Attention! The intake and exhaust valve stems have the same diameters, but different poppet diameters, do not confuse them.
Checking the degree of wear of the valve guide bushing must be carried out in the following order. Prepare fixture «00.4.210» and a pointer indicator on the stand.
Remove the cylinder head and remove the valve. Remove carbon deposits from the inner surface of the guide bush.
Insert the new valve so that the end of the valve stem matches the end of the valve guide.
Install dial indicator (see fig. 3.7) and measure the clearance between the valve guide bush and the valve stem by the value of the maximum deviation of the valve head, which should not exceed 0.5 mm.
If an increased gap is detected, treat the guide bush with a reamer with a fungus (1, fig. 3.70) depending on the diameter of the valve stem from the tool kit «00.4.210».
Press the guide fungus (1) to the valve seat and ream the valve guide in a dry state, starting from the combustion chamber side. Turn the reamer once with a downward feed. After processing with a reamer, it is necessary to grind the valve seat and install the valve with an oversize stem (pic. 3.71).