so I was running my granite the other day and saw smoke coming from the engine, i cut it off let it sit. It ran alright for a little bit then cut about 75% of the power while on the ground. While holding it up, the wheels would spin slowly and build up to about 60% strength. I sprayed some wd40 in it and it ran a little bit better but seemed to lag going up hill. I just put in an HPI 15T engine and it seems to be running very quick but after climbing some hills it started to smoke as well... any ideas?