S90: Chain Adjustment

Couldn't quite wrestle the master link off the chain and decided to leave it for another day.  But at least I learned my way around the axle nut and axle adjusters.

At first I couldn't find the notches on the left side swing arm (you need to match marks on both sides so that the wheel is straight).  But turns out they were just under a lot of gunk.  A quick scrub with WD40 and a wire brush revealed them.


This is actually the right side markings, but you get the idea.

I also replaced the 6mm nut and washer on the adjuster bolt since they were a rusty wreck.  This picture is the entire assembly, though it doesn't show the shiny new hardware.

Rusty, soiled master link.  I'd pulled the clip halfway off already.

S90: A Tangled Web

The headlight had a weird screw with a "figure 8" slot.  Didn't know quite what to make of that, but decided to reslot it with the Dremel now, ask questions later.

I popped open the headlight cover, looked at the mess of wires, and then closed it back up.  A project for another day.

S90: Piston Out

Unfortunately, found the S90's cylinder was heavily corroded on the bottom where moisture (I assume) would have collected and sat.

Piston looked to be in great shape, though.

I did snap the oil ring while trying to get it off.  Not sure if that was me being too rough, or if it was just brittle with age.  Perhaps a little bit of both.

Also gave everything a nice scrubbing with the wire brush before reassembly.

S90: Main Jet Mystery

What's tough with this S90 is that if I see something that doesn't look quite right, it's hard to know if it's just supposed to be that way or if it's one of the many shadetree mods that the previous owner made.

All the carb diagrams I've seen seem to indicate that the Main Jet and the Needle Jet Holder should be two pieces.  But the one in the Keihin carb looks to be a single piece.  I've actually found it online and I think it's a more modern Honda type of jet.  Not positive, though.

The Workshop

S90: Clutch Continued

A full morning tackling the S90's clutch.


Stripped a screw on the clutch outer cover which meant I had to cut into the cover itself in order to reslot it.

Cut off the custom made hand-control-to-rear-brake cable.

The lock washer was completely torn up.

Not exactly sure what the gold welds are for yet.

A better look at the corrosion on the primary driven gear.

Was able to use the valve compressor and a wrench to remove the clutch screws.

Clutch and friction plates looked pretty far gone.

And it appeared that one of the friction plates had shed all its material at some point.

Killed one of the spring screws trying to pry it out.

S90: Clutch Cover Removal

All nine clutch cover screws were frozen, as expected.  The impact driver got 7 and I had to re-slot the other 2 with the Dremel.  Not too bad, considering how long the bike had been sitting.

Once I got the screws out, I was still having a lot of trouble prying off the cover.  Figured the gasket had fused it shut.  I yanked and hammered screwdrivers into the gaps for about 15 minutes until I finally realized that I'd neglected to take out one of the bottom screws (another lesson learned).

After that, the cover popped right off, but it wasn't very pretty on the inside.  I cleaned out the old oil sludge but I left dismantling for another day.