3HP folder - Stripped Head Bolts

1968 3HP Evinrude Folder, 3832A, and in the process of fixing up I replaced the head gasket today.

While slowly following the head bolt torque sequence in the workshop manual, with just a touch of anti seize on the bolts, two of the head gasket bolts would not torque anywhere near the recommended 40+ inch pounds and slipped, and I've stripped the threads in the head in two holes. Looks like the two bolts still are in ok, but not great condition.

Am I better off installing a helicoil, or tapping in new threads one size larger and go with a larger bolt? What would you all recommend? I'm thinking of replacing all the bolts too--

Any insight on the thread sizes on these bolts would also be helpful.

Thanks-

Probably go with a helicoil kit and new bolts. Don't feel bad, the holes were probably shot upon disassembly. These little gems can be troublesome to safely dismantle.

They should not strip at 40 INCH LBS torque

Although perhaps sounding self contradictory, I'm in agreement with both of the above parties.

If the bolt holes are indeed stripped, I would assume that someone in the past over-torqued the bolts... in which case, heli-coils would be the way to go...... BUT.................

Normally the book gives you a choice as in..... xx inch lbs to xx inch lbs, whatever the value is.... and if the bolt holds at the lower reading, if it were me, I'd let it be. However, that's your judgement call.

The proper torque on those is 60 to 80 INCH LBS-----Something is wrong if they are damaged at 40 inch lbs.-------Hopefully it was not confusion between FT-LBS and INCH LBS.

So, the two bolts loosened up at maybe 30 inch lbs - well below the 40-60 torque spec. They just spin without grabbing, and i was reluctant to torque the other bolts - so tomorrow we'll go buy some helicoils. maybe a few spares.

Are the bolts original / correct length ?

They appear to be. Had a little paint on them that matched the engine.

I have found that in some cases, when you go to remove the bolts, they drag and ultimately damage the threads. There are measures you can perform to minimize this, but it takes time and patience.