Exhausting Studs

Post your Oilhead technical queries here

Moderator: Moderators

ptjenkins65
Club Member 14
Posts: 123
Joined: Thu Jun 08, 2017 7:49 pm
Country of Residence: United Kingdom
Location: London

Exhausting Studs

Postby ptjenkins65 » Fri Jan 17, 2020 7:47 am

Hi All. I couple of little question to the panel.
My 1999 r850r developed a slight oil leek from the left hand junction of cylinder to block.
Despite my best efforts to remove the nuts connecting the exhaust to the cylinder heads carefully ( lots of WD40 and heat ), three of the 6 studs have sheared off. It looks like it has never been apart before, the domes on the nuts had all but one rotted away.
My questions are:
What is the best way of extracting the remains of the studs?
If i have to, am I ok to remove both cylinders at the same time to get the studs removed. If so whats the best procedure.
Thanks very much.
Pete
1998 r850r
1979 r45
1974 r60/6
Still learning

King Herald
Forum User
Posts: 815
Joined: Wed Apr 05, 2017 3:24 pm
Country of Residence: United kingdom
Location: Midlands.

Re: Exhausting Studs

Postby King Herald » Fri Jan 17, 2020 9:29 am

You might get away with welding a nut over the broken stumps, and the heat shock, expansion etc, will loosen the sieze and corrosion up enough to be able to screw the stumps out. I think they are 8mm, and if they are broken off flush, drop an 8 mm was her over it, then put a 10 mm nut over, and fill with hot weld, with a Mig preferably. Let it cool very briefly, then try and unscrew it. Usually works, I’ve done it several times.

Or, you might have to carefully drill out and remove the broken bits. Which won’t be easy as they are sunk into the head somewhat. You can buy left hand drill bits, that can help unscrew the remains as you drill into it, but getting the hole centred and aligned to start with is the hardest part.
1997 BMW R1100R
1993 Honda Transalp 600

User avatar
Galactic Greyhound
Moderator/Club Member
Posts: 9653
Joined: Sat Aug 28, 2010 11:26 pm
Country of Residence: Scotland
Location: Dumfries

Re: Exhausting Studs

Postby Galactic Greyhound » Fri Jan 17, 2020 10:26 am

LEAK:
You might try CAREFULLY re-torquing the LH cylinder head to see if that clears the LH cylinder-block weepage.
If not, and the weepage is only slight, consider leaving it as it is but monitor it regularly for any increase in weepage.

STUDS:
WD40 is not very good at freeing off rusted threads - you need to use a proper anti-seize penetrant designed for this purpose - Halfords penetrants I have found to be quite good. Apply and leave overnight.

Try and fix the stud problem without removing the cylinder heads which will involve much more time and effort.

If drilling, be very careful not to drill longer than the stud in the head or you will break into the cooling oil chamber around the exhaust valve (that's why it's called an Oilhead!).

If this happens, it will be very difficult to seal the leak as the oil is under pressure.

Put a piece of tubing over the drill bit so that the drilling end of the bit is shorter than the length of stud in the head to prevent over-drilling.

As KH says, use a set of Left Hand drill bits (start small and increase as required) and pay particular attention to getting the drill bit correctly centered and in-line on the broken stud.

Once the broken stud is removed or the hole/threads drilled out, you might fit a Recoil/Helicoil type M8x1.25x2.5D insert (Length = 2.5 x Diameter) if the threads have been damaged/rusted out.

If you have the 3-stud fixing, you will likely get away with using only 2-studs which might save you some grief.

Grease the studs with copper anti-seize grease before inserting in the head and do not over-tighten.

You can get stainless steel M8x1.25 Dome nuts online from A2A4 Fixings Ltd. which protect the standard studs and look much better and last longer than the standard cap nuts.

In future, consider removing/renewing the exhaust studs every 2 or 3 years (by double-nutting) to avoid this happening again.

CYLINDER HEADS:
You can remove both cylinder heads at the same time.

