The changes are very significant:
- it is a camshaft drive using a toothed elastic belt (pic. 7). Belt 5 is made of special rubber reinforced with a glass cord cord, and its toothed (122 teeth) the surface is covered with a special elastic fabric. Since the toothed belt, in addition to the camshaft, also drives the oil pump and the ignition distributor, its length is quite large. Therefore, the design provides for a new tensioner. It is convenient that the new drive does not need lubrication and is reliably protected from dust and dirt. In this regard, its performance is maintained for 60-70 thousand kilometers;
- these are new pistons. To exclude cases when, due to the fault of an inexperienced driver, the piston «is catching up» valve (this occurs on older engines when the crankshaft speed is increased above 6000 rpm), holes are now made in the bottoms of the pistons. Thus, the meeting of the piston with the valve disc is excluded even in cases of unforeseen circumstances;
- it's a new ignition system. The engines are equipped with a new R-125D ignition distributor, equipped with a vacuum automatic advance. As soon as the load on the engine decreases, the machine immediately increases the ignition timing and thereby maintains the most economical mode;
- this is an air filter equipment with a device that automatically maintains a constant temperature of the air entering the carburetor;
- this is a significantly improved carburetor, the merits of which we will dwell on below.
No matter how perfect the engine is, no matter how many automatic devices are mounted on it, its normal operation can only be ensured if it is regularly and competently maintained in good condition, that is, timely adjustment work.