My friend has a 1980's 8.5 hp 2-stroke, 2-cylinder Evinrude outboard motor. After removing, cleaning and rebuilding the gunked-up carburetor, we found that the hole for the bolt that holds the throttle linkage to the motor was stripped out. We managed to get maybe a 1/2 turn engagement of threads at the bottom of the hole and the motor has run pretty well for several trips. Yesterday it came loose on the lake and we barely managed to get the boat back on the trailer. Short of buying a new head/crankcase for the motor, is there any way to fix this problem?

The bolt that holds the linkage is not an everyday, garden-variety bolt. It has a shoulder on it that allows the throttle linkage to pivot, so we probably can't just drill out and tap the hole for a larger bolt. We already tried a helicoil, but the proper-sized helicoil for the bolt (test-fitted on the bolt at the hardware store) would not fit in the hole, and we're hesitant to drill it out to fit. We've thought of JB Weld-type epoxy, but we're concerned that once it sets up, we'll never get the bolt out again. We assume the motor is aluminum, so maybe it could be welded, drilled and tapped??

Any ideas would be appreciated.