I have several problems that I think are related. I follow the 3 min, 3 mile warm up faithfully with my ride. (1998 FXSTS) Lately and it's happening more and more, I am getting backfires on acceleration (only after I close (push in) the enrichener), on deceleration and at times just in normal cruising. The acceleration backfire is coming from the carb and rarely is heard in the pipes. The deceleration is for sure in the pipes. In normal cruising at times it is just like a major cough... almost like it's getting no fuel for a minute. I also get this sensation at times that I'm not firing on both cylinders. Under major acceleration however, it doesn't backfire once I get to the power curve (don't know how else to explain that). At least if it does it's very rare. Also including the acceleration backfire it is constant at take offs from stand still unless I up the revs prior to releasing the cluthc. (Sure don't like doing that!) I have cleaned the plugs... then installed new ones day before yesterday gapped at 40. I have read something about working with the carb but don't know how to do that. I believe the air/fuel mixing screw is sealed with an alluminum cap. Would like to know how to do this if it is practical. My ride is a 1998 FXSTS with just over 11,000 miles. I bought it second hand in China (that's where I live and ride so dealers are hard to come by. To my knowledge there is only one in Beijing with a branch in Shanghai. I live far from both of those places.) so I am not sure if the carburetor is stock or not. Nor do I know how to tell. It does look like what is in my service manual though. My pipes look normal but I know they have nothing inside. This ride is loud! I have been wanting to check my timing thinking that may be part of the problem since the bike rides "hot". I feel it is much to hot at the end of a ride... but then I have read that could be caused by to lean a mixture at the carb. I have tried and tried to both find and/or make a sight glass for the timing hole but no luck so far. I have also read a person can test for leaks with carburetor cleaner. Don't have any and sure don't know where to get any here. Is there something else a person can use? I know this is rather lengthy but I would sure like to get this delima taken care of. I fear this backfiring is not doing much good to my ride! Since buying this machine I have changed the fluids, adjusted the clutch, installed a new clutch cable I waited for one month to receive from the States, adjusted the primary chain to 3/4" play and loosest point, adjusted the hex bearing retainer and the fall away on the front wheel/fork, checked the oil pump with a clear flexiline to make sure oil was pumping into the tank and torqued all nuts and bolts to service manual specs. I think I get around fairly good with the maintenance as long as it's not major overhaul so if anyone can point me in the right direction with this back fine issue I would be most greatful! Thank You and cheers!