Replacing the cylinder base 'O' ring with a new genuine Yamaha replacement is essential during the course of an engine re-build.
Specifying genuine Yamaha gaskets, seals and 'O' rings means fitting the same parts used by the Yamaha factory professionals!
You may be interested in: 3YF1118100 (cylinder-head gasket) 3YF1135100 (cylinder base gasket)
Our pro-workshop gasket sealant, 08C70K0234M to complete the job like a professional!