Yes it is a new engine. When I had it running, just above idle it was very rich. I let it run about 4 minutes then was going to throttle up. It quit, I could not get it started again. I flushed the carb out, made sure it was getting fuel, checked the glow plug, checked the igniter still nothing. Put the carb on from my 75 and it fired right up. Still running it very rich. I do have it mounted on a plane, but I also have a flight stand at my home like the ones at the field,. Don't know what to look for on the original carb. I can take a picture of the carb if you think that will help.