KLT 250 carb replacement

[BigHeadJeff]

Howdy all. I'm brand new...just joined so I could pick ya'll's brains on this problem. I'm no mechanic, but I do know that the air adjustment screw on the car for my '82 KLT 250 is broken off in the hole, and it keeps fouling the plug as soon as I replace it. So I'm trying to find a replacement carburetor but have had no luck so far. Aside from finding a carb from the same make, model and year, how can I tell if another carb will fit, e.g., after-market or similar model??

Thanks,
Jeff