Plugs don't get black from getting fuel but no spark. That woudl be impossible.
You're either running way too rich, or you have weak spark and imcomplete combustion, if your plugs are black.
First step is obviously to replace the plugs. Check the spark on each cylinder with the brand-new plugs beefore you put them in. If the spark is good, then run the bike. See what happens. I would check the air filter while I was in there.
If it's not spark, and the air filter is fine, and the ECU isn't throwing any trouble codes, check the fuel pressure with a gauge. That would mean the regulator is suspect.
Your symptom also sounds like it could be a tank vent issue, so you might want to run the bike with the cap not quite closed and see if it affects the problem, but I doubt that is your issue.
You're either running way too rich, or you have weak spark and imcomplete combustion, if your plugs are black.
First step is obviously to replace the plugs. Check the spark on each cylinder with the brand-new plugs beefore you put them in. If the spark is good, then run the bike. See what happens. I would check the air filter while I was in there.
If it's not spark, and the air filter is fine, and the ECU isn't throwing any trouble codes, check the fuel pressure with a gauge. That would mean the regulator is suspect.
Your symptom also sounds like it could be a tank vent issue, so you might want to run the bike with the cap not quite closed and see if it affects the problem, but I doubt that is your issue.