2549,
Just went through the same thing with a bolt head mark of "7" on a JD790 (see pic) here's what I found........The JD Parts Catalog called out a M8 X 25, Class 10.9 Flange Bolt for my application. Metric Bolt Torque Chart you would think the torque should be should be Lubricated 23.5 lb-ft and Dry 29.5 ft-lb but hold on, the bolt head mark "7" indicates the bolt meets Japanese Industrial Standards (JIS) of which I found yet another chart (attached) on this site indicating a torque range of 17.4 ft-lb to 20.2 ft-lb.
I sent an email to Yanmar asking for clarrification and they said to contact JD since that engine was made for JD applications, send an email to JD asking for clarrification and they said to inquire at my local JD Dealers and hence a response from my local service department: "Correct torque is 26 ft lbs". :confused2: