The engine starts to warm up, "does not pull". The reason for this can be the wear of the piston system, the malfunction of the ignition system or the gas distribution mechanism. Namely - the loss of tightness of one or more valves.
Instructions
Step 1
First of all, you need to make sure that it is the gas distribution mechanism that is to blame for this trouble. To do this, remove the valves from the cylinder head. Before removing, mark them, because after inspection and repair, each of them must return to their place.
Step 2
Thoroughly clean the valve seat and around the valve head and the valve seating surface. Examine the cleaned surfaces carefully. If you find at least one of the following malfunctions, recovery is impossible, and these parts will have to be replaced:
• cracks, gouges in the saddle;
• defects on the working surface of the valve, burnouts;
• wear of parts in excess of permissible standards.
Step 3
After the defective parts have been replaced, lapping the valves and seats, followed by a check of their tightness (with the valve closed, no exhaust gases should pass through).
The lapping procedure is as follows: install a soft spring under the valve so that there is a gap between the seat and the poppet. It should retrace easily when the valve disc is pushed in until it touches the seat.
Step 4
Apply a thin layer of polishing paste to the saddle and turn the valve left / right 180 degrees. In this case, at the end of the turn, the valve is lifted by the spring, and it must be returned with a "slap", pressing it against the seat. Thus, carry out the lapping of the working surfaces. At home, it is better to do this with a brace, on the extreme part of which a rubber suction cup is worn.
Step 5
Check the lapping process visually. After a matte rim with a width of more than 1.5 mm has formed on the working surface of the valve, grinding can be considered complete.
Reinstall the valve. Check the quality of the work performed using the old proven method: pour kerosene under the valve and for 5 minutes see if it passes through the valve.
If there is no leak, then the work was done efficiently and additional efforts are not required from you. If kerosene leaks, then the operation with lapping the valve must be repeated.
