RE: tower 46 troubles
You might try replacing the O-rings on the needles. They get worn and can cause air leaks eventually.
Also- the little clicker on the main needle can get worn and allow the needle to vibrate and turn in(leaner) or out(too rich) due to high RPM vibrations.
Are you running a filter on the pressure line between the muffler and the tank?
There is a lot of gunk in the muffler and stuff can flake off and eventually make it's way into the tank via the pressure line. Then it gets sucked up into the clunk and makes it's way to the needle. A tiny piece of carbon from the muffler can work it's way up to the carb eventually and make for intermittant running. It'll have you chasing your tail for hours. Then when you find it or figure out what it is-- it seams so simple. A tiny piece of gunk can reak havoc on the needles and carb.
I run filters in the pressure line and also in the supply line before the fuel hits the needle.
Also run a filter on your fuel jug. Filter the fuel BEFORE it goes into the tank on the plane.
Always fill the tank in the plane WITHOUT the filter on the clunk line. You don't want to risk pumping debris from your jug into your clunk filter. When you connect the line back up to the carb-- you've just introduced gunk from the fuel jug right into your carb. The line going to the carb should have a small 1" line and then a filter. That filter should NEVER be disconnected from the fuel line on the carb side. When fueling- you should disconnect the fuel line between the filter and the tank. Fill the tank and then reconnect to the filter.