The Stovebolt Site Forums The Shop Area Engine Shop Exhaust Manifold Heat Riser Valve

My 38 stuck between, mostly in the "heat on" position but not completely closed. I had a perennial hard-to-start-hot issue because there was too much heat in the carb. When I shut it off hot, it would boil the gas out of the bowl and into the intake. It was like trying to start a hot engine with the choke on. After a lot of effort I was able to loosen the heat riser up enough to move it but could never get it free enough for the thermostat spring to work as it should. I ended up jamming it into the heat off position and using the choke to assist with cold running. When the weather is cool I let it sit & idle for a couple of minutes before driving. With the manifolds connected there is plenty of heat in the carb by then.