First, remove both Spark Plugs and Cam Sprocket Covers on the Cylinder Heads.
Note down and mark the normal direction of rotation of the Cam Sprockets with a marker pen by rotating the rear wheel in-gear in the normal direction of rotation.
CAUTION: Never rotate the engine by more than a few degrees against its normal direction of rotation and always finish with normal rotation!

Next, place the LH cylinder in the 'OT' flywheel mark position on COMPRESSION stroke (both valves fully closed) and lock the flywheel in this position with a locking pin through the Flywheel Locking Hole by the Starter Motor into the flywheel (flag the pin with coloured tape so it gets seen and removed before start-up!)

Now check that the cam sprocket timing marks are shown to be in correct alignment on both cam sprockets. It is a good idea to use a fine-tipped marker pen to make the alignment easily read especially on the RH side which will be near the end of the EXHAUST stroke and not on the Compression stroke i.e. it will show as 180 deg off.

It may be desirable to loosen both the Cam Chain Tensioners at this stage to aid cam sprocket refitting but FIRST zip-tie the Cam Sprockets to the cam chains before removing the sprockets from the Cam Shafts to keep the cam timing chain/sprocket tooth position. Be careful when handling that the chains do not come off the lower auxiliary shaft camchain sprockets.

Next, remove the LH Cylinder Head then the RH Cylinder Head.

When refitting the heads, remember that the LH head will be on compression (both valves fully closed) but that the RH head will be near the end of the EXHAUST stroke (exhaust valve open) so that fitting the RH cam sprocket onto the RH cam may be a bit more fiddly due to the exhaust valve spring trying to rotate the camshaft hence the advice on loosening the Cam Chain Tensioners.
NOTE: When positioning the Cam Sprockets on the Camshafts, ensure that all slack is taken out of the Cam Chain by hand-rotating the sprocket in the normal direction of rotation (as previously marked!).
If this isn't done, then the cam timing might alter when the Cam Chain Tensioner takes up any slack in the chain if the sprocket has not previously been zip-tied to the chain i.e. the sprocket might be set one tooth off on the chain.

Next, ensure that both the cam sprocket timing marks are correctly aligned as checked before starting the dis-assembly after fitting the cam sprockets and cam chain tensioners and before removing the zip-ties.

Refit the spark plugs.

CAUTION: Remove the flywheel 'OT' locking pin by the Starter Motor before restarting!
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

ptjenkins65
Club Member 14
Posts: 123
Joined: Thu Jun 08, 2017 7:49 pm
Country of Residence: United Kingdom
Location: London

Re: Exhausting Studs

Postby ptjenkins65 » Fri Jan 17, 2020 2:58 pm

Thanks guys. Right now I am struggling to get the manifold off, like I said, never been off the bike I think. Got to get some proper penatrsting oil like you say
I will try re-torquing the the head first, clean it all up and see what happens. It had no effect that I have noticed on performance.
Sage like advice like normal from the forum
1998 r850r
1979 r45
1974 r60/6
Still learning

User avatar
Galactic Greyhound
Moderator/Club Member
Posts: 9653
Joined: Sat Aug 28, 2010 11:26 pm
Country of Residence: Scotland
Location: Dumfries

Re: Exhausting Studs

Postby Galactic Greyhound » Fri Jan 17, 2020 3:24 pm

Get a length of softwood (2" x 2") and a lump hammer.

Place the wood against the pipe and tap the header pipe near the top of the bend towards the front of the bike - go easy not to dent the pipe - it will eventually come free.

There is a sealing insert in the cylinder head exhaust manifold which will be carboned up and sticking the header pipe.
Penetrating oil won't work here as it is carbon and not rust that is causing the problem.
Carb Cleaner is a better option.

Normally no need to renew these sealing inserts, just clean up the manifold before refitting the header pipe and you could also use some copper grease as well.

If it is still stuck after that then consider first removing the exhaust system rearwards from the header pipe.

