Hello all! I got a no name ATV from my brother in law as a gift when the missus and I bought a small horse farm, about 8 acres. It's 107cc and says "Loncin" on the engine. We maily use it to pull a tow-behind mower, and drag pastures (dragging a section of chain link across the pastures to break up old horse poop). Yes, I know 107cc is not nearly enough for towing anything, but we're a bit strapped for cash and work still needs to get done.
Anyhow, horses are her thing, so during the winter I never use it. Friday she complains that it's been running ratty for a while, so I check it out and find out it's got ZERO oil in it. The seals around the block look like caramel and the dipstick got so hot it shattered in the block. Apparently it's been like that a while and been used for heavy duty work. I flushed the system with a few consecutive oil changes, got some crud and sludge out and incredibly it seems to be running ok. It leaks oil from the shifter, but no big deal.
Anyhow, here's the problem... It has significantly less power than it did last year. It's revving fine (if anything, too high), but at half throttle it has no more pick up. Did the lack of oil damage it permanently? Has the towing heavy stuff burned out the clutch? What do you think?

 

You said the dipstick shattered in the block? Did you remove all the parts? I would split the case if nothing else to just check to make sure there are no parts in there