Cummins/Onan GTA38 / GTA50 — Carburetor - Remove and Install
Repair & overhaul · Fuel system
For the Cummins/Onan GTA38 / GTA50, from the Cummins/Onan owner's manual.
Applies to: Cummins/Onan GTA38 engine, Cummins/Onan GTA50 engine
Before you start
- Cap-screws threaded into aluminum may require torque reductions of 30% or more.
Procedure
- Disconnect battery power; turn off and tag manual gas shut-off valve.
- Loosen 2 in pipe coupling below RV91 regulator; disconnect ASCO valve.
- Remove band clamp from turbocharger inlet and carburetor outlet pipe.
- Remove carburetor air/fuel outlet pipe (six 1/2 in bolts); do not reuse gasket.
- Remove RV91 regulator from carburetor with a 15 in pipe wrench.
- Remove 600D carburetor (four 1/4 in and six 3/8 in bolts).
- Install 600D carburetor; 3/8 in bolts to 24 Nm [18 ft-lb]; 1/4 in bolts to 7 Nm [5 ft-lb].
- Install 2 in inlet pipe with pipe sealant; tighten one full turn.
- Install outlet pipe and gasket with silicone sealant; six 1/2 in bolts to 53 Nm [39 ft-lb].
- Install band clamp on turbocharger inlet hose.
- Reconnect coupling and battery; open manual gas valve.
- Check all fittings for gas leaks.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 3/8 in bolts 24 Nm [18 ft-lb]
- 1/4 in bolts 7 Nm [5 ft-lb]
- 1/2 in bolts 53 Nm [39 ft-lb]
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.