Cummins/Onan — Switching from petrodiesel to B20 on used engines
Maintenance · Fuel system
From a Cummins/Onan service manual covering: K 19, K1500E, K2000E, K38, K50, QSB 6.7, QSB3.3, QSK23, QSK38, QSK45, QSK50, QSK60…. Check it applies to your exact model before use.
Applies to: Cummins/Onan K 19, Cummins/Onan K38, Cummins/Onan K50, Cummins/Onan QSB 6.7, Cummins/Onan QSK23, Cummins/Onan QSK38, Cummins/Onan QSK45
Before you start
- B20 has a solvent nature and may clean the vehicle fuel tank and lines.
Procedure
- Install new fuel filters when switching to B20.
- Replace fuel filters at half the standard interval for the next two fuel filter changes.
- After the initial period, revert to intervals specified in the O & M manual.
- For EPA 2007 on-highway midrange engines, sample oil for the first 6 months to monitor fuel dilution.
Specs & values
- ASTM D6751
- ASTM D7467
Full service-parts list: Cummins/Onan K 19 →, Cummins/Onan K38 →, Cummins/Onan K50 →, Cummins/Onan QSB 6.7 →, Cummins/Onan QSK23 →
Source: Cummins/Onan 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.