Leak Proofing Engine Sheet Metal
Within the vernacular of engines, the timing cover, oil pan, and valve covers are identified as sheet metal. In agriculture, the definition is expanded to include any light-grade metal enclosure that contains a liquid or lubricant. Often sheet metal parts are hard to seal. Most applications use a gasket between the cover and the main component.
A major frustration is a persistent leak even after the gasket has been changed. By employing the following measures, it will be fixed right the first time. If the leak site is tough to access, first try Permatex Spray Sealant Leak Repair. It is an excellent product. If you do end up changing the gasket, make sure you thoroughly clean the cover and part’s sealing surface.
Perform a visual inspection for imperfections along with high and low spots. Any difference that is greater than the gasket thickness will leak. The primary cause of warped sheet metal is over-tightening. The bolts just need to be snug to marry the cover with the gasket and only slightly depress it.
If RTV is used, keep in mind that it means room temperature vulcanizing. The sealer will not cure and form a gasket in a cold or hot environment. Do not add any liquid to the sheet metal enclosure until the sealer is cured. If possible, it is best to leave it overnight.
Just because the gasket fits does not mean it is made from the proper material for the task or liquid that needs to be contained. It is wise to use name brand or original equipment gaskets. There is a reason why they cost more.
By far, the most common cause of leaks is the deformation of the area around the bolt holes from over-tightening. Place a small ball peen hammer on the bowed bolt hole while resting the part on the edge of a workbench. Then hit the small hammer with a larger one.
The goal is to gently bow the sheet metal the other way so when it is tightened, it will then bend flush against the gasket or sealant. This is identified as peening the bolt holes back over.
Install the cover and all the fasteners, so they just touch the sheet metal. Then incrementally and in a crisscross fashion, make them all snug. Let the gasket rest for a few minutes and then go around the cover’s perimeter, snugging all the bolts evenly. If possible, repeat after a few thermal cycles
Curing Small Engine Starting Woes
The small gasoline engine is employed for a myriad of tasks on the farm. For the most part, they are dutiful soldiers – that is, if you can get them to run.
By far, the most common complaint is either hard starting or not running at all, a frustration we have all experienced. Due to the nature of their size, these engines are simplistic in design, a carburetor, and a pull-start. Most issues are related to the carburetor, a component that is tasked with atomizing the gasoline to ignite.
Three things need to happen to gasoline before it can run an engine. It must be atomized (broken into small particles), emulsified (mixed with air), and vaporized (phase change from a liquid to a rarefied form). The carburetor is responsible for the first two steps. At the same time, Mother Nature, through heat, does the last (latent heat of vaporization).
If the carburetor does a poor job of atomizing the fuel, all the other steps skew, and the engine is hard starting or will not run. A good indicator of this being a no-start and a wet spark plug. Once this happens, the electricity uses the fuel for a path to the ground instead of jumping the gap.
Since the engines vibrate, it is essential to keep all fasteners that hold the carburetor together and to the intake manifold or cylinder snug. Many designs use a rubber boot that connects the carburetor to the cylinder head, and over time it gets hard and cracks.
An early sign is difficult starting and an objection to idle. When an induction system has an air leak between the carburetor and the cylinder, the carburetor’s ability to deliver fuel is diminished.
The carburetor needs to be washed with a carburetor spray, and the air filter kept clean. Keep in mind a tired engine with worn piston rings and valves will not allow the carburetor to function and will be extremely hard starting with a pull-rope.
When faced with a problem, first check for spark and then pull the plug and examine it. If it is wet, there is fuel, but it is not being appropriately atomized. If it is dry, then either a circuit is dirty in the carburetor, or the ring seal is so poor in the cylinder that no signal is being created to pull fuel.
Many engines become hard starting and unusable due to a lack of oil changes when they were younger.