TAPPET CLEARANCE IS ONE OF THE MOST IMPORTANT CLEARANCE IN A 4 STROKE ENGINE. IT SHOULD BE TAKEN EVERY MONTH AS CLEARANCE MAY CHANGE DUE TO CONTINUOUS RUNNING OF AUXILIARY ENGINE.
TO TAKE A CORRECT TAPPET, THE POSITION OF INLET AND OUTLET VALVES IS VERY IMPORTANT. THE VALVES SHOULD BE FULLY CLOSED I.E THE ENGINE SHOULD BE IN COMPRESSION WHILE TAKING THE TAPPET.
THERE ARE 3 WAYS TO CHECK THAT UNIT IS UNDER COMPRESSION :-
- THE FUEL CAM SHOULD BE AT ITS PEAK.
- THE PUSH RODS OF BOTH THE VALVES SHOULD BE FREE TO ROTATE.
- THE FLYWHEEL MARKING.
OUT OF ALL THREE THE FUEL CAM AT ITS PEAK IS THE BEST AND MOST RELIABLE. AND IT SHOULD BE NOTED THAT TAPPET TO BE TAKEN WHEN THE ENGINE IS COLD.
PROCEDURE TO SET THE TAPPET :-
- ROCKER ARM TO BE REMOVED FROM PLACE.
- THE BRIDGE/YOKE PLACED AT THE INLET AND OUTLET VALVES ARE REMOVED FROM PLACE AND THE SCREW PROVIDED ON THE BRIDGE/YOKE IS LOOSENED.
- THEN WE HAVE TO FIRST ADJUST THE CLEARANCE AT THE TWO ENDS OF EACH BRIDGE SO THAT IT IS SAME FOR BOTH THE VALVES FOR EACH BRIDGE/YOKE I.E BOTH INLET OR EXHAUST VALVES MUST OPEN SIMULTANEOUSLY AND EQUALLY.
- THIS CAN BE DONE BY THE HELP OF A DIAL GAUGE AND SLOWLY RIGHTNING THE SCREW ON THE BRIDGE/YOKE
- ONCE DONE, THEN ROCKER ARM IS PLACED BACK AND TIGHTENING SCREW IS LOOSENED AFTER LOOSENING THE TIGHTENING SCREW NUT.
- PLACE THE FILLER GAUGE OF REQUIRED THICKNESS ON BETWEEN THE BRIDGE AND THE ROCKER ARM.
- SLOWLY TIGHTEN THE TIGHTENING SCREW OF ROCKER ARM.
- FEEL THE TIGHTNESS OF THE FEELER GAUGE. IF OK THEN LOCK THE LOCKING NUT AND THEN REPEAT FOR THE OTHER VALVE.
- ONCE DONE FOR ALL UNITS, ROTATE THE FLYWHEEL TO CHECK PROPER OPERATION.
2 responses to “HOW TO TAKE A TAPPET CLEARANCE”
Please use a techincal language to understand properly.
It need a picture so that a person who never saw a rocker arm arrangement. But if u have seen it then u can easily visualize what I want to say.