One of the small pins that prevents the piston ring from rotating fell out or broke off. It scored the piston and the cylinder was spit out (didn't lodge and seize the engine). It also left a hold in the piston where it was press fitted into the piston. The piston rotated and the ends snagged a port and the rest is obvious.
I'm not sure if the piston and pin were defective or if the pin was not inserted properly. I already pull apart each engine before installation and checking these piston pins will be another check I will perform.
If the pin can be removed with pliers, I will reinsert with a touch of JB weld to keep them seated.
The engine was a bushing Dax and has a little over 1 year use of use on a bike I built for someone. The owner doesn't abuse his engine and rarely exceeds 12mph on his 55 tooth sprocket geared bike. Its an easy fix, I have a spare cylinder and a new piston and rings are 30 bucks from Dax.
later!
I'm not sure if the piston and pin were defective or if the pin was not inserted properly. I already pull apart each engine before installation and checking these piston pins will be another check I will perform.
If the pin can be removed with pliers, I will reinsert with a touch of JB weld to keep them seated.
The engine was a bushing Dax and has a little over 1 year use of use on a bike I built for someone. The owner doesn't abuse his engine and rarely exceeds 12mph on his 55 tooth sprocket geared bike. Its an easy fix, I have a spare cylinder and a new piston and rings are 30 bucks from Dax.
later!
