stripped cyl head bolt top right side on a 4hp 1973

[crosbyman]

dang… 🙁 I was putting back together a 4hp I picked up last oct …. most ignition parts came in a cardboard box along with the cyl head ….found the top right cyl head bolt stripped.

what is the best option here … retap and try some kind of thread insert to build back to 7/16 or just redrill and tap the PH with a bigger bolt size ?

thanks

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• This topic was modified 2 years, 4 months ago by crosbyman.

[frankr]

I’m a big believer in Heli-Coils. Couldn’t live without them here on the Gulf Of Mexico.

P.S. it’s 1/4″ bolts, not 7/16″, but you knew that

• This reply was modified 2 years, 4 months ago by frankr.

[crosbyman]

thank Frank .. yes it is 1/4 bolt with a 7/16 head sounds good to me i’ll try to locate the proper insert….taps are not a problem 🙂

Joining AOMCI has priviledges 🙂

[crosbyman]

been browsing.. lots of Helicoil types some look like springs with a cross-bar at the bottom 1/4 20 others are just inserts like the ones used to fix spark plug threads . 1/4 20

any type better than others … ??

thanks

Joining AOMCI has priviledges 🙂

[frankr]

I only have experience with “real” HeliCoils. They require special taps and insertion tool, which come in kit form. But once you buy the kit you are set forever, except for buying more inserts, of course.
See this video for a quick lesson. https://www.youtube.com/watch?v=9rtiFBC0wms

[crosbyman]

great video it explains the 90 degree cross section and how to break it of when inserted. I assumed it stayed in there…

NAPA visit tomorrow !

Thanks

Joining AOMCI has priviledges 🙂

[Monte NZ]

Frank suggested earlier this year that I get a Hekicoil kit to fix the stripped head bolts on the 1964 3hp that I’m restoring……..best advice I ever had!
You certainly won’t regret it!
Thanks Frank once again!

Monte NZ

[billw]

Heli-coil kits are like the outboards themselves. Eventually, you are going to want another size, and another, and another…..But that’s a GOOD thing. Done right, Heli-coils are stronger than the original thread.

Long live American manufacturing!

[crosbyman]

thanks all for mental support ….I did do a stripped spark plug hole years ago on a 7.5hp cyl head using the big tap , black inserts and punch kit but never so small as1/4 inch.

should be fine 🙂

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[joecb]

No don’t leave the stub, you should remove the broken off stub ,,, tweezers or a magnet will do it

Joe B

• This reply was modified 2 years, 4 months ago by joecb.

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