I recently acquired an abused 1995 Virago 535 with 23,000 miles on the odometer; the motorcycle up till now has had excellent performance with good acceleration. When the engine was hot and under stress the bike began making popping sounds (like metallic sounding explosions). I noticed cracks in the rubber joints between the carburetors and the cylinder heads. I could feel drawing and sucking through the fractures so I patched the breaks with silicon and waited 24 hours for the patches to cure. After the repair and during testing the popping sounds had disappeared however so did the performance. I could not make the Virago accelerate nor would it run over 45 mph however the motorcycle would start easily. What do you think the problem is? The air filter is new and no other adjustments were made.