Chainsaw Repair

About the only feed back I can get is TPI data. Nothing about things like Oxygen & Heat in the exhaust as there is no active sensor device there like on motorcycle or car systems. So can't tell if its fuel starvation thing, an ignition thing or what. Probably because I don't understand the system enough. This is an area I need to explore. And... is there a direct relationship between modules and carbs?? Can you mix them? Almost seems as if the carb tuning is fixed. Don't see anyway of tweaking. Obviously there must be or porting could be risky if the results needs more fuel than a preset system delivers. Lots to learn here for me obviously.

Have a 550 on the bench now with hot start issues. Runs one tank of fuel...then won't restart.