spraying carb cleaner on the carb you must be very careful not to get the rubber destroying cleaner in the choke pull off''s.. these control the cold start choke opening and prevent secondaries from opening when cold. also when these leak you now have vacuum leaks. with a vacuum guage you can check if the internal diaphram is ruptured.
with vac applied these devices should quickly move inward.
the other rubber would be the hoses connected to the carb. these also get damaged.
carb cleaner is only for metal , rubber is destroyed by this product.