STO valve stem oil seals in motorcycle

STO valve stem oil seals in motorcycle.These vital seals must keep oil inside the engine while coping with the crankshaft's rotation and heat expansion.Rear main seals come in many shapes and sizes, but all are responsible for sealing the back of an engine's crankshaft.
Once-piece Seals
One-piece seals are the best at sealing but require a specially machined crankshaft and cannot be replaced without pulling the crank.STO valve stem oil seals in motorcycle.
Many older engines used "rope" seals that resembled a piece of cord. These rope seals did a decent job of keeping oil pressure in the engine but would eventually become saturated and start to leak.
These plastic seals are an improvement over rope seals but are still prone to leakage. STO valve stem oil seals in motorcycle.These seals are often used because they do not require removal of the crankshaft to replace.
Older seals may leak due to heat shrinkage, damage and pitting, defects in the crankshaft, improper installation or clogging of the Positive Crankcase Ventilation system (PCV).
Rear main seals are located at the back of the crankshaft, at the rear of the engine block. STO valve stem oil seals in motorcycle.Many of these seals can only be installed or replaced by removing the rear crankshaft main cap.