What is the "AMPS" reading on your Z-4000 throttle that is hooked to the bridge rectifier?
Multiply that number by 2. In round numbers this is the WATTS of power that the bridge rectifier is generating as heat in doing its task of converting AC to DC.
So if the AMPS reading is 0.5, then 2 x 0.5 = ~1 Watt. The bridge rectifier will feel warm.
If AMPS is, say, 2.0, then 2 x 2.0 = ~4 Watts. The bridge rectifier will feel very warm and likely too hot to handle.
If AMPS is, say, 5.0, then 2 x 5.0 = ~10 Watts. The bridge rectifier will likely burn your finger.
What you can/should do is fasten the bridge rectifier to a piece of scrap metal to act as a heat-sink to pull the heat away from the bridge rectifier. If using a bridge that looks like your initial photo, that's why there's a mounting hole in the center! You're "supposed" to use heatsink compound to make for better heat transfer to the metal plate. But heatsink compound is annoyingly over-priced and my experience just about any kind of household Lithium grease or the like is good enough.
