Broken bolt on lower

[john from md]

My "new" Bayliner with 85hp Force has a broken bolt on the lower. It is one of the long ones that are along the sides. Should I try to drill it out and retap to a larger size? I don't know how long it has been broken or whether it is stainless or not.

I'm inclined to leave it alone but I am an aircraft mechanic and not a boat mechanic. Anyone know any reason why I should drill it out?

Regards,

John from MD

 

[Frank Acampora]

Re: Broken bolt on lower

Well, John! first of all, it is stainless which makes it a royal pain in the butt to drill out. As an aircraft mechanic, you should know that stainless is tough and gummy and the drill tends to wander even with a center punched start. Second, it is awkward to drill upward with the kind of pressure needed.

It is 5/16 so if you can ACCURATELY drill it out, (Premium new drill bit--Cobalt or such, slow speed, "pecking") you can re-tap to 3/8. That is if it aesthetically offends you.

There are 7 bolts holding on the lower unit and you still have 6 so personally, I would leave it alone--at least for the time being. Additionally, the 125 uses the same lower unit so 6 really should do on the 85--for the present.

Broken bolts really bother me though--the designer/engineer would not have put one there if it were not needed--so I would (if I intended to keep the engine) drill and retap as a winter project.

Don't discount an easy-out and lots of our friend heat to extract it, or a Vise Grip if some of it is showing. There is nothing there to be melted or harmed and heat can be used. Soak it in plenty of PB or such for a couple of weeks then try heat. The main trick is to have PLENTY of patience.

 

[Barnacle_Bill]

Re: Broken bolt on lower

If there is enough of it left to get vise grips on it, heat it like Frank said, and then slowly work it back and forth. It will come out.

 

[john from md]

Re: Broken bolt on lower

Thanks for the replies gentlemen. I plan to leave it till the winter. I don't hot rod the boat so it won't get any undue stress. I don't water ski anymore and only use the boat for fishing.

Regards,

John