Whats the idea behind 2 C clips on third?
The 3rd gear snap rings are notorious for breaking causing the bike to have two neutrals
Some guys machine a wider snap ring groove to accept a second snap ring.
What I have found is that most bikes with the 3rd gear snap ring problem have other issues that cause the snap ring to fail in the first place.
Worn gear dogs, worn out shift forks, poor shifting habits, and improper maintenance to name a few.
And I'm sure there are a few snap rings that failed because they were weak.
If you have a snap ring fail, get out your service manual and carefully measure and compare your readings for the shift fork fingers as well as the pin that rides in the shift fork drum slots. Measure the slots in the shift drum in several places, especially where there are bends in the slots.
Check out the dogs on the gears as well as the slots of the mating gears.
Likely you will find other issues that caused or greatly contributed to the snap ring failure.
One more thing... Any time we pull a K5 trans... we replace all the snap rings and, we only open them just enough to get the ring over the shaft.