Sometime ago (in November) I posted that my 750 was backfiring from the right pipe on closed throttle decelleration, the dealer said it was normal for a 750 to backfire to some degree, but mine had not been backfiring since installing coasters and adjusting the carbs, it wasn't there one day then there the next, and why only from the right pipe? Anyhow I went for a ride today and finally figure out the cause of the backfring. The front exhaust manifold gasket has a leak or the manifold is cracked but I'm not sure which item is faulty but I can hear the leak there with my mechanic stethoscope. Since it's still under warranty(extended) and I complained about it before the factory warranty expired this past Dec. it should be repaired under warranty, in any case I don't care because next month it'll belong to them, my new 900 is coming in. I thought that I'd post this info in case a 750 owner has a similar concern, it may help you isolate the cause alot faster.