Reply To: Carb issues Evinrude 15 HP

[Don]

OK, well the can’t judge engine temp by telltale temp because the telltale is at the beginning of the cooling flow. Telltale temp should never got hot, it will usually be cool or warm.
It is interesting that there are a few different style high speed nozzles, one for a 6hp, the other for the 8hp. Your 15hp takes the 396605, which is unavailable, which nozzle did you use?
It sounds like you have the sync set up OK, but are you sure the throttle butterfly is closing fully at idle?
It is not uncommon to have to restart a warm engine with the choke, especially in the hot weather, mostly due to fuel volatility and heat soak issues. So, don’t leave the adjustment needle excessively rich just so it will start without the choke.
Engine temp is measured on top of the cylinder head, we would like to see about 140 degrees at low speeds, it will cool down a bit when run at higher speeds. The thermostat sits on a rubber seat with a spring holding it in place, so high water pressure can push it off its seat at higher speeds cooling the engine down a bit. So, it is not uncommon to find debris between the thermostat and seat keeping the engine from warming up at low speeds.
Sounds like you left the original idle hose in place which isn’t a good idea…Todays fuels rot these hoses pretty quickly creating debris which can plug up the carb.
Try to post a video of the engine running poorly, there are many possible causes other than just carb issues…