The new TR1 motor - breaking stuff (part 6)

A friend once said: "There's no such thing as a free lunch" and "the best deals often come at some cost". Well, the TR1 cases are basically really nice (cosmetics aside), but had a sheared off bolt in one of the holes. Not the end of the world as you'd surely agree, but to be fair, I f*cked that job up pretty good. Which in turn gave me the opportunity for some lathe work. But let's do this chronologically.

Step one: You have a starter motor fixing bolt (M6) sheared off cleanly in a hole.

Left hand drill to the rescue. (Why I didn't try welding something on first is beyond me, guess I just love to suffer some times...)

Try heating up the engine cases before drilling in the faint hope that the left-hand drill will bite and just pull it out. 

More heat.

Mooooooooore heeeeaaat! 

Nope, didn't work, drill wandered off and then drilled the hole out oversized. Heli-coiled it, only to find out, I just set everything up for an M8-helicoil.

 Wound the coil out, put on my brain cap and machined a plug to go into the hole.

Polished the plug to 0.02 to 0.05mm oversize, with a slight taper on one side.

Test fit. 

Heated the cases to spit-hot. 

Put the plug in and gave it two good whacks with the ol' repair-hammer and there you have it. 

Second thing I wanted to do was to make a drill-jig for installing the oil-pressure sensor. As the last one was slightly off center, I decided to make an even more advanced jig with a little locating lip.

That's the boss that Yamaha kindly cast into the cases, but then decided never to use. It's not present on newer (e.g. Virago 1100) cases. 

And there you have it. 

It'll be a bit until you actually see this one in action, as the order of posts on the blog doesn't exactly depict the order of events anymore, i.e. this happened before all the cleaning and sandblasting.