i have a briggs 287707. i don't know the type. its code puts it as a 95 model. it originally came with the walbro lmt that has an anti-afterfire solenoid. i bought the motor used and in great shape.i didnt have the electrical connections for the solenoid on the carb, so i cut the needle off. it ran great for several months. the bowl screw hole stripped out and so i just have the body of that carb sitting in my shed. a friend recently gave me an lmt 77 (to my best knowledge) with no bowl, float, inlet needle, etc. i transferred the parts off my old lmt on to this one and sometimes the inlet needle leaks a bit and it runs really rich causing it to backfire, flood, and shoot flames. i actually caught the side of my mower on fire because of this. i checked my valves and set them to specs. i set the idle mixture screw to 1 1/2 turns out. what else can i do to get it to run leaner. i'm thinking my friend possibly could have drilled the jet for racing, because thats what we are into, i just want it to run.