Kohler — Fuel Conversion Procedure (Models with Fuel Block)
Adjustments · Fuel system
From a Kohler service manual covering: 12RES, 12TRES, 8.5RES. Check it applies to your exact model before use.
Applies to: Kohler 12RES, Kohler 12TRES, Kohler 8.5RES, Kohler CH20 engine, Kohler CH 740 engine
Before you start
- Explosive fuel vapors. Use extreme care when handling, storing, and using fuels.
Procedure
- Disable genset: master switch OFF, disconnect battery charger, disconnect battery negative lead first.
- Turn off fuel supply.
- Remove hose clamp and fuel hose from hose fitting in the fuel metering valve.
- Remove hose fitting from the natural gas outlet port.
- Remove plug from LP port; clean, apply pipe sealant, install plug into natural gas port.
- Clean hose fitting, apply pipe sealant, install fitting into LP port.
- Slide hose onto fitting and secure with clamp.
- For 12 kW models: connect DSAI leads together for natural gas (disconnect for LP).
- Connect and turn on new fuel supply; reconnect battery negative last; reconnect battery charger.
- Start genset and check for leaks using a gas leak detector.
Specs & values
- DSAI leads: connect for natural gas, disconnect for LP (12 kW)
- Fuel inlet 1/2 in. NPT
Full service-parts list: Kohler 12RES →, Kohler 12TRES →, Kohler 8.5RES →
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.