Be mentally prepared to rebuild carbs. But before getting to that, try a few more things.
Check fuel filter. Obstructions will limit fuel input to the carbs.
Remove fuel selector valve and clean. Blow it out with compressed air in Fuel and Res positions. This is also a good time to check the fuel hoses for any degredation that may be leading you up to a carb rebuild.
Check and if necessary change spark plugs.
Pull out spark plug wire from plug boot. Trim off about 1/8" inch or bit more if you have slack......cram back into the boot and clamp with new ziptie. The wires can get corroded and will not transfer spark from the wire into the boot easily.
Open ignition module box.....where the other end of the spark plug wires run. Check for water or corrosion on the terminals. Clean terminals/connectors with a brass bristle brush. Reapply electrical contact grease to protect.
1989, eh? Perform compression check. Maybe worn rings, scored rotary valve and other more involved projects.
