Cummins/Onan — Valve and Injector Adjustment - STC or HVT OBC
Adjustments · Valve train
From a Cummins/Onan owner's manual covering: K 19, K19, K19 Series, KTA19, KTTA19, Kt19. Check it applies to your exact model before use.
Applies to: Cummins/Onan K 19, Cummins/Onan Kt19, Cummins/Onan K19 Series (KT19/KTA19/KTTA19) engine, Cummins/Onan KT19 engine, Cummins/Onan KTA19 engine
Before you start
- Do not use a clicker-type torque wrench for OBC method.
Procedure
- Steam clean engine.
- Run engine in retard mode before setting OBC method.
- Disable STC oil control valve.
- Operate engine at high idle 5 minutes in normal timing mode.
- Remove rocker lever covers.
- Rotate engine to set marks.
- Adjust crossheads, then valves.
- Tighten injector adjusting screw to 10 Nm [90 in-lb] using OBC method.
- Tighten locknuts to specified torque.
- Install rocker lever cover.
Tools required
- Dial type torque wrench with 0.28 Nm resolution and 17 to 23 Nm range
- ST-669 Torque Wrench Adapter Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Intake 0.36 mm
- Exhaust 0.69 mm
- STC OBC adjustment 10 Nm [90 in-lb]
- Locknut with adapter 45 Nm [35 ft-lb]
- Locknut without adapter 60 Nm [45 ft-lb]
Full service-parts list: Cummins/Onan K 19 →, Cummins/Onan Kt19 →
Source: Cummins/Onan owner's 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.