If the Carb is spitting Air-Fuel out of it, then the Reeds need to be inspected. A 91, the reeds will be relatively easy to Access, as they are external to the Crankcase. Carbs have be removed first, then the Intake Covers, and then the Reed Assembly. Upon reassembly, a Link and Sync will need to be done to insure the Carbs are opening equally, and in Synchronization with the Spark Advance
4 cylinder?
Have you got the correct Factory Service Manual? If not, get it
