If you have any of the intake manifolds mentioned in my earlier post and are having detonation and or piston failures, I would run some test to determine if the manifold may be the cause.
Running the upper vent hoses into a catch-can is another method of testing for vibration induced float bowl foaming.
The vent line that comes out of the bottom of the float bowl on most carburetors should not be routed into the catch-can. This vent hose is usually connected to a stand pipe that dumps fuel on the ground almost every time the brakes are applied. The fuel level in the front of the float bowl rises under hard braking. The purpose of the stand pipe is to keep the fuel level below the pilot jet transition holes to prevent enriching the mixture or flooding the engine during braking.
The top of the catch can must be below the bottom of the float bowl. The catch-can must be well vented. The ends of all lines that dump into the catch-can must NEVER be allowed to be submerged in the fuel that may fill the catch can. If the vent lines in the carburetor are pinched, partially restricted with fuel or partially filled with fuel, the float bowl chamber may not experience atmospheric pressure. A carburetor that does not experience true atmospheric pressure at all times, can make the Air Fuel Mixture very unpredictable.
The billet manifolds in the pictures look like the style of manifolds I have had problems with. I have also used manifolds that look like the ones in the picture and not had any problems. I have used old hardened OEM type manifolds and Boysen type rad valves and not had problems. Every bike has different vibration characteristics due to crankshafts that not true, loose main bearings or lose main bearing pockets, worn main bearing journals on the ends of the crank webs, improperly rebuilt counter balancers, pistons that are not the same weight as the OEM Honda piston, broken or missing cylinder head stays, loose motor mount bolts, cracked frames, after market frames (have a different resonance frequency than OEM frames), shock absorbers, tires, tire pressure....... the list goes on.