, I think this mod is applicable to any age and condition of carb or engine, as the issue addressed is not caused by wear, but fundamental design?

The only thing that might 'disguise' it's effect is if you happen to have a super-fast starter motor which will re-prime the choke circuits faster than a slightly tired one (just mean a faster engine spin = more vac = more fuel draw), but again the theory means even then you should see a measurable improvement with the mod?