Demon NO Go

Yep,if it increases speed when you cover center carb theres a lean condition,you'll want to search out that problem,watch the vacume gauge as you cover the center carb,vacume should increase,the trick with the propane works well(doesnt mess up the paint)and will be a big help looking for a vacume leak,checking the float levels will be a big help knowing they are right then looking for the lean problem after that will be easier to pinpoint.