I forgot to mention that you can also reduce the amount of smoke (and roughness) from cold starts by snipping the violet wire on the GP relay. This allows the GPs to stay energized for a longer period than originally designed, thus maintaining heat in the prechambers while the engine warms up. I placed a thermally switched relay into the violet wire circuit so that the GPs wouldn't glow for that longer period after the engine temp reached 50 C.