Kohler Ford LSG-423 — Compression Test — Compression Gauge Check
Testing & diagnosis · Engine
For the Kohler Ford LSG-423, from the Kohler service manual.
Browse Kohler generators & specs →
Procedure
- Operate engine at least 30 minutes at 1200 rpm or until normal operating temperature; turn ignition off; remove all spark plugs
- Set carburetor throttle plate and choke plate in the wide open position
- Install a compression gauge in No. 1 cylinder
- Install an auxiliary starter switch; crank the engine (ignition off) at least five compression strokes and record highest reading
- Note approximate number of compression strokes required to obtain highest reading
- Repeat test on each cylinder
- Indication is normal if the lowest reading cylinder is not less than 75 percent of the highest
- If one or more cylinders read low, squirt approximately one tablespoon of engine oil on top of the pistons and repeat
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Lowest cylinder must be at least 75% of the highest
Source: Kohler 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.