I recall mechanics referring to floats as “heavy” from way back in the day, but it wasn’t until I started tinkering with vintage bikes that I discovered they actually meant the floats were no longer air tight, but had begun to leak, usually along the seam, slowly filling up with fuel, hence, heavy… And since they were taking on bilge, they no longer stopped the flow of gasoline when the carberator’s float bowl was at capacity. This old Suzuki has a “heavy float” Can you see the fine, minute crack in the tank of the float? Yeah, me either, until it began spewing excess fuel from the overflow tube and I dis-assembled it to locate and repair the fault…