type spark plug: DR8ES-L
Electrode gap: 0.6-0.7mm (0.024-0.028in)
Tightening torque: 20Nm (2.0m-kg, 14.5ft-lb)
K&N part # KN-144 Seems to be a little better flow, and does catch a little more 'crud' Yamaha part # 1L9-13440-91-00 ELEMENT ASS'Y, OIL CLEANER Note that as far as I've been able to tell, all xs400's used the same filter.
1978 to 1981 DT-175 with CDI (no ignition points) spark plug gap .6-.8mm or .024-.032 inch, spark plug# B9ES
The valve clearance for a 1981 Yamaha XS400 is typically set at 0.10 mm (0.004 inches) for the intake valves and 0.15 mm (0.006 inches) for the exhaust valves. It's important to check and adjust the valve clearance regularly to ensure optimal engine performance and longevity. Always refer to the service manual for specific procedures and specifications.
It has a twin, four-stroke engine type and its displacement is 392.00 ccm. Its compression ratio is 9.2:1 and has Êan expanding brake. Fuel capacity is 17 liters.
From the user manual, 0.7-0.8 mm
If it's a 1981-83 with BP7ES NGK spark Plug use a 0.032 inch gap.
1978 to 1981 DT-175 with CDI (no ignition points) spark plug gap .6-.8mm or .024-.032 inch, spark plug# B9ES
Answer:Given the make and year, I would go with a 10W40 viscosity. I own a Chilton's Motorcycle Repair Manual (1959-1981) and in the Yamaha XS360-400 section is states "When the average air temperature is above 5 degrees Celsius (41 degrees Fahrenheit), use Yamalube 4-stroke oil, or SAE 20W-40, service rating SE or SF. When air temperature is consistently below 15 degrees Celsius (59 degrees Fahrenheit), use SAE 10W-30, service rating SE or SF."
The recommended spark plug gap for a 1981 VW Rabbit is .028"
The 1981 Honda 200 spark plug gap is .023. Most spark plugs will come pre-gapped from the spark plug manufacturer.
Which one?
81hp