0314137 JOHNSON BUSHING, Throttle cam

REMOVING EXHAUST VALVE SEAT INSERTFreeze the exhaust valve seat inserts or use the 8S7170 Valve Seat Insert Puller Group to install inserts into head. Be sure bores are clean, free of burrs, and the insert has a good press fit into the bore.After inserts are installed, grind the seat face of the insert to be sure it is flat, has the correct angle, and is in alignment with the bore in the valve guide. For specifications, see VALVE GRINDING SPECIFICATIONS CHART. Replace exhaust valve seat inserts when valve seat width or valve head-to-cylinder head face cannot be machined to the correct specification. For specifications, see VALVE GRINDING SPECIFICATIONS CHART.A 2N8943 Valve Seat Insert for the intake valve is available. This insert can be used in the repair of cylinder heads which have an intake valve seat with damage. Before, damage to an intake valve seat made replacement of the cylinder head assembly necessary.To use a 2N8943 Valve Seat Insert, the inlet port of the cylinder head must be machined to a diameter of 2.1470 .0005 in. (54.534 0.013 mm) and to a depth of .442 .002 in. (11.23 0.05 mm).To install a 2N8943 Valve Seat Insert into the cylinder head, freeze the insert or use a 2P2343 Extractor with the 8S7170 Valve Seat Insert Puller Group. After an insert is installed, grind the seat face of the insert to be sure it is flat, has the correct angle, and is in alignment with the bore in the valve guide. For specifications, see VALVE GRINDING SPECIFICATIONS CHART.Clean valve guides of all carbon and oil, using the 5P5176 Brush and a solvent.The valve guides are cast in the cylinder heads. Check each valve guide bore size 3/4 in. (19.1 mm) deep from each end. The bore size is .3745 .0005 in. (9.512 0.013 mm) and the maximum size worn is .3760 in. (9.550 mm). Valve guides worn more than the maximum wear size, can be restored to original tolerances through knurling.Use the 5P3536 Valve Guide Gauge Group to check the bore of the valve guides. Special Instructions GMG02562 gives complete and detailed instructions for use of the 5P3536 Valve Guide Gauge Group.
USING 5P3536 VALVE GUIDE GAUGE GROUP If valve guide bore is larger than .381 in. (9.68 mm), knurling may not restore the guide to original tolerances.The following procedure can be used to knurl valve guide bores using the 5P5170 Knurling Group:
5P5170 KNURLING GROUP
1. 5P5178 Lubricant. 2. 5P5187 Tap Wrench. 3. 5P5177 Speed Reducer (7 to 1). 4. 5P5176 Brush. 5. 5P5175 Knurling Arbor. 6. 5P5171 Reamer (.371 in.). 7. 5P5172 Reamer (.372 in.). 8. 5P5173 Reamer (.373 in.). 9. 5P5174 Reamer (.374 in.).1. Clean and buff head, guides and valves. Check valve stem diameter. The intake valve stem diameter is .3725 .0005 in. (9.462 0.013 mm) and the minimum size worn is .3710 in. (9.423 mm). The 9L8377 straight stem exhaust valve has a stem diameter of .3715 .0005 in. (9.436 0.013 mm) and the minimum size worn is .3700 in. (9.398 mm). The 9L9244 and 9L7683 tapered stem exhaust valves have a stem diameter of .3715 .0005 in. (9.436 0.013 mm) at the keeper end of the stem, and .3705 .0005 in. (9.411 0.013 mm) at the head end of the stem. The minimum size worn is .3690 in. (9.373 mm).2. Place head on the FT806 Cylinder Head Bench or 8S6691 Cylinder Head Stand with rocker arm side toward you. Use FT967 Adapter Plates to mount head on FT806 Cylinder Head Bench.3. Dip the 5P5176 Brush (4) into the 5P5178 Lubricant (1) and run the brush through the guide. The 5P5178 Lubricant is specially formulated for knurling cast iron guides and will prolong arbor life. If not available, use only Black Sulfur cutting oil or parafin base oil.4. Dip the 5P5175 Knurling Arbor (5) into the 5P5178 Lubricant just prior to knurling. Use the 5P5177 Speed Reducer (3) and a 1/4 inch electric drill (1200 to 1600 rpm recommended) to drive the arbor. Hold the speed reducer and drill firmly during knurling. Do not push or guide arbor during knurling.
KNURLING GUIDE
3. 5P5177 Speed Reducer. 5. 5P5175 Knurling Arbor.5. Select the reamer that is closest to the size of the valve stem that is to be used and ream the guide using the speed reducer and 1/4 inch electric drill. Push firmly to ream.
REAMING GUIDE It is not necessary to use lubricant for reaming.6. Clean the valve guides with brush and solvent. Dry the guides.7. Install the valve. It is permissible to use a maximum force of 6 lbs. (27 N) with no oil to install the valve. Should valve not fit, use next size larger reamer and ream as in Step 5.8. Thoroughly clean the valve guide bores after knurling.The following procedure may be used to knurl valve guide bores using the United Tool Process.1. Clean and buff head, guides, and valves. Check valve stem diameter. The intake valve stem diameter is .3725 .0005 in. (9.462 0.013 mm) and the minimum size worn is .3710 in. (9.423 mm). The 9L8377 straight stem exhaust valve has a stem diameter of .3715 .0005 in. (9.436 0.013 mm) and the minimum size worn is .3700 in. (9.398 mm). The 9L9244 and 9L7683 tapered stem exhaust valves have a stem diameter of .3715 .0005 in. (9.436 0.013 mm) at the keeper end of the stem, and .3705 .0005 in. (9.411 0.013 mm) at the head end of the stem. The minimum size worn is .3690 in. (9.373 mm).2. Place head on the FT806 Cylinder Head Bench or 8S6691 Cylinder Head Stand with spring end of valve guides toward you. Use FT967 Adapter Plates to mount head on FT806 Cylinder Head Bench.3. Select the drill jig that corresponds in size to the valve guide. Use the 3/16 in. drill and stop in a slow speed drill. Drill an offset hole in