I have a 1995 Four Winns 170, 3.0L OMC Cobra. There has been a loud intermittent noise, at start-up, that sounds like a metallic chirpping or what a car's metal fan would sound like if it hits as it goes around. Goes away when driven. The shop looked at it and told me there are bolts that hold the starter in (starter replaced 2 years ago at other shop) and one of them sheared off (with the bolt stuck in the block) so the noise is due to the starter not being held in place properly. Told me it could ruin the starter, and drive ring? that connects to engine. Fix is to remove the engine, turn upside down, and drill out the bolt so the starter can be correctly attached (since they can't get to it). I asked if any other way to stabilize starter and they didn't think so. Does this sound like the right and only fix (at $700-$800 labor)? A friend referred me to this shop (first time here for me), so I believe it is reputable, but needed a reality check on this. Thanks much.