Caca in the fuel will be jerky too. Bits of paint and such. Buy some brand new spark plugs. Gap them then install them. Run your bike. No better? Oh well that was cheap, but as it didn’t work you need to do a couple other things.
Have you opened the tank cap while the bike is running? Better now? Yesâ€â€unkink the breather hose. No? -- Did you try pulling out the choke a tad? Did it run better? Yes? OK, Check your fuel side. Drain each of your carb bowls into a clean jar. Look at the fuel you drained out. Dirty gas come out?
The fuel side should start with the draining the bowls, then go to the tank and at least partially drain it too. Disconnect the fuel line and place a hose on the petcock port and the other end of a hose into a clean jar. Open the petcock and observe both the fuel flow rate and the fuel itself. Good flow rate? Clean Fuel? You can skip dropping the petcock, maybe! Now onto the carbs. If you got dirty gas when you drained the bowls, you need to inspect and clean the hidden fuel filter. Drop the bowls, the pilot jets the main jets. Inspect them. You might even need to blow them out. BE careful of the main jet tube's collar. Real careful dropping the air mixture screws tiny o-rings and washers and springs…If you find some garbage in any of the jets, blow the jets out put everything back and take a ride.
If you think your problem is electrical, find a friend and borrow his coils. Borrow his ignitor too. Swap these parts out to see if you can isolate the problem.
You issue sounds fuel related. I have had a fuel starvation problem and a dirty gas problem before. Most issues with our rides have to do with the fuel side.
These are just some steps. If your carbs are real dirty you’ll need to clean em proper.
Gotta go Ocean Key Resort is calling…
