Ring jamming and rotation obstructions

Sealing problems often occur when the rings on four-stroke 
engines can not move freely in the ring grooves. This inevitably 
causes damage on the pistons and cylinders (overheating and 
piston seizures). Keystone rings are less prone to ring sticking or blockages 
in the ring grooves due to their shape.

Reasons for ring blockages and ways to prevent them

• The rings must not clamp axially in the groove. The  evenness of the piston rings must be guaranteed. Take care  not to bend the piston rings by pulling them onto the piston  incorrectly.
• The dimensions of the ring groove must match the piston  ring.
• The ring grooves must be free from dirt and other deposits  (Fig.1).
• The engine oil must meet the specifications stipulated by  the engine manufacturer. Incorrect oil promotes the  formation of carbon deposits and ring sticking in the  grooves.
• Operation of the engine with vegetable oil and alternative  fuels.
• Bent connecting rods and consequent skewing of the  pistons in the cylinder bore.