Help me my gs does not run

[Hango]

I bought a 78 gs 1000 that has been sitting for a while???? I rebuilt the leaking fuel petcock. ,the battery is strong, it starts with full choke. Runs on 2/3/4 cylinders. Not crisp. Does not idle.
Where do I begin?
i will replace the spark plug.ugs then?
ideas
thanks

[tom203]

Best to keep it in one forum section... I replied in electrical, but it is probably more fuel related.

[JTGS850GL]

I bought a 78 gs 1000 that has been sitting for a while???? I rebuilt the leaking fuel petcock. ,the battery is strong, it starts with full choke. Runs on 2/3/4 cylinders. Not crisp. Does not idle.
Where do I begin?
i will replace the spark plug.ugs then?
ideas
thanks

Probably time some serious maintenance including, a complete carb rebuild, valve adjustment and proper carb sync afterwards.

[Buffalo Bill]

Probably time some serious maintenance including, a complete carb rebuild, valve adjustment and proper carb sync afterwards.

Yes, you're going to have to update all the maintenance neglected for years. As all of us had to do.

[RJordan09]

Probably time some serious maintenance including, a complete carb rebuild, valve adjustment and proper carb sync afterwards.

This. Start with valves, then a FULL carb clean with complete disassembly and acid dip. See where you're at when all that's done. You should replace the o-rings for the carb boots when you have the carbs off as well, that will start to address any air leaks.