John - Here's a previous on-topic heat riser thread that might help figure things out.

In that thread is this video of the heat riser operating through the cycle.

I also found a related video that shows the operation, but also how the fellow modified the anchor pin end of the spring to fix what he considered a problem with the valve not operating correctly.

Hope this may help. wink

~ Dan
1951 Chevy 3 window 3100
Follow this story in the DITY Gallery
"My Grandpa Carl's Truck and How it Became Mine"
1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver)
US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)