Cummins/Onan B43 / B48 — Cylinder Honing
Repair & overhaul · cylinder block
For the Cummins/Onan B43 / B48, from the Cummins/Onan service manual.
Applies to: Cummins/Onan B48
Before you start
- Do not use a solvent or gasoline since they wash oil from the walls but leave the metal particles.
Procedure
- Position block solidly for vertical or horizontal honing; use drill press or heavy-duty drill at approximately 250 to 450 rpm.
- Follow hone manufacturer's instructions for use of oil or lubricant on stones; do not use lubricants with a dry hone.
- Insert hone in bore and adjust stones to fit snugly to the narrowest section.
- Start drill; move hone up and down in bore with short overlapping strokes about 40 times per minute.
- Check diameter of the cylinder regularly during honing at six places.
- Crosshatch formed by the stones should form an included angle of 23 degrees.
- Clean cylinder bores thoroughly with soap, water and clean rags.
- Dry crankcase and coat it with oil.
Tools required
- precision hone Amazon
- drill press or heavy-duty drill (250 to 450 rpm) Amazon
- dial bore gauge or telescoping gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Surface finish 20 to 40 RMS
- Hone speed 250 to 450 rpm approximately
- Crosshatch included angle 23 degrees
Full service-parts list: Cummins/Onan B48 →
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.