I'm somewhat new to wrenching my bikes and I'm loving it! :D
I have a 74 Yamaha TX 500 that keeps carbon fouling her plugs :(. I've put on slightly hotter plugs (D7EA from D8EA), narrowed the jets from #132 to #120, and put on K&N filters right on the throttle body.
She STILL fouls (black soot) the plugs almost to unusability within 15 minutes of hard riding.
What could it be? I've heard it could be an ignition issue or that I need an entire new carb.
What are your thoughts?