Be careful to first disconnect the cable connector for any exhaust Lambda sensor fitted.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

Jeff Highland
Forum User
Posts: 88
Joined: Sun Dec 25, 2016 7:05 pm
Country of Residence: Australia

Re: Exhausting Studs

Postby Jeff Highland » Fri Jan 17, 2020 10:12 pm

My RH cyinder to block has a weep, I considered pulling it to replace the gasket, but ended up just leaving it and washing the engine occasionally. It has never needed the oil topped up between changes.

andrewsf2
Forum User
Posts: 20
Joined: Tue Aug 01, 2017 2:57 pm
Country of Residence: Scotland

Re: Exhausting Studs

Postby andrewsf2 » Fri Jan 17, 2020 10:14 pm

Hi Pete,

I had sheared studs on both heads on my 1150RS despite trying penetrating oil and then welding nuts on.

I was fortunate there was enough stud sticking out to allow a nut to be screwed on - I used an M8 connector nut (only pennies from Toolstation or Screwfix). You then get a few M8 bolts and then drill a hole down the centre - say 3, 5 then 6mm. You can then screw the bolt into the connector but and use it as a drill jig. Watch the depth you drill!! You then go up the sizes as required. Just take your time and be careful!!
A helicoil/recoil kit is then all you need. I left one head on and did the other on the bench - both using a hand drill.

The replacement studs I bought (Motorworks I think) have a hex to take an Alien key.

Hope this helps.

Andrew.

User avatar
Galactic Greyhound
Moderator/Club Member
Posts: 9653
Joined: Sat Aug 28, 2010 11:26 pm
Country of Residence: Scotland
Location: Dumfries

Re: Exhausting Studs

Postby Galactic Greyhound » Fri Jan 17, 2020 11:43 pm

Hi Andrew,

I think that I rigged up something similar using stuck-on washers in order to jig up and ensure correct centring on the broken stud when drilling using a new LH drill-bit set. Sharp drills need to be used for accurate drilling.

From my records of the job at the time 5 years ago, I also used the following items:

1. M8 X 16 X 1.6 FORM A WASHERS A2 Stainless - For exhaust header pipes to cylinder head studs - Supplier A2A4 FIXINGS LTD.
A2A4 Fixings Website: http://a2a4.com/

2. M8x1.25 DOME NUTS A2 Stainless - Dome nuts 15mm high - For exhaust header pipes to cylinder head studs - Supplier A2A4 FIXINGS LTD.
A2A4 Fixings Website: http://a2a4.com/

3. STUD, EXHAUST M8x1.25 (QTY 6) - Motorworks Part No. EXA08133
Motorworks Website (studs EXA08133): https://www.motorworks.co.uk/vlive/Shop ... rch=SEARCH

4. RECOIL PRO XL THREAD REPAIR KIT, METRIC M8 - 1.25 x 2.5D - Part No. 35088 - Supplier RECOIL/ALCOA FASTENING SYSTEMS [Arconic]
Arconic, Recoil Thread Repair Kits, Website: https://www.hfsindustrial.com/pro-xl-th ... r-kit.html

5. 4-PIECE HSS DRILL SET, LEFTHAND CUTTING - Part No. 2726 - Supplier VERSANDHANDEL/AMAZON UK.
titanium coated
- sizes:
3 mm-4 mm-6 mm-7mm
- for drilling broken screws, bolts, etc.
In wooden case. £14.79.
4-Piece HSS Drill Set, LH Cutting, Sold by Versandhandel Erwin Lücken (Alle Preise inkl. Mwst.) and fulfilled by Amazon. Lefthand drill set for drilling out broken bolts.
Website: http://www.amazon.co.uk/dp/B001IL8GRO/r ... 51_M3_dp_1
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

ptjenkins65
Club Member 14
Posts: 123
Joined: Thu Jun 08, 2017 7:49 pm
Country of Residence: United Kingdom
Location: London

