yes, also remember that when you go to a smaller jet, one number size difference can make a huge difference in the air/fuel ratio. you may have a 70 jet now, but if you drop to say, a 65...that's dropping way too many sizes all at once. when you lean out a carb by changing the jet size, you need to go in tiny increments.
like a/c man said...if you have a 70 jet, only drop down 2 sizes to a 68 and try it.
i think i need to re-jet one of my carbs too, but i am running 16:1 gas/oil mix for the break in period so i won't really know if i have to lean it out until i can drop to 20:1 or 32:1 gas/oil mix.