Hello. New to this forum and sledding, but pretty mechanical. I have a 1998 Polaris Indy 500 Classic, Sled has been running great until last weekend. Was riding around 50 mph when I lost spark, (CDI module wires burnt at box) sled backfired pretty good. I replaced the CDI box with a new one, replaced plugs, NGK BR8ES gapped to .028. Sled starts fine, but will not accelerate at all, just bogs down, and backfires occasionally. I've got good spark to both plugs. Hope someone can help. Thanks. Gary