I've still got my users manual - it says the gap should be 0.030" (0.76 mm).
how to replace plug wire on a toro mower
Champion RJ18Y
.030
Tecumseh Part #611049 - Champion Spark Plug #RCJ8Y
plug gap for toro ccr 3650 is .025
Champion RJ19LM will work.
Get a spark plug socket and wrench that fits the plug body and remove it by turning counter-clockwise.
The correct plug gap for my Toro GTS 6.5 horse mower is 0.035
.025
Autolite 458
The spark-plug gap for a toro 6.5 hp self paced walk behind lawnmower is a 0.035 spark plug. You can easily find nice spark-plugs for sale on sites such as eBay.