Quad Racer swing arm bolt

[Dennis B]

I have a Suzuki Quad Racer that I need to pull the motor and rebuild. It's ready to come out but the swing arm bolt that goes through the outer swing arm bearings and the back of the motor will not come out. I have soaked it with WD-40 for days. I have hammered and beat on it and cannot drive it out. It's in so tight that taking a breaker bar and socket to try and move the bolt will swing the engine up and down. It's free through the frame but locked onto the engine. I thought about heating the engine with a torch to expand it enough to drive the bolt out but I fear warping the area around the hole were the engine splits. Any ideas how to get this bolt out without damaging anything. The threads are still ok because I left the nut on keeping it flush with the end of the bolt and using a nice square piece of round stock the size of the nut. Any help will be appreciated.