'99 SV650 Curvy Cylinder head Exhaust studs

[turbominimagic]

Hi

Could someone please let me know the depth and size of the thread that the exhaust manifolds clamps too (via studs) on the cylinder head please?

I've managed to snap a stud off so need to drill it out and re-tap it. The other stud/nut is rusted solid too, so will probably have to do both!
http://lh6.ggpht.com/_WNSOT9QLbak/S4p3oPGb36I/AAAAAAAAEaU/qhSwrn-0fbE/s144/27032009106%20%28WinCE%29.jpg

Cheers, G

[yorkie_chris]

M8.

[turbominimagic]

Thanks for your quick reply. Any idea how deep the threads are? I don't want to drill into my cylinder/piston!

[yorkie_chris]

Not offhand, can have a look at a spare head for you if noone else knows.

Get a left handed drillbit. Chance it will unscrew itself then :)

Other one do not even attempt to loosen nut, grind through the side of the nut and tap it round with a punch.

[LiamH]

Just measured the scabby one that came off mine, they are 42mm long M8 and 1.25 pitch. I got some 40mm ones to replace them.

[zadar]

Any idea how deep the threads are?
15mm

[maviczap]

Put them back with some copaslip

[Spanner Man]

Good morning all.


Before you attempt to drill out the remaining intact stud, try grinding off the seized nut. Often the heat from the grinding will loosen it, & you will be able to turn it with a suitable pair of grips. Then run a die nut up the threads to restore them.
If there's any of the broken stud protruding, get a nut welded to it. The heat will help to loosen the stud, & you'll have something to turn. Use lots of penetrating oil as it cools down.
If you have to drill it out, I wouldn't drill more than 15mm into the head on the broken stud just in case. However as exhaust studs don't usually bottom out in their holes, if you get the drill central, you should break through the stud before damaging the cylinder head. Start with a 3mm drill & work you way up.


Cheers.

[punyXpress]

When you've fixed the studs, use BRASS nuts ( with a bit of Copperslip )

[fastdruid]

I use A4 stainless Aerolock.

Druid

[yorkie_chris]

I've not had a problem with stainless studs and nuts. About 9 months and 12000 miles and they came out fine. Dunno how long they should be realistically expected to last.