Here is tip my father taught me. ALWAYS park motor on TDC. Couple good reasons. 1. Valves are closed so humidity will not rust valves or cylinder. This way water from rain or washing always gets to exhaust. Why have it sit there and potentially screw up your day. 2. Valve springs and valve seats will thank you. No tension and no corrosion. 3. When cold you already have it set up to check valve clearance Just a simple trick. Myself at races I always squirt a little oil in carb while idling and shut down. Set on TDC and load in trailer. Valves, piston have coating of oil and I feel better.