Re: Exhausting Studs

Postby ptjenkins65 » Mon Jan 20, 2020 9:33 am

Hi. I have just managed to get the manifold off. As you said Ced, i had to take the exhaust off backwards first. The shard studs are sticking out quite a lot, so a better penetrating oil and a mild heat of the cylinder around the stud and see what happens. Do you know around what temperature is safe to heat the head too?
Pete
1998 r850r
1979 r45
1974 r60/6
Still learning

User avatar
Galactic Greyhound
Moderator/Club Member
Posts: 9653
Joined: Sat Aug 28, 2010 11:26 pm
Country of Residence: Scotland
Location: Dumfries

Re: Exhausting Studs

Postby Galactic Greyhound » Mon Jan 20, 2020 11:03 am

Hi Pete,

If the shards are quite long you may be able to double-nut them so that they can be unscrewed after soaking in penetrating fluid overnight and with a bit of heat afterwards.

If they are not long enough for double-nutting, then consider filing a couple of shallow opposite flats and using a Mole-wrench to apply the turning moments.

Alternatively, KH's method of MiG welding nuts to the shards offers the solution to heating and turning the studs with less risk of a naked flame.

Re temperature, the exhaust headers can get cherry red at the manifolds if the bike is left idling too long but remember there is still cooling oil being circulated in the oil chambers around the exhaust valves in this condition.

You need to be very careful of the fire risk if using a gas torch and the plastic fuel tank is still mounted on the bike - you might consider removing it beforehand and waiting 24 hrs for any spills and fumes to disperse before using a naked flame on the bike.
The tank can also melt/distort if overheated.

Do not attempt to unscrew the studs in one go - they will shear off.
The strategy should be to apply an unscrewing force while watching the stud for the SLIGHTEST movement - at that point STOP!

Now RETIGHTEN the stud to where it started from and apply more releasing fluid and/or heat.

Repeat this procedure multiple times trying to gain a TINY bit more rotation each time without applying excessive force.

The stud might be heated up to a dull red colour BUT then left to cool a bit before applying any unscrewing force to it.
The alloy head around the stud thread will expand more than the steel stud which further helps in loosening.

The purpose of the heating/cooling is to expand/contract the stud so that the seized thread breaks free of the jamming corrosion by thermal movement and the TINY low-torque turning moments applied backwards and forwards clear the corrosion debris from the thread without the stud shearing.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

Mjolinor
Forum User
Posts: 2602
Joined: Tue Jun 12, 2018 9:38 pm
Country of Residence: United Kingdom
Location: Burnley

Re: Exhausting Studs

Postby Mjolinor » Mon Jan 20, 2020 12:08 pm

You can also gain a lot by quenching while hot to shock the stud/hole boundary.

Just a matter of sucking and see, do whatever works.

King Herald
Forum User
Posts: 815
Joined: Wed Apr 05, 2017 3:24 pm
Country of Residence: United kingdom
Location: Midlands.

Re: Exhausting Studs

Postby King Herald » Mon Jan 20, 2020 7:19 pm


Do not attempt to unscrew the studs in one go - they will shear off.
The strategy should be to apply an unscrewing force while watching the stud for the SLIGHTEST movement - at that point STOP!

Now RETIGHTEN the stud to where it started from and apply more releasing fluid and/or heat.

This something wise to do with every and nut, bolt or any other fastener. :cool:
1997 BMW R1100R
1993 Honda Transalp 600

ptjenkins65
Club Member 14
Posts: 123
Joined: Thu Jun 08, 2017 7:49 pm
Country of Residence: United Kingdom
Location: London

Re: Exhausting Studs

Postby ptjenkins65 » Tue Jan 21, 2020 8:47 am

Wow Ced, thanks for the tip to go to A2A4. Looking at the price difference on the items i just bought i saved myself nearly £40. I had to cut the retaining band off between the rear exhaust and manifold, that had sheard as well. Great advice.
I will not get a chance to revisit the troublesome bike until the weekend, but i will let you know how it all goes
1998 r850r
1979 r45
1974 r60/6
Still learning

