I recently rebuilt my Losi 5T after an accident . I changed my gas to 89 and I’m using castor two stroke 927 as recommended by OBR . My needle setting are 1 1/4 on the low and 1 3/4 on the high . I adjusted the high to about 11/2 and it’s still running rich . I’m using 25 :1 with the castor 927 . I’m getting a black residue from my pipe and spark plug is a little wet with some residue and it’s smoking a lot . Should I lean it out more ? I don’t want to seize up the engine . Here’s a pic of my spark plug and you can see the residue from the engine .