I have a 250 HI-BIRD with a seemingly bad engine. I have the motor out and would like to (cheaply) replace it with another engine. I have found a few sites with engines that the seller claims will bolt right up but I really don't want to pay upwards of 500 dollars.

I am buying a brand named ATV this week but would still like to fix this chinese atv so freinds can ride.

I would even consider putting a 150cc in it if it will fit right.

Does anyone know of an engine that would fit this ATV? New or used doesnt matter to me as long as it works.

I tore apart the old engine and sadly did not find a single thing wrong with it. Clutch plates all looked fine, gears looked excellent. The ATV was clunking really bad in 1st gear is what made me think the clutch plates or the gears themselves were going bad.