Topic: 400f broken exhaust stud

[wilson11]

So I've broken a stud off(#1 cyl inside) and can not remove it. Drilled it out ,penetrating oil and heat along with the stud extractor and still nothing.Now I figure the head has to come off because the hole  is still in good shape and I don't want to ruin anything further like break the stud extractor off in there or something.Can any forum members in southern Ontario Toronto area recommend a good shop to do this job? My mechanical abilities,tools and shop would be a little stretched doing this so I think I should get a pro to do this Thanks.

[Tim.]

Gord Bush Performance in Etobicoke.  Do you need a valve job?  Might be worth doing at the same time.  I had my XS650 head done there as well as boring/honing on my cylinders.

I had my CB550F work done up at Concepts on Wheels in Markham.  Also a good shop, but I'd strongly recommend Gord Bush.

Whereabouts in the GTA are you?

[wilson11]

I'm in Toronto, Bloor and Keele . I don 't think I need a valve job as it runs good (13000 mi)but when we get the head off will know better and take it from there but I'll probably do as much as I can while it's apart to save from doing it again down the road aways.

[Terry in Australia]

If you can get at it with an electric drill I'd leave the head on mate, and just carefully drill the remains of the stud out. Use the "small, bigger, bigger again and biggest" drill bit technique, then go buy a helicoil set (8 x 1.25mm?) and a new stud, and Bob's yer uncle.

I did it on my Suzuki GS1000 a few years ago, and was riding it again the same day, it cost way less than a shop would have charged, and I got a helicoil set to add to my collection of tools. Have fun! Cheers, Terry.

[wilson11]

I've already drilled it out but it's not perfectly centered so I am already biting into the aluminum and I don't want to lose too much material. What is the max size you could put in the head, 10mm?I only want to remove the head as a last resort but it's not a total loss as I can replace the seal between the cyl head and cyl barrel that feeds oil to the rockers because it's leaking.

[mystic_1]

At worst you can drill until there's just a thin shell of the stud left, then pick out the remains with a dental pick.  Next, take your now-oblong, oversized hole and drill it out to accept a metric Helicoil.  I'd get the helicoil kit first, so you know how large you can drill without going over.

mystic_1

[mattcb350f]

I'd take it to a machine shop and have them look at it. If you brake off a bit in there or worse, an extractor it's all over. If you're already into the aluminum than you are off center and it's really hard to get back. Machinists have a knack for broken studs but they really hate when they've been mangled to death. I know because I've done it myself 

If you don't need to remove the head than take the bike to someone to get it out. It might cost a bit, but not likely more than a top end gasket set, seals, etc....

 Matt.