It has been suggested in Mick Walker's Twins and Triples book that there have been an excessive number of breaks in crankcase studs.  This is apparently ue to incorrect torque figures being used.  It is not advised to exceed the official figures giuven in the workshop manual for each model.

The 650 manual I have, dated January 1998, lists 1.2 Kgm/12 N.m for M6 threaded crankcase studs, and 2.8 Kgm/27 N.m for M8 threaded studs in the back of the manual, with a slightly lesser figure of 1.0 Kgm for the M6 studs elsewhere in the book.  The slight difference between these two figures should have little negative effect, at least in my limited non-mechanical opinion.

Crankcase Studs

© Steve Carr, 2001-2007

Site created February, 2000.  Last modified Friday, May 15, 2009

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Last updated
30 May 2005