You did not say, so let me presume that you have the same roughness on one or both mags. Further you did not say but I expect that your mechanic is satisfied with the drop in rpm when on one mag or with the carb heat on.
Accepting these things, we would all agree that the engine is running very lean for some reason. You can test the fuel feed by just opening the gascolator drain and watching the fuel flow. You can test the manifold for leaks by plumbing in a vacuum gauge long enough to watch the engine idle. An intake leak is unlikely in this case because it should show up mostly at idle and become progressively less of a problem as the engine accelerates. On an older engine that has broken in you could test the mixture by looking at the sparkplugs but on a newly rebuilt engine that has only ever idled the plugs should look pretty black. One question that comes to my mind is the adjustment of the float setting and I wonder if your newly rebuilt carb leaks fuel when it is sitting without the engine running. I would rather hear that it drips than that it is not leaking because I know what it takes to stop one from leaking. Three mechanics tried to stop mine from leaking without success, which caused us to accept the idea that leaking was a good thing and would keep grass from growing under the front tire. The problem with leaking is that you cannot know when the float is set correctly. I developed a procedure to test the float setting with the engine running to prove that the setting was not too low. Remove the carb bowl drain plug and replace it with a hose nipple which is commonly available at a plumbing supply house. Attach a 12' piece of clear tubing to the nipple and route it up alongside the carb body and then out away from the propwash. You will be able to see the working float level with the engine running and you should be able to measure it despite the hurricane conditions. This test should cost no more than $10 and take about 15 minutes. If the level is correct then you can eliminate one large set of problems and go on to another area. I do not know how quickly the low float level begins to affect engine operation. I do know, from personal experience with a sunk float, that the engine will operate quite well with the float level too high. Good luck, Bob Condon __________________________________________________________________________ ______ To unsubscribe from this list please send mailto:[EMAIL PROTECTED] ___________________________________________________________ T O P I C A The Email You Want. http://www.topica.com/t/16 Newsletters, Tips and Discussions on Your Favorite Topics
<<attachment: winmail.dat>>
