'99 SV650 Curvy Cylinder head Exhaust studs - SV650.org

28-02-10, 02:11 PM

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!

Cheers, G

yorkie_chris · 28-02-10, 02:12 PM

M8.

28-02-10, 02:54 PM

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

yorkie_chris · 28-02-10, 02:55 PM

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.

28-02-10, 03:15 PM

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.

28-02-10, 09:09 PM

Quote:

Originally Posted by turbominimagic

Any idea how deep the threads are?

15mm

maviczap · 28-02-10, 09:15 PM

Put them back with some copaslip

Spanner Man · 01-03-10, 11:10 AM

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 · 01-03-10, 11:14 AM

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

fastdruid · 01-03-10, 11:18 AM

I use A4 stainless Aerolock.

Druid

28-02-10, 02:11 PM	#1
turbominimagic Guest Posts: n/a	'99 SV650 Curvy Cylinder head Exhaust studs 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! Cheers, G

28-02-10, 02:12 PM	#2
yorkie_chris Noisy Git Mega Poster Join Date: Apr 2007 Location: Halifax/Leeds Posts: 26,645	Re: '99 SV650 Curvy Cylinder head Exhaust studs M8. __________________ Currently Ex Biker Now rebuilding a 63' fishing trawler as a dive boat

28-02-10, 02:54 PM	#3
turbominimagic Guest Posts: n/a	Re: '99 SV650 Curvy Cylinder head Exhaust studs Thanks for your quick reply. Any idea how deep the threads are? I don't want to drill into my cylinder/piston!

28-02-10, 02:55 PM	#4
yorkie_chris Noisy Git Mega Poster Join Date: Apr 2007 Location: Halifax/Leeds Posts: 26,645	Re: '99 SV650 Curvy Cylinder head Exhaust studs 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. __________________ Currently Ex Biker Now rebuilding a 63' fishing trawler as a dive boat

28-02-10, 03:15 PM	#5
LiamH Guest Posts: n/a	Re: '99 SV650 Curvy Cylinder head Exhaust studs 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.

28-02-10, 09:15 PM	#7
maviczap Member Mega Poster Join Date: Mar 2007 Posts: 9,097	Re: '99 SV650 Curvy Cylinder head Exhaust studs Put them back with some copaslip __________________ We're riding out tonight to case the promised land Make everyday count RIP Reeder - Jolly Green Giant and comedy genius

01-03-10, 11:10 AM	#8
Spanner Man Member Mega Poster Join Date: May 2005 Location: Sunbury Middlesex Posts: 1,396	Re: '99 SV650 Curvy Cylinder head Exhaust studs 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. __________________ Spanner Man http://stewarts-motorcycles.co.uk/default.html

01-03-10, 11:14 AM	#9
punyXpress Member Mega Poster Join Date: Feb 2008 Location: Riding, North Posts: 2,664	Re: '99 SV650 Curvy Cylinder head Exhaust studs When you've fixed the studs, use BRASS nuts ( with a bit of Copperslip ) __________________ Was: K2 naked in rapid yellow - gone to a better? place Now: Street Triple R

01-03-10, 11:18 AM	#10
fastdruid Member Mega Poster Join Date: Jul 2003 Location: W Mids Posts: 2,037	Re: '99 SV650 Curvy Cylinder head Exhaust studs I use A4 stainless Aerolock. Druid __________________ '00 SV700S - '94 RVF400R - '97 RVF400R - '88 VFR750F

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