Generac — Piston, Rings and Connecting Rod Assembly
Repair & overhaul · Piston and connecting rod
From a Generac service manual covering: GN-190, GN-191, GN-320, GN-360. Check it applies to your exact model before use.
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Before you start
- DO NOT USE A WASHER WHEN ASSEMBLING THE ROD CAP.
Procedure
- Install the rings using a ring expander; install the oil ring assembly first.
- Install the second compression ring with its inside chamfer facing up.
- Install the top compression ring.
- Assemble the piston, rod and wrist pin with the assembly mark toward the engine flywheel side.
- Coat the wrist pin and its bores with clean engine oil.
- Install one new snap ring into the piston's wrist pin bore.
- Assemble the piston to the rod with the assembly mark dimple opposite the match marks.
- Slide the wrist pin through and install the second snap ring to retain it.
Tools required
- Ring expander Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Assembly mark must face flywheel end (3:00 position)
- Use new snap rings when reassembling
Source: Generac service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.