Posted by Gary Stewart (76.188.53.125) on June 07, 2007 at 23:43:15:
In Reply to: Failed valve seat posted by Larry Rarus on June 07, 2007 at 19:16:55:
Short of buying a short block, there are 2 methods of repair.
Put the seat back in and by using a flat punch, move about 1/8" away and "mush" the aluminum over the edge of the seat. Work all the way around the seat, actually moving the metal over the edge. Once secured, recut the seat and lap the valve.
Method 2-- remove engine and take to an auto machine shop. They can cut the hole bigger and install an oversize seat.
Now fix the problem---seat came out due to "overheat". Either the fins were plugged with dirt/grass or the oil wasn't good enough for air cooled application.