User avatar
Galactic Greyhound
Moderator/Club Member
Posts: 9653
Joined: Sat Aug 28, 2010 11:26 pm
Country of Residence: Scotland
Location: Dumfries

Re: Exhausting Studs

Postby Galactic Greyhound » Sat Jan 25, 2020 5:03 pm

You might also try this to release the seized studs:

https://www.bmbikes.org.uk/viewtopic.ph ... e90899966a
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

ptjenkins65
Club Member 14
Posts: 123
Joined: Thu Jun 08, 2017 7:49 pm
Country of Residence: United Kingdom
Location: London

Re: Exhausting Studs

Postby ptjenkins65 » Wed Jan 29, 2020 6:40 pm

Hi Ced. I bought a product called liquid wrench. Its american and had good reviews. I have had a friend weld nuts on to the ends of the bolts and whilst still hot added more liquid wrench.
I am now wondering what temp I can heat the cylinder head to, around the bolts. I have a digital heat reader, so can be fairly accurate. Anybody got any ideas?
Pete
1998 r850r
1979 r45
1974 r60/6
Still learning

User avatar
bazzzer
Forum User
Posts: 141
Joined: Mon Jan 07, 2008 10:33 pm
Location: Newbury, Berks

Re: Exhausting Studs

Postby bazzzer » Fri Jan 31, 2020 9:40 pm

Heat - heat it until is is red and glowing (i.e. very hot)
New nuts. I replaced using stainless dome nuts, very cheap at Toolstation (91300 or 95284). They are also pretty good for stainless nuts around the rest of the bike
Bazzzer
Confirmed R1150RT fan \:D/ \:D/ (except removing the fairing and the fekin clutch !! :evil: :evil: )!

User avatar
Rob Frankhamr
Club Member 14
Posts: 4313
Joined: Mon Jul 25, 2005 6:33 pm
Country of Residence: Scotland
Location: Kinloch Rannoch, Perthshire

Re: Exhausting Studs

Postby Rob Frankhamr » Sat Feb 01, 2020 11:11 am

One thing that hasn't been mentioend... if you decide to drill the stud and/or use an 'eezi-out' (left hand threaded stud removing tap) be careful. Take it easy and don't break either drill or tap in the stud. If you do, a minor issue has just become a major problem. Removing the remains of a tool steel drill or tap from a mild steel stud in an alloy head is not something you want to be attempting!

Rob
Robin Frankham
ImageImageImage

Frankhams retirement home for elderly Boxers.

ptjenkins65
Club Member 14
Posts: 123
Joined: Thu Jun 08, 2017 7:49 pm
Country of Residence: United Kingdom
Location: London

Re: Exhausting Studs

Postby ptjenkins65 » Sun Feb 02, 2020 7:39 pm

Hi all. Well yesterday was S day, stud day to be exact. I talked to the very helpful Paul at Uni Thread. I bought a 4,6.5and 7.5 mm reverse thread drill bits and two M8 taps, one with a gentle lead in and one that started almost immediately. Two of the studs complied and were drilled and tapped nicely. The third didn’t like the procedure much. I can get a stud in, but I’m not sure how secure it is. I have some metal paste and will add that to the mix.
Returning to the original problem, I’m going to put everything back now I have properly cleaned it all and see if that really is the problem area. Once the bike was raised up, I suspect that the problem might be elsewhere.
You live and learn.
Now to try and fix the poor throttle response on my Honda CB450 K4.
1998 r850r
1979 r45
1974 r60/6
Still learning

King Herald
Forum User
Posts: 815
Joined: Wed Apr 05, 2017 3:24 pm
Country of Residence: United kingdom
Location: Midlands.

