ESC wonderings

[SweSwagger]

I just bought my 1:8 electric buggy with a Xcelorin 160A ESC and a Leopard 2100kv motor. When i drove with it on my backyard track today the esc got really hot and stoped working for like 3-4 seconds to get a little bit cooler and then i could drive 4-5 seconds and then over and over again. So obveously the esc did overheat..but my question is why? I didnt drive so tough with it..Could it be the gearing that makes it hot? And in that case - you got any recomendations on what gearing i shall have to not get my esc so hot? (the track is mud/soil or what its called ^^)