i picked up a used 1985 Honda 125 trx and it starts right up. First problem was it idles really high. Next problem was that when I Ran it around yard, it bogged down and had no power. Revel up high but only slowly gained power and began moving again. I shut off. Engine was really hot. Checked oil and it was way up on dipstick. Can anyone give advice to where I should begin. I’m new at this. Thanks