fuel line boil on 728 Broadmor

[JRHIMER 0]

Here is an interesting finding which I wonder if anyone else has encountered. After mowing for awhile the engine on the tractor seemed to be fuel starved. After checking the carb float setting, fuel filter, etc. couldn't seem to find the problem. I installed a clear vinyl fuel hose between the filter and the carb inlet. When the fuel supply problem again happened I noted that the fuel was flowing in the wrong direction as indicated by the bubbles in the line. It appeared the carb was too close to the very hot muffler, so I fashioned an exhaust shield to insulate the carb from the muffler, and no more fuel boil. Anyone ever run across this? Just curious....