Q: What is the purpose of checking the tightness of the throttle body mounting bolts every 7500 miles?
A: To avoid the occurrence of a vacuum leak, it is required that you check the tightness of the throttle body mounting bolts every 7500 miles. Should you suspect there might be a vacuum leak between throttle body and intake manifold, then get a length of pipe with the same diameter as fuel hose. Start the engine while placing one end of this pipe next to your ear and use another to feel around the base of your throttle body. There will be a hissing sound if there is any leakage. Remove air cleaner assembly. Caution: When removing air cleaner, ensure that no foreign objects fall into the throttle body. There are two mounting bolts in side cylinder head and one mounting stud and nut on right hand side of cylinder head flange. Check all three for proper torque tightening. Tighten those bolts evenly should they have loosened up but do not overtighten so as not to strip threads on aluminum casting throttle body. If tightening these screws doesn't solve the problem, then disassemble throttle body for inspection purposes only Vacuum leak continues after tightening down mounting bolts- remove top cover from crankcase just above carburetor throat again for closer examination Reinstall air filter cartridge after performing maintenance on vehicle.