Hi Andy
Many thanks for getting back to me with the info very much appreciated, however, I was aware of the MC28 diagram, which was the reason for the question really.

Now I’m going to make some assumptions here so please be kind when shooting me down in flames LOL.

I assume there isn’t going to be any, if few differences between the MC18-21-28 Crankcases in terms of the Crankcase Bolt Torque values (probably my first and biggest assumption; sorry mistake).

The MC28 Crankcase Bolt Torque values seem to take a mean value of those given for the MC18 & 21. However, the MC18-21
http://nsr250.net/forums/members/nsr250r_manual_mc16_18_21/index.php#p=153 does not depict or mention the use of lubricant on either the Flange Heads or Bolt threads, is this a possible omission in the Manual?

If it isn’t an omission from the Manual, then taking the highest Torque value of the 8mm Bolts in the MC18-21 Manual of 2.5 kg-m (approx. 18.1 lb/ft, 217.0 lb/in; yes good old imperial measurements so you can tell how old I am) and applying a lubricant as in the MC28 Manual, then a reduction in Torque would be required.

I seem to remember in my Aircrafting days (too many years ago lol), applying a lubricant to a Dry Value Torqued Bolt would require a reduction to it’s Torque value between 15-20%. However, memory probably playing tricks or what! the dear old Internet says a lot more than that, it seems a reasonable accepted amount is 25%.

Therefore, applying a 25% reduction would bring the 8mm Torque Value down to 1.875 kg-m which is a fair bit lower than the 2.3 kg-m stated in the MC28 Manual.

Now I’m probably guilty of making life far too difficult here than its need to be LOL, but are the Torque values in both Manuals correct and HONDA just omitted that the Flange Bolt Heads & Threads had to be oiled?

Anyway that is the case for the defence LOL & closely monitoring any missiles coming my way!!

Take care all.

Regards
Philip