rt138DATA & SPECIFICATIONS RT-138 Issue 1, Page 11 13 Cylinder oils of excessively hh BN for the fuel sulphur can lead to excessive piston crown deposit accumulation. Piston crown deposits need to be carefully monitoredRt 138 Cafe, Mount Olive, Illinois. 1,058 likes · 1 talking about this · 1,121 were here. Breakfast, lunch, and dinner served all day! Open 6 days a week Tuesday - Saturday 6am to