105411-1401 ZEXEL 9 420 612 532 BOSCH GOVERNOR 9420612532 1054111401 1157209991

Caterpillar: Confidential Yellow
SUPPORT INSTALL NEW 7W1035 FUEL INJECTOR ASSEMBLY FOR SMOKE REDUCTION AT LOWER RPM - 3500 SERIES MARINE AND GENERATOR SET ENG INES WITH 1301 TO 1600 FULL LOAD RPM - PS0254 - MAILED TO US, AMERICAS, AUSTRALIA AND CANADA ONLY
  The information supplied in this service letter may not be valid after the termination date of this program.   Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
INSTALL NEW 7W1035 FUEL INJECTOR ASSEMBLY FOR SMOKE REDUCTION AT LOWER RPM, 3508 Series Marine And Generator Set Engines With 1301 To 1600 Full Load RPM, 1290, PS0254 U-50 A-26 AU-38 C-39 See May 30, 1986 support after failure only
Problem
Some users of engines with 2W5201 Injector Assemblies have complained of excessive black smoke when operated at lower rpm and load than the full load rating. The new 7W1035 Injector Assemblies will reduce the black smoke at the lower rpm and load.
Affected Product
Engines that have the following serial numbers and a full load rating from 1301 to 1600 rpm and where the users have complained of objectionable smoke are included in this program. Engine Model Serial Numbers 3508 Marine 96Y1-96Y651 3508 Generator Set (50 Hz) 23Z1-23Z810 3512 Marine 50Y1-50Y613 3512 Generator Set (50Hz) 24Z1-24Z1125 3516 Marine 29Z1-29Z790 3516 Generator Set (50 Hz) 25Z1-25Z572
Parts Needed
Model and Quantity Part No. Description 3508 3512 3516 7W1035 Injector As. 8 12 16 6V1250 Seal 8 12 16 8J8725 Seal 16 24 32
Action Required
There are two phases of this Product Support Program: A) investigation of the black smoke complaint; B) removal of the former 2W5201 Injector Assemblies and installation of the new 7W1035 Injector Assemblies if the smoke complaint is valid. A. INVESTIGATION Before investigating a complaint of excessive black smoke, basic information about the engine and its application must be gathered from the customer. You need to know: 1) If a marine application, the engine has a full load rated speed between 1301 and 1600 rpm and the objectionable smoke occurs at a steady-state engine speed between 900 and 1300 rpm. (Make sure this is not an acceleration or lug condition smoke problem.) 2) If a generator set application, the engine is operated at 1500 rpm with a 50 Hz frequency, and the objectionable smoke occurs at partial loads (30 to 70% of rated load). Depending on the application, the above statements must be true before an engine qualifies for rework