I have a 98 sportster 1200, with 15k miles on it. My carb recently blew so my mechanic put an S&S shorty carb on it. Ever since my bike, every now and then a popping sound will come from the bike and the power will cut for 1/10th a second. Additionally, the oil light comes on every now and then for about 15 seconds then flickers off, and usually a blip of the throttle will make it turn off. It looks like there is a little bit of oil condensation on the inside of the carb cover and yesterday while riding the bike started making a loud panging type sound in tune with the engine , I pulled over, it sounded like it was coming from the air cleaner. I waited 2 minutes, started the bike again and the noise was gone. Any ideas whats going on with my sportster?

 

tried to identify exactly where the clanging noise is coming from, but I couldn't get the bike to make the noise long enough when it did. It also seems like the oil light is coming on more frequently. I tried checking the dipstick but I can't get it to unscrew or come loose, thinking maybe the silver part of the thermometer is stripped.