Honda ST1300A

Oil Change

Japanese Automotive Standards Organization JASO certified oil

special requirements due to the wet clutch and shear stability because of the transmission using the same oil.

The JASO designations are

Recommended oils on the ST-Owners forum:
Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil, 1 Gallon

Quotes from Mark Lawrence:

"Chevron Delo 400, Mobil Delvac 1300, and Shell Rotella are made from pure Group II oils"
"Three synthetics stand out from the rest: Mobil Delvac 1, Mobil-1 SUV and Shell Rotella T Synthetic."
(Courts ruled) "the word "synthetic" was a marketing term and referred to properties, not to production methods or ingredients. Castrol continues to make SynTec out of Group III base oils, that is highly purified mineral oil with most all of the cockroach bits removed." IOW, Castrol SynTec is not "synthetic oil" in the traditional sense, but "synthetic" in the marketing sense.

synthetic 80/90 every 10,000 miles. Funny that people call it the 'rear differential' when that's not what it is. It is a final drive gear housing.

Mark Lawrence: https://motorcycleinfo.calsci.com/Oil.html; founder or California Scientific (makes windshields)

Lower Cowl bolt
https://www.partzilla.com/product/honda/90106-MBY-000
$2.49 at PartZilla
5x12
part number 90106-MBY-000