older bard f 81 oil furnace. Replaced the blower motor atop the squirrel cage, but could not locate original motor. Advised to use next larger size as is compatible 4 worked for about 4 weeks, but now my circuit breaker trips. I reset, turn on boiler, manually spin belt/pulley and it works then, but when room reaches desired temp, the circuit fuse at the main fuse wall dedicated for the furnace.