851943 Volvo.Penta Screw

COMMUNICATORSSERVICE/WORKSHOP MANAGERSSERVICEMENTRAINING DEPARTMENTSProblem:
We have received complaints about excessive black accele- ration smoke, as well as "misadjusted" FARC's on new machine engines. DISCUSSION:0T or 2T Engine SPEC Micro Fiche information is test cell in formation only, and is made available to have the basic engine specs for a specific Engine Serial # Range, especially if the engine name plate is lost. - The VALID engine settings for individual engines are stamped on the ENGINE NAME PLATE ! - FOR EXAMPLE: The 988F FL Static Fuel Setting is 3.20 mm, the FT Static Fuel Setting is 3.79 mm and the FARC setting, which is best referred to as a "presetting", is .02 mm. - These # are as per the 2T4669 Micro Fiche Specs and may be different to what you find on the engine name plate of your machine. - FURTHERMORE - Rated speed or Full Load RPM - also mentioned on the name plate - is adjusted with the High Idle screw. Engine Power increases by up to 3% after "bedding in", which takes a minimum of about 500 SMU'S. FARC ADJUSTMENT: - The FARC "preadjustment" makes sure that rack travel is not restricted and producing an "acceptable amount" of black acceleration smoke, which means a different thing to different customers in different countries. - HENCE - with the FARC set as described above, and as per the correct info, it is still absolutely possible to experience an UNACCEPTABLE amount of black acceleration smoke! - It is also true, that some engines left the factory with POORLY preset FARC'S. - Especially engines with Serial Nos below 48W37008 and 73W15451. Solution:
If black smoke complaints are received, check/adjust the FL and the FT as well as the FARC as discussed above. - With ALL machine systems at normal Operating temperatures, run a "Stall Test" as per the corresponding Service Manual. Write down all the engine RPM's as per those tests and check the acceleration smoke with & without load. - The load used in this case would be the VCTC/ICTC. - In ADDITION, note the acceleration time from min to max speed, using a stop watch. It goes without saying, if the machine "fails" the stall test, troubleshoot for the cause and correct before going any further. IF with the FARC at spec, the black acceleration smoke is unacceptable to the customer, turn the FARC in the correct direction 1/2 of a turn at the time and rerun the above men- tioned "Stall Test", until you reach the point, when the FARC will start to negatively affect engine power and acceleration time. - Hence - the ideal adjustment is: A MINIMUM OF BLACK SMOKE WITHOUT RESTRICTING PERFORMANCE and is engine individual. FARC's can go out of "ideal" adjustment with age. CATERPILLAR MINING BUSINESS UNIT COPYRIGHT 1994 CATERPILLAR ALL RIGHTS RESERVED