Home › Forum › Ask A Member › Evinrude 18hp temp › Re: Evinrude 18hp temp
September 22, 2016 at 1:25 am
#44485
You would normally shoot the thermostat pocket for consistent temp readings. That is assuming the motor has a thermostat. You will get the temp the thermostat opens at most closely that way. Shooting other places can lead you to errors as to powerhead temps. I believe the old OMC #378065 stat was 135 degrees, but the new stat it SS to is 143. Not that big of difference. Sierra still makes the brass stat (with slot in the top hat #18-3553, but shows it to be 143). The seal #310058 that fits around the head of the stat fits with the skirt down. Sierra & Mercury also make this same seal. Check ME for part numbers. Hope that helps.
Dan in TN