Re: Exhausting Studs

Postby King Herald » Sun Feb 02, 2020 7:52 pm

7.5 is far too big to use when drilling the studs out.Tapping size for 8 x 1.25 is just 6.8mm. That might explain why one is a bit loosey.
1997 BMW R1100R
1993 Honda Transalp 600

ptjenkins65
Club Member 14
Posts: 123
Joined: Thu Jun 08, 2017 7:49 pm
Country of Residence: United Kingdom
Location: London

Re: Exhausting Studs

Postby ptjenkins65 » Sun Feb 02, 2020 7:58 pm

Hi all. Well yesterday was S day, stud day to be exact. I talked to the very helpful Paul at Uni Thread. I bought a 4,6.5and 7.5 mm reverse thread drill bits and two M8 taps, one with a gentle lead in and one that started almost immediately. Two of the studs complied and were drilled and tapped nicely. The third didn’t like the procedure much. I can get a stud in, but I’m not sure how secure it is. I have some metal paste and will add that to the mix.
Returning to the original problem, I’m going to put everything back now I have properly cleaned it all and see if that really is the problem area. Once the bike was raised up, I suspect that the problem might be elsewhere.
You live and learn.
Now to try and fix the poor throttle response on my Honda CB450 K4.
1998 r850r
1979 r45
1974 r60/6
Still learning

ptjenkins65
Club Member 14
Posts: 123
Joined: Thu Jun 08, 2017 7:49 pm
Country of Residence: United Kingdom
Location: London

Re: Exhausting Studs

Postby ptjenkins65 » Sun Feb 02, 2020 7:59 pm

Hi, no it’s because it went off centre and spun what remained of the stud, which sent me and the drill into a bit of a tizz. The others that drilled out fine have tapped just fine
1998 r850r
1979 r45
1974 r60/6
Still learning

User avatar
Galactic Greyhound
Moderator/Club Member
Posts: 9653
Joined: Sat Aug 28, 2010 11:26 pm
Country of Residence: Scotland
Location: Dumfries

Re: Exhausting Studs

Postby Galactic Greyhound » Sun Feb 02, 2020 10:41 pm

What happened re the studs with the nuts welded on by your friend?
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

ptjenkins65
Club Member 14
Posts: 123
Joined: Thu Jun 08, 2017 7:49 pm
Country of Residence: United Kingdom
Location: London

Re: Exhausting Studs

Postby ptjenkins65 » Tue Feb 04, 2020 8:06 am

Good morning. They would not budge, just sheared off a bit lower down. I had squirted in some liquid wrench as they were welded, then waited for them to cool down. The following day iIheated the casing around the studs to 200 c but absolutely nothing doing.
I reassembled last night with the new studs in, but now she won't start, doesn't seem to want to catch. The battery is on charge and I will have try again later .
I think I have found the source of the leak though. As I said, iIhad cleaned everything really carefully to see where the oil was coming from. I think is coming out from the left hand cam chain tensioner. I had updated the right hand to the improved version a couple of months ago, could that have done anything?
Hopefully that is the end of the leak. I will see later on I guess.
1998 r850r
1979 r45
1974 r60/6
Still learning

King Herald
Forum User
Posts: 815
Joined: Wed Apr 05, 2017 3:24 pm
Country of Residence: United kingdom
Location: Midlands.

Re: Exhausting Studs

Postby King Herald » Tue Feb 04, 2020 9:18 am

Left hand cam tensioner is on top, hard to see behind the injector. I had a serious leak from mine when riding one day, pumped out half my engine oil. :sad:
1997 BMW R1100R
1993 Honda Transalp 600

User avatar
keiththeoutfitter1
Club Member 14
Posts: 835
Joined: Mon Feb 18, 2013 11:17 pm
Country of Residence: United Kingdom
Location: East Yorkshire

Re: Exhausting Studs

Postby keiththeoutfitter1 » Tue Feb 04, 2020 10:22 am

If the studs were arc welded, did you disconnect the battery first?
R1200RT
K1100RS + EZS Rally Sidecar
BMW K75C


Return to “Oilhead (R1100/1150/Cruiser) Q&A's”

Who is online

Users browsing this forum: No registered users and 6 guests