I have an MDS .58 with a very sensitive high speed needle. It is very difficult to adjust and it ends up running very hot about 300 degrees F !!!!).

If you richen or lean the high end just a little bit then it quits. It is also very sensitive to attitude changes. For example, when you raise the model's nose, the engine goes noticeably leaner and when you lower model to point straight down it is way richer.
On my other models this happens when the engine is going lean. However, this thing will not let me richen the mix, it starts burbling and quits!

I have changed the plug, disassembled and cleaned the carb, changed the fuel tank plumbing, ..........


Any ideas??

Thanks