I'd take one of the covers off the carb to make sure the diaphrams are soft and supple, not stiff. If they're stiff, you can get a carb kit from the local saw/mower shop. I've never tried the wd 40 . I'd go through the procedure I pointed out above and let er rip. Do they give an indication of the prop size? I have no idea because of the reduction drive. Just be carefull as there's a lot of potential power there Jeff. Are you going to run it on a test stand?