possible '78 wing purchase

imported post

For starters, if it looks like it has been stored outside---rust, faded paint, etc., walk away from it. You will have nothing but problems.

Assuming it passes that test, look for:
-cylinder compression. If you can't test compression, see if you can at least pull the spark plugs. They will tell a story.
-look for rust perforation on the frame under the engine, especially the centre stand pivot.
-mufflers will usually rust out underneath, where the exhaust pipe joins the muffler.
-put bike on center stand and check for run-out on both wheels. Make sure they are straight.
-open the side cover on the left side of the fake gas tank. See if the wiring has been butchered or if it looks intact.
-Open oil filler cap and look for white milky stuff inside. It means the antifreeze is leaking into the oil.
-look under the bike, on the garage floor after it has been parked overnight. Even a few drips of oil or antifreeze on the floor means it could be leaking through the weep hole which means the water pump seal is shot--a big job to fix.
-inspect frame carefully for cracks, dents or welds.
-watch the voltmeter while the engine is running. It may drop a bit below 12 volts at idle but should easily climb to 14 if you rev the engine a bit. If not, then probably alternator or regulator problems
-turn the kill switch off and crank the engine for about 10 seconds. Make sure it will still crank strongly. Otherwise, battery is likely weak.
-look for corrosion in battery compartment.
-check that speedo and tachometer both work and that the needles don't bounce around. Look for water droplets or misting on the underside of the glass.
-see if the rear shocks are the factory originals. If so, they are shot and you will need to replace them. About $200
-If possible, inspect the inside of gas tank for rust.
-check that neutral light works. If not, it is a PITA to fix.

-watch the exhaust while engine is running. Blue smoke means bad piston rings or valves, black smoke means carb problems, white smoke with a sweet smell meansblown head gasket or worse.