How to Remove a CVT On a Chainsaw

We will describe the process gradually step by step.
First of all, you need to remove the plastic, which prevents us from getting to the engine.

The next step, unscrew and remove the carburetor (In this case, it is not necessary to disconnect all the hoses from the carburetor, but just take it aside).

We turn off the muffler at the place of its attachment to the cylinder head and at the attachment point with the crankcase (2 long bolts). Now remove the muffler.

The next step is to unscrew the plastic cylinder head cover. (2 halves connected by two screws) After that, remove the cylinder head cover by unscrewing 4 bolts. Unscrew the chain tension regulator, which is located near the carburetor.

Next, you need to unscrew the 4 nuts securing the cylinder head, after which we can remove the cylinder head. When we removed the chain tension regulator, we released the chain and can easily remove it (after we removed the chain from the camshaft, it is necessary to fix it, for example with a wire, so that it does not fall into the crankcase)

In this photo, the head has not yet been removed, only the camshaft has been taken and the chain is locked. The next step is to remove the cylinder from the studs. If problems arise with this, you can lightly tap the wooden part of the hammer on all sides of the cylinder.

We put the piston in the top dead center position (the highest position is the position of the piston, we are guided by the marks on the rotor of the generator.) It is necessary to ensure that the chain does not fly off the drive sprocket so as not to bother with its installation in the opposite position. Take a clean rag and cover the crankcase opening so that various debris does not enter it. Remove the retaining rings from the piston and thereby release the finger (here you can use pliers or small pliers.) We remove the finger with a small wooden block (we try not to create a load on the crankshaft connecting rod). This completes the process of removing the old CPG.

Видео: How to Remove a CVT On a Chainsaw


Installation is carried out in the reverse order, having previously lubricated the cylinder, piston and rings with a small amount of oil. We install on the piston first a thin ring in the lower groove, then an oil scraper and again a thin ring (a wavy ring. oil scraper will thus be between two thin rings in the lower groove). Next, we install 2 compression rings) which are thicker). The cuts of all rings should not be above each other. After installing the rings, put the piston on the crankshaft connecting rod, fix its position with a finger and circlips. Take the connecting sleeves from the old cylinder and insert into the new one.

We put a gasket under the cylinder on the studs. Carefully put the cylinder on the piston with rings so as not to damage the cylinder. Push the chain into the groove for the chain. Then install the tire chain cylinder head. Now we can put the chain on the camshaft sprocket (the position of the sprocket should be as follows: a large hole at the top, and two small ones on the sides, parallel to the edge of the cylinder head). We fix the position of the cylinder head with the gasket by screwing it. Then we put the plastic cylinder head cover, chain tensioner, carburetor and silencer. Installation is now complete!

If you have not changed the oil for a long time, you must change it before starting with a new piston. Before giving full load to the scooter engine, it is necessary to run-in, i.e. Drive 300-500 kilometers at a speed of no more than 40-45 km per hour.

Along with an increase in the power of the scooter with the installation of a tuning CPU, the load on the variator with gears of the gearbox also increases. Keep this in mind and if possible, replace the variator with gears of the gearbox with tuning ones (more reinforced.)

How to Remove a CVT On a Chainsaw

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