Broken head bolt. Evinrude 150 E150EXERV.

[woodycooper]

mercury casts an alloy in all there aluminum blocks so this problem never happens as aluminum corrodes and seizes any bolt so you were lucky to have only one broken - the best way for a pro repair, grind the top of the stud (broken bolt) so its pretty flat, center punch the center , using a small center drill drill the center not all the way , using smaller drill bits drill through the stud and no further you will feel it when it drills through the stud , next get the tap drill and drill through the stud, using a countersink or larger drill bit just use it to chamfer the radius of the new hole, basically just cleaning up the top of the hole then use a 3 flute taper tap same as your head bolts use some cool tool or cutting oil to aid in tapping and just a bit at a time in and out clearing away any chips ,i say use a 3 flute as the 4 flute taps bind up and may break , i cant stress enough take your time and if you dont have a drill press drill straight not crooked, dont weld anything to the existing stud as you may get into a bigger mess, when the tap starts to tighten up back it out air blow the hole to clean out metal chips and proceed until your through and done! a pro job!!

That's pretty much what the welders did. They drilled the bolt until only a thin layer remained then removed it with the tap. Anyway they got it out and I was able to purchase a new head bolt and get it done. It cost me $50 so I cannot complain at all.

 

[woodycooper]

just to introduce my self a fella from canada
Have been a marine technician for the last 35 years and millwright machinest semi retired as i call it as now i get all kinds of my past customers coming to my house and shop , i did not advertise it but word of mouth travels fast lol
and from my place i charge around 70 hr as the shop i retired from charged 129 hr good supplement for my pension i guess and hopefully help some folks out here thank you

These guys charged me $50. They do about anything. It took them a while since they did it between "real" jobs.

 

[woodycooper]

??----Have you used a drill press on a block that was still mounted on the boat ?----Just curious here.-----You mentioned ---" if you don't have a drill press drill straight not crooked " ----I believe.

I think you might be referring to one of the commenters but I'll chime in here: I didn't drill anything, but the shop did, by hand. Their repair was successful in the end and cost me next to nothing.

 

[tphoyt]

$50 bucks is a steal. Shops in my neck of the charge that just to pick up phone. Average cost would be in the neighborhood of $140 an hour.

 

[ONERCBOATER!]

50 bucks...is awesome.
For cast iron engine blocks a Mag Drill will often work for drilling via drill press without removing engine. For aluminum outboards I have always used good and sharp left handed cobalt drill bits and patience....lots of patience...and a bit more patience. Often as you drill the screw or bolt the heat and pressure of cutting with left handed drill bit will spin it out...and most often as you go up a size and relieve stresses in bolt by removing more and more of it it just spins out...sometimes just threads come out as everything else drilled away.

If you not comfortable then by all means have a professional do it.

Sean

 

[woodycooper]

50 bucks...is awesome.
For cast iron engine blocks a Mag Drill will often work for drilling via drill press without removing engine. For aluminum outboards I have always used good and sharp left handed cobalt drill bits and patience....lots of patience...and a bit more patience. Often as you drill the screw or bolt the heat and pressure of cutting with left handed drill bit will spin it out...and most often as you go up a size and relieve stresses in bolt by removing more and more of it it just spins out...sometimes just threads come out as everything else drilled away.

If you not comfortable then by all means have a professional do it.

Sean

That's about how he did it, in so many words. He drilled until there was only a tiny ring of thread left and the used a tap to clear that out and blow out the pieces. He was a professional welder but around here everyone has a boat and so your likelihood of finding someone who knows what they're doing is increased. I've learned a broken head bolt is something that requires the right tools and experience so yes, I wouldn't recommend it for the casual mechanic. I've done lower units, timing and linkage adjustments, carb rebuilds, fuel pump rebuilds /replacements, and tested many other components, and I will still pay someone whatever it takes to do this if it ever happens again.