Key Points for Overhaul of the Tractors Ventilation System

Ventilation of tractor engine includes two processes of exhaust and intake, which means that to remove the exhaust gas in cylinder and fill in as much fresh air as possible are the key points to ensure the dynamic performance of engine. It also solves the contradiction between high and low performance and plays an important role in the composition of tractor gasoline engine mixture and the uniform distribution of gas flow in the cylinder of diesel engine.

 

First, the valve is not tightly closed

The main phenomena of loose valve closing are engine starting difficulty, tractor power decline, black smoke emission, etc. Without pressure reducing, there will be a leak sound when the tractor crankshaft is shaken by hands.

 

There are four reasons for this problem:

 

1. There are carbon deposits, ablations, spots and even peeling between the tractor valves and the valve seat. One of the solution is to hinge the valve seat, smooth the valve, and then grind both. In serious cases, valve and valve seat should be replaced. Massey Ferguson tractor parts can avoid these cases effectively.

 

2. Incorrect clearance between valve rod and valve guide. The gap is too large and the valve wobbles, causing poor sealing when closed. The clearance is too small, the valve is stuck in the catheter, so that the valve is not tightly closed or cannot be closed. If the clearance is too large, replace the valve guide. If the clearance is too small, the catheter can be reamed with a reamer.

 

3. The spring of the tractor valve is not elastic enough or broken, so that the valve is not tightly closed or cannot be closed. You can only replace it if something goes wrong.

 

4. If the valve clearance is too small, it should be adjusted. After loosening the adjusting nut, unscrew the adjusting screw and then lock the nut.

 

Second, a tapping sound on the valve

The main phenomenon of tractor valve tapping is that a clear "rattle" sound can be heard in the valve chamber. The sound varies with the speed of the engine. Or a metal tapping can be heard at the junction between the tractor cylinder head and the cylinder block, but it is not crisp.

 

Here are four possible causes of the problem:

1. If the valve clearance is too large, the rocker arm should hit the top of the valve rod, and the valve clearance should be checked and adjusted.

 

2. Valve clearance is too small or valve drop is not enough, resulting in valve impact piston top. It is necessary to adjust the valve clearance or repair the valve seat before adjusting the valve clearance.

 

3. The valve spring breaks, causing the valve to fall but not fall into the cylinder. Valve springs need to be replaced.

 

4. The valve seat ring falls off and it needs to be replaced. Put the cylinder head into the oil and heat to about 100℃, and then knock the valve seat ring into the seat hole. After fitting, ground flat the surface and then ground with the valve to the specified requirements.

 

Third, the valve falls off

Valve shedding is manifested as a sudden tractor engine stall with a loud crash.

 

The main reasons for this phenomenon may be the valve lever lock or spring falling off due to vibration, spring broken, valve rod broken and so on. The way to fix this problem is to stop the tractor and replace the parts.