#1 carb slide flutters??

[gripit_N_ripit]

hola fellows. I found a 92 fj for sale on craigslist about 1 1/2 hour drive from my home. Bike has 19k miles on the clock and runs fine according to owner. i rode my fj up there yesterday evening to have a look. when i got there he had the air filter box off of the bike so i could see the carb slides operating. While he would rev the engine you could see the far left carb slide flutter, it also sounded like it was missing in sync with the flutter. Is that normal?? I recommended he compression test the engine and clean the carbs but he took no interest and just wants to sell it. My question... When you twist the throttle are the slides mechanically pulled up or do they open up by the air flow needed?? what would make the slide flutter??

[hein]

The throttle controls the butterflies mechanically and the slides are controlled by engine vacuum. If the slide on #1 carb does not open or "flutters"  check for a vacuum leak upstream , make sure that the vacuum port plug is in place on that carb,also check the carb diaphragm for damage. Popping the tank off and checking for this is a pretty quick job. If you plan on buying this bike bring along a leakdown tester or at least a compression gauge. Good luck, Hein.