Rocker Cover - Broken Stud

[5twins]

You need a bottoming tap. That's a tap that doesn't taper on the end very much. It will tap threads deeper into a blind hole before it hits bottom. And yes, there are special Helicoil bottoming taps. I found some on eBay and did this very repair.

 

[YamadudeXS650C]

My local autoparts store carries "kits" which include a few coils plus the proper bottoming tap for a good price, and they tell you which size drill bit to use.

 

[650Burger]

`Great. That's where I messed up, I got a kit with a non bottoming tap. Thanks for your input, the helicoil saga continues.

 

[member28833]

Or you can just grind the tip off of your tap in hand. Grind it flat as high up on the cutting edge "lead in taper" as you desire. You should leave just a small amount of lead taper. You can cut threads nearly all the way to the flat bottom of the blind hole if you are careful

 

[5twins]

I used the normal tap with more taper to start the hole (it's easier), then switched to the bottoming tap.

 

[jetmechmarty]

http://www.xs650.com/threads/stripped-thread-repair-valve-cover-studs.56897/#post-636634

This is what I did. It works.

If you can do a Helicoil, that is the best repair.

 

[Steve C]

Here's the holes I had to fix from the (very ham fisted) PO. Timesert worked well. One hole was off center because he drilled into a broken piece of screw and the drill walked and wallered out the hole off center. Ended up taking it to a machine shop, they opened up the casting hole and rewelded it then I used the filter plate as a guide to drill a brand new hole and Timeserted it for good measure. I was lucky it was one of the holes that could be gotten at!!!
I like that the insert sits a little below the surface. Remains to be seen it it's gonna leak...Knock wood!