ENGINE GURUS - First Spring Engine Start - Sum Ting Wong

[speed220mph]

Terry, If it's a Holley you're dealing with, know that they don't like to sit. A backfire will cause problems, too, such as blowing out the power-valve diaphragm. Check it the engine backfired when staring it. As for the float bowls, they eventually drain over time, causing the gaskets at the float bowls and/or metering blocks dry out, which will cause internal leaks. If the floats and needle seem to be working--pull the sight plugs to see if the fuel level is correct--procede to step two. SNUG the float-bowl bolts. If they feel very lose, chances are you've found the problem. Beware: Over-tightening these bolts will bend the main body of the carb. This can be fixed, but it's a pain. Run the engine to see if the problem is corrected.

If snugging the float-bowl bolts doesn't work, remove the bowls. metering blocks and scrape clean the gasket surfaces. Here's come the pain part. Check that the carburetor surface the metering block seals against is perfectly flat using a small straightedge. A 6-inch machinist scale will work. Just lay it again this surface in several directions, looking to see that there's no light between the rule and surface. If it appears to be bent or warped, file flat this surface. Be careful here. This operation must be done with the carb off the engine and on a bench. Some wet-or-dry sandpaper on a flat surface works, too. Run the carb body back and forth on the paper and look for high spots . . . they'll be bright. File or sand until the full face of the gasket surface is clean. Now reinstall the whole mess with new gaskets, install it on your engine and see how she runs.