You guys can forget about Yamabond. We tried it years ago and had ton of leaking crankcases. I think DA found this out also and they now use a gasket. Yamabond will disolve in gas and when we used it for a crankcase sealant it washed right out. The absolute best sealer for our two cycle engines is Loktite 5900 or the same thing found in some automotive parts stores is Permatex brand called The Right Stuff. A second best is permatex ultra black silicon. As for your bearing press fit it is always best to heat the crankcase and drop in the bearing. We use a propane torch to heat the case. As a manufacture we do not have time to heat every case so we use an arbor press to push the bearings in. The key is to make sure they are started straight and use a driver to fit the outer race only. Most every engine uses a .0005"-.0008" press fit on bearings. Any looser the aluminum case will expand enough during normal temperatures to turn loose of the bearing which is real bad and any tighter will make the bearing feal tight and prematurely fail. We use loctite 609 on all of our crankshaft bearings along with a press fit. If you do not have a press fit and only use loctite it will turn loose when the case expands with heat. The loctite sticks real good to the steel bearing but not so good to aluminum.