Welcome Home 1980 Yamaha XS850SG!

On September 19th, I purchased a 1980 Yamaha XS850SG off of CraigsList for $550.  When I got it, the bike ran but had a few small problems.  The electrical starter did not function and the bike would only kick start.  The kick start was very, very difficult to operate.  The brakes had very little stopping power.  The tires were at least three years old.  The right side petcock leaked fuel.  There was probably gas in the oil (yes, after checking, it was half gas, half oil).  The bike seemed to be running a little rich.  Both brake master cylinders had seen better days.  The tank had been poorly repainted at some point.  The original Yamaha and Special badges on the tank and plastic covers were missing.  The electrical guts of the bike were in a plastic bag behind the headlight.  One good thing that came with the bike is a full set of touring luggage.  Nice!

This particular XS850SG can best be summarized as being a fast, dirty, dangerous bike.  In other words, the visceral experience every 13 year old gear head dreams of.

Note that posting this was delayed until the title cleared.  Now that the title is in my possession, welcome home XS850!

The priority list to repair these defects is as follows:

  1. Petcock replacement – DONE
  2. Brake master cylinder replacement (both front and rear) – Postponed.  Can be ridden safely as-is.
  3. Brake line replacement (with stainless steel braided lines) – Postponed.  Can be ridden safely as-is.
  4. Brake caliper rebuild and possibly replace old brake pads – Postponed.  Can be ridden safely as-is.
  5. Electrical system rebuild/repair (including fixing the electric starter, removing strange the 120 volt battery charger, and installing a Battery Tender Jr pigtail plus most likely replacing the fuse block with something modern) – DONE.  Fuse block replaced with blade fuses.  Battery Tender Jr. installed in place of strange 120 volt battery charger.  Electric start works now that petcocks are fixed.  Kickstart also works.
  6. Replace oil (engine, middle, and final drive oil) – DONE.  Used 85wt gear oil for middle and final drive.  Used 15w40 Shell Rotella for engine.  Replaced filter, too.
  7. Re-badge tank with something interesting (used to say Yamaha on the tank and Special on the plastics) – Still thinking what I want to put on…
  8. New tires (rubber is at least 3 years old) – Postponed.  Can be ridden safely as is.
  9. Replace spark plugs – DONE.  Iridium plugs now installed.
  10. Voltage meter to monitor what the charging system is up to – Postponed.  Can be ridden as is and bump started if needed.

Other things I will consider doing in the future are:
  1. Replace fork oil and possibly rebuild forks – Fork oil replaced with ATF.  No need for rebuild now.
  2. Fine tune carburetors and verify that the bike is not running too rich – Going to see what the mileage is like first before tinkering with carbs.
  3. Replace handle bar controls – Okay for now.  Looking for a rotary switch to use as engine kill switch.
  4. Add alarm system (the handlebars do not lock)
  5. Re-paint fuel tank and plastics
  6. Polish all chrome and aluminum
  7. De-baffle muffler and rebuild airbox for more air flow.  This will require re-jetting the carbs or replacing with a set from an XS1100.  Could also fuel inject if I upgraded the electrical system.
And now for some obligatory bike photos.  Better pictures will come later.

I test rode and purchased the bike at around 10pm.  I’m thinking this one might need to take the name of “Midnight Special.”

 The chain is for security.  Don’t want anyone getting ideas.

 

Triple exhausts for the triple inline engine.  Also dual horns that are pretty loud.  Note that the engine is air and oil-cooled.  A rather interesting design.

 The petcock in the middle top of this photo is leaking gas onto the air box.  It will be replaced soon.

 Yes!  It has shaft drive!

 

55433.5 miles on the odometer.  The speedometer does not go high enough based upon how fast this bike can go.  On the test ride, I accidentally took it to 80 mph in 3rd gear (without reaching red-line) and popped a wheelie.  This thing is hella fast.