carburetion problems.
Take take fire precautions.Keep a fire extinguisher near the job or some Baking Soda(Great for putting out small fires)
With the Bike idling spray a Volatile aersol around each one of the boots at the engine seal and then the Carb end of the boot.I use Carb Brake cleaner but domestic Hairspray works as well.
If the engine speed changes at all then you have a leak.
Sometimes you have to twist the boots onto the Carbs to get them to seat correctly and this is very important.I always fit the boots onto the carbs 1st and then tighten them.Then to the engine.Check also that the sealer O-ring in the Boots on the engine side has not been damaged or is too flattened to do it's job.If it is flat you can get away with using some Silicone gasket sealer to make a good seal.
If there are cracks in the boot you may be able to repair them using Crazy glue by spreading the crack,de-greasing it with Carb cleaner and drying and then pouring the Crazy glue in whilst spreading the crack then releasing the it.One of the boots on one of my CXs was done this way over 3 years ago and is still leak free
Also you can buy Spray Rubber,
http://tinyurl.com/6lddbu
I know a few CXers have used with success by taking off the boots,degreasing them and then sealing with the Spray rubber.
Note:If the boot ends have become hard I know of one guy who left the boot end in a pan of Brake fluid for over a week with the level just above the Flange and it softened then end good enough to take the brittleness out of the boot and make it re-usable.

