Next you will change the oil. To lower oil viscosity and get it moving freely run the engine for a few minutes. Now shut the engine off and roll the mower onto a piece of cardboard or drop cloth. Close the fuel line (if your mower has one) and unhook the spark plug as before. Find the oil filler tube and remove its cap. Often the cap also functions as a dipstick.
With the mower still on its side grab your socket wrench and wood block. Place the block inside the blade well. This is to prevent the blades from turning while you loosen their bolts. Remove the blade mounting bolt/bolts. A typical mower will have one blade like the Craftsman 37700 I serviced for this guide (one mounting bolt). Some like my Honda HRR216VKA have two blades an upper and a lower (two mounting bolts). Each blade should have at least two cutting edges.
EGO has two 21-inch deck 56-volt lithium-ion cordless battery mowers that are quite popular and share a number of similarities: the LM2101 and the LM2102SP. The major differences between the two are that the LM2102SP is self-propelled has a larger-capacity 7.5Ah battery and it costs $100 more. For the purposes of this review we are going to focus on the features they share in common.