1968 Li125 S

Getting it running

I started by checking the usual trouble spots for a bike that has been sitting for a while.

  • I checked the spark by removing the plug and grounding it to the engine block. When the engine was kicked over the result was a nice fat blue spark - no problems there.
  • The fuel system still had gasoline in it but it had been standing for years so I drained the tank and cleaned the carburetor.
  • When I was kicking it over it felt like it had no compression. My father and I decided to remove the barrel and see what was wrong. Everything looked OK until we got all the parts under the light. The exhaust port was about 50% filled with crud as shown below:

The piston also looked fine from a quick view from the open barrel but we decided to pull it to be sure. On closer inspection on the workbench we found that the piston had somehow completely lost the first piston ring and a large part of the crown and side was missing. There were also large scores down the side of the piston, particularly at the exhaust port side where I assume the piston chunk and rings shot out the exhaust. I have no idea how something this destructive might happen in a working motor but the results mean a new piston and a rebored or rehoned barrel.

Needless to say, it might take a while to get this bike running. On the brighter side, it looks like none of the destruction that happened in the barrel managed to blow by the piston and find its way to the crank and the main bearings.

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