Reply To: 1975 Johnson 15R75C 15 hp

[Sam M.]

I beleive that the way the telltale works on this early version of this style of 9.9/15hp motor is that it will only discharge water out the telltale when the thermostat is open.  So once the motor warms up, then the cooling water will apear.  That’s just how it works – no need to modify.  Simply watch some Chrysleroutboarddude videos on Youtube of ths Johnson 9.9hp and Johnson 15hp versions of this motor with the green lower leg as Ben explains it there.  That’s where I learned this from!😁

Also, keep a close eye on the spark plugs for cross-threading when screwing them back in.  Due to the orientation of their holes, I find it harder to tell if they’re going in properly than with sparkplugs sticking straight out of a cylinder head.