1968 Evinrude Big Twin, Big Twin Electric, Lark 40 HP Outboards Service Manual, Page 45Get this manual
Figure 5-4Thermostat
Figure 5-5 Removing Heat Switch
TURE SWITCH heat switch, installed in the head of the lower cylinder (electric start models only)is in series with warning light the control Should irregularity develop in the cooling system and cause abnormal water jacket temperatures, the switch closes the warning light circuitSee Figure 5-5The switch checked submerging it in hot Using test light to check the contacts and thermometer to check temperature, the contacts should found to close at temperature of 211 60 at 1750 70See Figure 5-6
and glossy in appearanceon some painted surface.swhich the Stik will not leave mark, it wi1l necessary to hold the Stik against the surfaceSee Figure 5-7