Yeah it runs great at Coral Pink Sand dunes with a 220 main in it, but thats something like 4500 feet or something. So when I take it to Dumont which is like 600 feet there are no more jets to richen it up. I've drilled some jets out and can't get the plugs to get black, which tells me when I go to 600 feet its going to be running lean. Do you think there could be something wrong with the engine, like low compression and the oil and fuel is blowing by the rings. I have not had a chance to do a compression check or leak down test yet. Any ideas what the comprssion should be?