Left bank high egt (80 degrees higher)
By cleaning the vacuum piston sliding surfaces and leaving a clean surface The pistons slide very easily and there is no sticking of either slide, the EGT's no longer wander.
Now the left EGT starts out even with the right and remains close till around 3800 rpm then the left begins reading higher up through 4600 rpm by about 80 degrees and over 4800 rpm it begins dropping and getting closer to the right. At full throttle the egt's are maybe 10-20 degrees apart.
Today I replaced the left EGT probe and it made little difference from the old one. The left egt gets just over 1400 degrees in this midrange rpm while the right is about 1320 degrees.
The carb bowls are clean and the floats not disintegrating. The carbs have never been messed with and I am assuming the needles are both the same as this large temperature difference didn't used to exist and has seemed to get worse over the last year or so. The rubber gaskets for the vacuum chamber are both pliable, look new and have no cracks or splits. The engine has 800 hours. The carbs are syncronized every year and hold their sync very well from year to year. Fuel pressure is 4 lbs,there are no leaks or seepages on the carbs.
Anyone got an idea what would cause this midrange lean condition/high EGT on the left side.