[razerwire]

With the engine running you can use carb cleaner to find air leaks. Use the extension tube that comes with can so you can spray in small area. check gaskets, throttle shafts and so forth. Rise in R.P.M. shows air leak. You won't be able to get everywhere but will be a good start. Small camera with extension like some have referred to would help. Someone said they found them at home depot I think.