I just found and fixed the common Husky 51-55 intake manifold leak where the nuts were tightened too much stripped the screw holes in the plastic heat shield behind the carb. I drilled out the stripped holes to insert small machine bolts (1/4 inch SAE, I think) that fit the carb bolt holes from behind the shield. I had to grind down one side of the bolt heads to clear the intake manifold. Grinding down just one side prevents the bolt from turning when tightening down the carb. Then I installed the gasket, carb and inside air box piece(s) and nuts to know where to cut off the too long bolts. Then I took the assembly apart, cut the bolts and beveled the end threads to ease putting on the nuts. Solved the persistent vacuum leak. And now you can't tighten the carb bolts too much! My repair works on most all Husky saws with the plastic heat shield where the stock screws strip out the holes.
