Can I Cover The Part Of The Caruburetor Where Air Enters With Foam?

it would not be too good of an idea to just cover the intake with foam. Motorcycles are designed so that the air filter box is big enough for the bike to breathe in the appropriate amount of air to feed the engine. If you have any cracks or rips in your intake system that let extra air in it can actually destroy your motor. If you don't sllow it to get enought air it can severely lower the performance of your machine. How badly was the boot damaged? I have heard wonderful things about flex-seal and fixing air boots with it, that and maybe layering some kind of tape and then flex seal over the top. Also there are very cheap replacement air filter set ups on ebay ayou can find any kind of rubber tube that seals the carb to the air box it will work too, get creative with it!