I have an older 2 spd horse, and read somewhere about the harbor freight greyhound engines, so I got one. It runs fine, but when I till deep it cuts off? Is this the low oil shut down? I can level it off and it starts up again, only to go 20' and die again. It works fine on a shallow 4" till. I know you add gear oil thru the handle screw, but do you just add enough to the second plug on the side of the trans? I think I put in too much, it seems to come out the top screw by the pulleys. Thanks