I’ve opened up my two thermo valves to troubleshoot why one is warming up and one not. What I discovered is that the little brass plunger under the spring that closes the valve hole is missing in both. I assume that someone removed them in the past, so the hole is now permanently open in each choke. However I’ve noted above that some people block the hole in the carb when deleting the thermo-valve, which in my understanding would have the undesirable effect of making the mixture richer, unless this is compensated for elsewhere?
PS: I started looking at the thermo valves because of cold start issues where the choke doesn’t open quickly enough after starting. Specifically, the vacuum-operated choke diaphragm has no effect whatsoever on the clock spring of the choke, no matter how far it’s adjusted, and hence the choke butterflies are staying fully shut for too long after starting. The diaphragms look ok, so I assume I’m looking for a vacuum leak next.
PS: I started looking at the thermo valves because of cold start issues where the choke doesn’t open quickly enough after starting. Specifically, the vacuum-operated choke diaphragm has no effect whatsoever on the clock spring of the choke, no matter how far it’s adjusted, and hence the choke butterflies are staying fully shut for too long after starting. The diaphragms look ok, so I assume I’m looking for a vacuum leak next.