The 12 pt head on the head bolt nearest the rear cylinder exhaust valve broke.
Fortunately it didn't seize and I was able to get it out.
Can I just replace the one bolt and re use the other 3?
If so where can I get just one?
Is it feasible to torque the head bolts down, then to swivel the cylinder into
position with the heads on it, then bolt the cylinder to the cases?
Of course I woulduse a protective barrier to avoid damage to the base gasket?
Thanks

 

You likely won't be able to buy just one head bolt. J&P Cycles has them for sale but you can only buy them in sets of 8. They aren't that much though. So it wouldn't hurt to buy the set of 8 and then have the extra just in case.

Your gonna have a real hard time getting the head bolts torqued down to 60 foot pounds with the jugs out of the bike. If it were me I would bolt the rocker boxes to the heads (not tightening them completely), then put the jugs on the bike tighten them all the way down. Then install the rocker box/head all together. Then make sure to go back and tighten everything down to torque ratings.

 

If one bolt has broken, you should replace all 8. The others will be in very similar condition, ie ready to break.
Good idea about bolting up first and swinging the whole barrel in, except the cylinder has to fit downwards over teh piston and there is not enough room in the frame.
Rear head has to have teh rocker box on, but not tightened,before head is slid in from the right. Front head can go in naked, then put the rocker box on.

Some pics showing how to do it, and how to make a torque wrench adaptor to torque the rocker box and head bolts in the frame is here:
http://xlforum.net/vbportal/forums/s...d.php?t=209347