The Stovebolt Site Forums The Shop Area Engine Shop 1941 GMC 228

I rebuilt my 228 several years ago, but have driven it very little since. It just never seemed to run as good as before. I started it for the first time in a couple of years last night and it just seemed to be running too rich and wouldn't smooth out. I am confident that the carb is in good shape. I just shut it down...disappointed as usual. I notice that the area just below the carb is smoking when I shut it down and the paint is burnt to a crisp on the manifold in that area. Shortly after I did the rebuild, the muffler/exhaust system got loud. I am wondering if maybe my muffler collapsed and back-pressure is causing the rich running condition, or is the heat riser valve not rotating. Any ideas would be appreciated. I really want the ole truck to run good again so I can de-stress when I drive it and not re-stress. Thanks, Jim.

Jim,
I have one of those too. I suggest you drop the exhaust pipe at the manifold and make sure you don't lose the little doughnut that is usually in that flange. Then start it up and see how it runs. That will answer your possibility of an exhaust system constriction. If this doesn't get it running its time to pull both the intake and exhaust manifold and see what may be in one of those intake or exhaust passages. It sure sounds like there is blockage up near the engine block in an exhaust port with the heat description you give.
Normbc9