Web Log

Our Camper Van




Amy's Cakes

Outboard Hydroplane Racing

Radio Controlled Toys

1979 Yamaha SR500

1979 Yamaha SR500

My daily driver/beater.


My father purchased this bike new in 1980, and would give me rides on the back when I was little. In 1993, when I left for college, I bought it off of him for 500$ with only about 1500 miles on it.

Since then I have had to rebuild the engine twice, once because the carberator came loose, the engine ran lean, and siezed the exhaust valve on the freeway (Excitement!), the second time because I mis-measured the piston-intake valve clearance when assembling it with a higher-lift cam and high-compression piston. It is running quite well now, however, putting out about 1.5 times the stock HP, and is quite peppy around the city, though the top speed is pretty-much unchanged.

Soon after the first rebuild the the kick-start ignition coil went out on the stator. A rebuild was a few hundred bucks, a new replacement from Europe (where the SR500 was sold till the 90s) was about 600$, so I chopped the coil open and re-wound it myself with some 37 gauge magnet wire (took many movies worth of mindless winding).

The stock muffler was rusting out, and VERY heavy. I purchased a basic replacement from JC Whitney, but it cannot keep the packing in it for more than about 200 miles, so it is extremely loud most of the time. I am still looking for a good solution here.


  • 540cc cylinder sleve & 11:1 compression Weisco Piston
  • Megacycle Cam (just takes 1 :)
  • High flow aftermarket pipe (LOUD, won't keep packing in it for more than 200 miles)
  • K&N Pod air-filter
  • K&N crankcase breather filter
  • Galfer SS brake lines
  • Drag bars & Bar-end Mirrors
  • Oil cooler
  • Thermometer dipstick
  • Tossed battery & battery box, replaced with large capacitor