The flywheel can not wobble with only one bolt loose. It has a large pilot diameter to the crank shaft and a anti-rotation/indexing pin and 5 bolts would hold it flat to the flange if they are tight. So if it wobbled, then more bolts are loose. If you find all the other 5 nice and tight then you should be OK. If the threads are messed up: BEWARE!! Do not damage the female threads on the end of the crank!! If all other bolts are tight (to torque specs) then be sure the new bolt goes in with no problem, don't force it. Chase the threads on that one hole on the end of the crank if you know how. These bolts have lock washers on them and don't come loose unless someone did not torque that one or used old lock washers. There is a fairly large torque requirement on those. Probably 60 FT LBS. You should have had big trouble with the starter gear engagement if it was wobbling. this really all depends on if you find the other bolts tight or not. If one unscrewed and fell out, it was NOT torqued. Whoever installed the flywheel last needs a time out. We don't have winter here so I don't get that part but now it should roll easily, so just roll it to where it's "out of the way", make sure it's winterized and get at it in the spring.
