a carb is not a carb. there are differences. when ur buddy asked for a 38mm he should have looked for something like an FCR. the two stroke carbs have different designs.
not true. some are some arent. the carb on a CRF 450R is hooked right to the cable. it has to do with the carb, and nothing to do with what stroke motor it is. a sportman 400 will have the vacuum type carb, but will a TRX400? no. they are both four strokes but for totally different purposes.