Complete gasket set with crankshaft seals and valve stem seals for Onan P216, P218 and P220 opposed twin cylinder engines, covering the parts in Onan gasket set 168-0187. Also fits the B43 and B48 of the same family and the later replacement engines OL16, OL18, OL20, LX720, LX770 and LX790. This set does not fit the P220G-OHV V-twin, which is a different engine sharing only the model designation; if the valves are in the cylinder head rather than in the block, this is the wrong set. Seventeen pieces per set. Includes crankshaft seals for both ends, one for the timing gear cover at the front and one for the bearing plate at the rear, which are different parts. The valve stem seals are intake only, one per cylinder: these engines run the exhaust valve without a stem seal by design. Check the head and block surfaces for flatness before reassembly and inspect the valve guides, since a worn guide will quickly ruin a new stem seal.
- FITS ONAN P216, P218 AND P220 opposed twin cylinder engines and the B43 and B48 of the same family. Replaces the parts in Onan gasket set 168-0187. Also covers the later replacement engines OL16, OL18, OL20, LX720, LX770 and LX790, which share this bottom end. A complete gasket set is what a full teardown needs, and doing it in pieces means finding out mid-job which one you are missing.
- DOES NOT FIT THE P220G-OHV V-TWIN. Read this before ordering. Onan used the P220 designation on two completely different engines: the opposed twin flathead covered here, and a later overhead valve V-twin that shares almost nothing with it. Look at the engine, not just the tag. If the valves are in the head rather than in the block, this is the wrong set.
- SEVENTEEN PIECES, including both crankshaft seals. The front seal sits in the timing gear cover and the rear in the bearing plate, and they are different parts. Both are consumables that should never go back in after a teardown, and both are separately ordered items on the factory gasket set, which is exactly why people find themselves short.
- THE VALVE STEM SEALS ARE INTAKE ONLY. These engines seal the intake valve and run the exhaust valve without a stem seal by design, one per cylinder, so a twin uses two. That is not an omission in the set, it is how Onan built them. Blue smoke on startup and after a long idle is what a hardened intake seal looks like.
- WHILE IT IS APART. Check the head surfaces and the block deck for flatness with a straightedge, look at the valve guides since a worn guide will destroy a fresh stem seal within a season, and clean every sealing face down to bare metal. Torque the heads in sequence and in stages, and set valve lash to your engine manual on reassembly.