BEST sparkplug for a mer xr2 150 1986

[17rogue70]

right now im running the ngk plugs and dont feel they are right for my app. at a fast idle it seems to be loading up with fuel. complete rebuild of the carbs, rebuilt fuel pump, disconnected the oil inj properly with the timimg adjustted to 25*. idle control removed. idles great , top end runs like a sewing machine high idle seems not right. lots of smoke and loading up . mix ratio is 50:1, compression is between 100psi and 115 psithrough out the cylinders engine sat for several years but was awaken properly.completely new fuel system from the tank to the engine. any thoughts or suggestions. im thinking the plugs maybe too cold for the mid range rpms. could a large pitch prop lug it down enough to cause this scenario. 14 1/4 x 23 prop.




thanks in advance
mike in fla

 

[Chris1956]

Re: BEST sparkplug for a mer xr2 150 1986

That prop could lug the motor, although, that would not show at high idle. You will need a very light boat to spin that prop, BTW. carb Float levels are set properly? Idle mixture (all six) adjustments set properly?