I mostly hang out on the RSR Forum but need some help so I thought I'd try here too. I'm getting a lot of good suggestions there but thought someone here might have some different ideas. I've tried looking around for threads on this topic, but don't seem to find any, which is odd because there are a number of threads on it in the RSR Forum. So I must be missing them here.
I was out riding a couple weeks ago when my '02 RS backfired a couple times as I was pulling up to a stop and it died. After about 15 minutes of trying, I finally got it started again, but it was only firing on the rear cylinder. Since then I've put Seafoam in the gas tank - no help. I put brand new plugs in - no help. I've ohm-ed out the coils and plug wire boots - no help (they're all within specs). Intake manifold does have two cracks but I've sealed them with RTV sealant and they don't appear to go all the way through anyway. This weekend I plan on ohm-ing out the pickup coil to make sure that's ok. I've also got a known good used CDI box coming to try out. I've checked in the dark to see if my coils are arc-ing to the frame and they don't appear to be, although I think I've gotten shocked a few times over the years when my knee has touched my billet air filter cover. (So I'm still looking into the possibility of arc-ing.) I do have good spark going to the front cylinder. I'm assuming fuel and air are getting there since both cylinders are fed by the one carb and the rear cylinder is firing fine. I do also have compression to the front cylinder and my decompression solenoid seems to be working properly. When I rev the motor, it is backfiring about every 3rd stroke. Doesn't backfire when idling. Any ideas/suggestions are greatly appreciated,

Wayne