87 ignites easier than 89, I rarely have an issue with my carbs and almost never use carb cleaner. I only use it when disassembling them for a problem.This goes for my antiques too. I think if an engine is set up correctly (so few seem able to do so) it will run trouble free for a very long time with only basic maitenence , oil change etc.. You can spray cab clean around any intake rubbers and listen for the idle to change, if it does you have a vacuum leak. There is no reason to use anything higher than 89 octane unless you have put higher compression pistons in (or raised your compression in any other way) Those ratings are not quality ratings. The terms regular, plus, and premium are misleading. That rating is the fuels resistance to pre-ignition so the lower number actually burns easier. You should run the lowest octane you can without pinging.Pinging is the fuel igniting before it is supposed to. You may need to clean your carb if there is dirt in the fuel you used.
