S90 Exhaust

I cut off the mount from the white piece, leaving plenty left over. I'm hoping to get some practice in with my new wire welder before I do this for real.

So long, rest of the metal. Maybe someone wants you, somewhere else...

Trying to find a place I can measure from.

This is after grinding and wire-wheeling. I don't trust my welding skills much, so I may add a piece of steel as a backing for the joint.

S90 Exhaust mount

No wonder this S90 project was so cheap to acquire. There was a title, but the motor arrived as a box of rusty bits. I was fine with this, but I noticed a few months ago that the exhaust mount was sawn off. Not only was it gone, it looks like somebody drilled a bunch of holes to make the cut. (Also, the battery cage was all cut up, but I'll get to that later.) The things people do to these old bikes...

Anyway, I found the right piece of the frame on the Ebay. It was nice not having to get a full frame shipped. Also, I verified that the single-hole muffler mount was the right one via this site, which is the best resource for all the weird/stupid changes the S90 went through over its life cycle.

In order to make sure I weld it up in the correct place, I made a jig out of two pieces of angle iron. Once I weld them together, I'll have the alignment triangulated for these three points: swingarm hole, centerstand hole, and exhaust hole.

Motor unfreezing

Last weekend I fabbed up this tube steel jig. The threaded rod matched the size of my largest tap - 1/2 with 13 tpi. I put a chunk of aluminum flashing under the rod so it wouldn't dig too much into the piston.

I still need to make a guide of sorts to go inside the cylinder so the rod doesn't walk, pulling the cylinder studs over. For now, the combustion chamber is soaking in a puddle of Kroil.

I don't care too much about this cylinder as there are broken fins, but it's good practice if I have one that I do care about come through...

Here you can see the two nuts and a washer I used to turn the threaded rod. This works ok, but it's too long and tends to slip under high torque. I'll probably end up cutting off a short chunk of the rod and just welding the nut onto it.