Ventured out to the garage with a recharged electric drill and made some "commitments"...

The round, 3" DOT legal tail light.  I think I will refinish the chrome ring/bezel in black.  You can see the issue with the tail section -- I've measured it many times, and it's not so much a twist, as a flaw in the original mould -- the LHS of the tail (in this pic) is "taller" than the right.  When the subframe is all welded up, some strategic application of heat might allow me to twist things a bit to compensate.

I decided to go with the DOT approve 4.25" headlight I am using with the xt supermono cafe racer.  I broke out the big hole saw and did some cutting.  The headlight will have to stick "out" from the fairing somewhat (typical of most endurance bikes) but it will be frenched in somewhat.  The used food container gives a sense of what it will look like.

Back to the Single

While waiting on a few parts and some milder weather...  the blizzard has kept us close to home on Christmas, so I set about the winter rebuild of the xt600 engine.

The process went as follows -- new (used) cases -- the latest model year that came with a kickstart -- 1990, I think.  Cleaned up at a transmission shop, old bearings removed, new bearings installed.  New xt600 cylinder with overbored piston -- .30 over, I think.  Starting to put it all together in the nice, warm inside environment...

The workstation -- a bit crowded, but it forces me to be disciplined and not leave tools and crap strewn about the place.  Ziplock bags are the greatest invention, as all the parts as removed are being put back into their place.

Case halves came together quite nicely.  Have a shopping list of new seals on the pink sheets, and since the photo I've installed the oil pump (with new o-rings), kickstart idler gear, and and kickstart spring mechanism.  Under all that went the shift detent arm and shifter.  Once I get the seals ordered (mainly the one for the balance shaft), I can finish the right side and start on the left.  New camchain will be installed as well.  I also plan to send the head off for a rebuild.  The cam journals look OK, so a valve job will suffice.  A very satisfying experience!

 Sketched some ideas out for numberplate shapes and headlight mount location.

Fabbed a steel tube exhaust mount last weekend.

 Having the mig welder handy saved a pile of time, but I am still not happy with the "looks" of the weld bead when it passes through the mig tack.  I am confident there is enough penetration, but there is just a bit too much material present to get it to flow nicely as the weld bead passes through it.

Exhaust

The Black Widow headers have been joined to a GPR half-system.  I tweaked it somewhat to bring it in closer to the rearset (although not close enough to melt boots).  I also fabricated an aluminum bracket -- however due to it's length it's a temporary fix as it flexes too much.  A more solid muffler hanger will be made from steel tubing.

Updates -- some new clothes!

Fairings mounted (still work to do), and gixxer pegs installed (after servicing).

For quite awhile I stuck with using an oxyacetelyne welder, as that is what I learned with, and I got pretty good at welding thin to medium-sized tubes and structures together.  Anything thick or something thick welded to thinner stuff, I left for someone with a tig-welder.  It made fabricating a bit tough, however, as you really need 3 hands to hold something in place, hold the torch, and dip the rod into the puddle.  Some creative clamping and use of magnets helped, but it was a pita.  Once an assembly was tacked, however, the finish welding usually went fairly well.
I later bought a cheap mig welder, but didn't bother with any gas.  I was forced to used flux core wire which led to tons of spatter.  It was fine to burn together metal that didn't need to look nice, but I never really trusted it from a structural point of view.
This past summer I got rid of the oxy bottles, and recently bought an argon/co2 tank to go with my little mig.  The idea is to use it to tack things in place properly, and then get the assembly properly tig welded together.

The main part I need to fabricate is the rear subframe.  I had some 4130 steel tubing left over from other projects, so after reading the specs on the dimensions of the ducati tail, I set about putting something together.  The cross-brace on the frame is 1.25", the square upper rails are 7/8", and the lower (assymetric) tubes are 1".  I've also added a rear cross brace towards the back, and the plate is to mount the new tank mount tab.  I want the seat to butt up against the tank, so the tank mount has to be "hidden".  Still some fabbing to do, obviously.

Another view.  When I cut off the old subframe, there was an elongated "hole" in the side of the frame, just below where the new subframe mounts are welded.  I cut some steel to fit and welded it in place.

Another view.  The lower frame tubes are purposely assymetric, to allow for the reseviour on the shock.  The upper rails are square, of course.  Again, only tacked in place, but it's sturdy enough to hold my weight as I gingerly sat on it to try it on for size.

As well I installed new connector blocks on shortened wiring at the front of the bike.  The LHS and RHS switchgear wiring were both about a mile too long so I got rid of some excess.  Here's hoping the bike still works when I plug everything in!