Broken starter bolt on 3liter 1988 bayliner Capri

[Stelder]

Was out on river yesterday boat worked great,but the last 3 starts sounded different (whining sound)got back to marina and parked it.
Went back today and took a look I found a bolt 7/16 by about 2" I think,under the motor,I believe it broke off from the starter (right side)
Boat still fires up no problem but sounds a little funny?whats the easiest cheapest way to fix this.?
It's a 1988 bayliner Capri bow rider with a 3 liter gm engine ,I was thinking of trying a little bit longer bolt to see if it grabs any threads, will try this when I have time.
It's not the easiest place to get at.

 

[John Vinzant]

If the bolt is intact, get a small mirror and check the bolt location that is to the outside of the starter, the bolt that's more toward the center of the engine is about 4 inches long with the threads. If the bolt you found is broke off, your going to need to have it removed. Drill and e-z out.
Hopefully you won't have to pull the engine.

 

[Scott Danforth]

You are going to have to at least pull the starter to get access to properly insspect and repair a broken starter bolt. most likely you will need to pull the motor

 

[Stelder]

I was able to get broken piece of bolt out without too much trouble ,I just loosened the other bolt on starter and pulled shims out,then took a scratchall
(Pointy screwdriver)and kept making counter clockwise circles with pick up against broken bolt and shazam it came out.I put a regular 7/16" bolt back in
Along with shims and tightened it all up,works great.Im going to get proper graded bolt and swap out the regular one I borrowed from work
Thanks for everyone's input.
Stay tuned for my next dilemma ,will post another ? On the whining noise when starting grrrrrrrrr.