1970 Velocette Thruxton recommissioning

 Got a few more hours to work on the Thruxton today.  There were a couple of things that had caught my attention as I learn about Mark's bike. The crash had damaged the clocks and mounting brackets. Not terrible damage but enough to skew things out of alignment.  The most puzzling thing to approach was the speedometer; one of the mounting bolts had been pushed in, bending the housing in as well.  

My first thought was to sent the speedo out to Joel Levine in Georgia to have the housing fixed. The tach was sitting in a box from him and had paperwork stating that it was repaired and calibrated by in 05'. However, the budget isn't quite able to handle that luxury and with the proper procedure I might be able to get reasonable results.

The first natural thought was to put something on the mounting point stud and bent it back. Meh, yeah, the thought of it snapping off and munging up the threads didn't seem worth it. If it didn't break, it certainly might loosen the stud from the housing and I was fairly confident that the housing would be think enough to resist being bent back in such a short attachment point. Heat was out of the question; so was removing the bezel to access the dent from in side.

The last thought that came to mind was to use the the stud to pull the dent back up and out. Much like the 'weld on' tabs used for dent removal.  After digging though the most accessible thick pieces of small steel sections with pre-drilled holes, I found a small flat prybar with a hole. It seemed reasonably thick enough for the job and just fit within the space of the clockworks mounting screws and it was able to catch the edge of the speedo case. The thought was to use the edge to support the "tool" and draw the dented down bolt up towards the tool.  - nothing ventured, nothing gained?

With a 8mm deep socket and a 1/4inch tee handle, the nut was tightened up and then, tightened some more. It all felt like it was working ok, the final moment was to remember to STOP when it got too tight. NO need to break the dern stud right out. Perfect, it's all worked well enough that it is almost not too noticeable and probably won't bee seen when attached to the brackets.

The second part was to straighten out the mounts for the tach and speedo (also bent). Those took a little more time as the bends went everywhere. The last bit was closing up the angled base to orient the gauges and to get them to lay relatively flat. 

Moving on to the timing chest, I found a few small things to attend to;  one of the push rod tube studs was loose and coming out with the nut, the new timing gear was striking the inside of the engine case and one of the support plate oil jet nuts was fouling the timing cover (testing without a gasket)

The stud was an easy one,  just take it completely out, lock the lower section in a vise with soft jaws so as not to ruin the threads. Take the nut off then double nut it to reinstall in the case.  One more problem solved. The next was to address the timing gear.  This engine came as a coil ignition model and had been retained as such; the coil was still attached to the under tank mounting bracket. However the Lucas distributor had been lost to time and shuffling around. To convert it to manual advance magneto requires a few steps and extra parts.  The distributor style gear did come with the bike but this gear has a reverse taper to that of the manual advance gear. [picture to follow]

With the magneto temporarily installed a test showed that the gear scrapes the inside of the engine case.

Ok, we can fix this, off to the hobby lathe for a little facing.  after a few light passes and some light needle file work, the gear was working out just fine.  The gear also needed a touch of fitting onto the taper of the magneto. Experience from the past told me that if you lap a tapper joint the depth changes. So with only a very fine polish was the taper setup to the point that when you lightly tightened the magneto center nut, the taper would need a puller to remove it. 

While on small tasks, the lower magneto retaining bolt was hard to reach. This is typical on almost all Velos. In the past I've made a few wrenches that worked fairly well. With the Thruxton, the access is hindered by a breather tube just below the mag body. It looked as if you can easily reach (relative) this nut from below the left side of the engine; just about the trans. Fast forward a few hours and presto, a new tool to add to the kit. Made from 3/16" thick 1" stock, the wrench was cut, bent, heated cherry red and dropped into quenching oil.

The rest of the time was spend on reassembling the timing gear and steady plate; checking over anything in this area before the final reassembly.  One issue was that the cover was rocking side to side with a significant gap. Even though I was not using a gasket with this fitting, I expected less of a gap. The nuts that hold the oil jets were a tad proud, holding the cover open. With a little file work and light sanding I reduced the gap, not quite to zero, but close enough that the usual gasket will take up the slack. Next task is to shorten up some socket head bolts to replace the screws normally used to hold the timing cover on.

all for now...