Contact Overland Solutions for all your custom modifications and setup for overland travel.               Discover the extraordinary with Compass Expeditions.

Go Back   The HUBB > Technical, Bike forums > BMW Tech
Exhaust finned nut removal Exhaust finned nut removal
Register FAQ Calendar Search Today's Posts Mark Forums Read

BMW Tech BMW Tech Forum - For Questions specific and of interest to BMW riders only. Questions comparing which bike is best etc go in the "Which Bike" forum.
With more than 58 destinations worldwide, Edelweiss Bike Travel is Number 1 in guided motorcycle tours!
Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 26 Sep 2008
Registered Users
HUBB regular
  
Join Date: Jan 2005
Posts: 25
Exhaust finned nut removal
I need to remove both exhaust finned nuts so I can replace push rod tubes. They havent been removed for years so I dont even want to attempt to unscrew them. what would be the best way to cut them off - using a dremmel drill cutting tool of drilling a row of perferation holes along the width and finishing off with a chisel? any ideas? cheers, mark
Reply With Quote
  #2  
Old 26 Sep 2008
Giacomo's Avatar
Registered Users
Veteran HUBBer
  
Join Date: Nov 2004
Location: Weird north East bit of Italy
Posts: 156
I thought mine would never come off, when I bought the bike it was clear that they might never have come off since they were first put there..

However surprisingly enough after keeping the threads soaked in penetrating oil for a week, and heating them a little bit, they both came off very easily, using the right tool and a couple of gentle taps with a mallet.

(obviously if they don't unscrew easily then your original idea is the best one)

I also had a little hacksaw ready, a dremel would clearly be much better, the metal is actually quite soft so a careful cut and a couple of whacks with a chisel should be enough to break them off......in a worst case scenario

Hope this helps.

ciao.
Last edited by Giacomo; 28 Sep 2008 at 18:14.
Reply With Quote
  #3  
Old 26 Sep 2008
palace15's Avatar
Gold Member
Veteran HUBBer
  
Join Date: Feb 2005
Location: LONDONISTAN, England
Posts: 936
Don't even attempt to unscrew them! my 100/7 had not been touched for years, the nuts appeared to be unscrewing nicely, they were with the thread no longer attached to the cylinder head but well embedded in the nut thread! When I had to remove them on my R80gs i took no chances and cut them off/chisled without even showing them the spanner, new exhaust nuts are far cheaper and less agrrevation than having new inserts put in the head, as well as having new nuts anyway, put plenty of copper slip/gold grease on them and if you can remember or can be bothered just make sure they 'run free' and even regrease at every semi major service.
__________________
'He who laughs last, was too slow to get the joke'

Reply With Quote
  #4  
Old 26 Sep 2008
Registered Users
Veteran HUBBer
  
Join Date: May 2006
Location: Bribie Island Australia
Posts: 458
I'd always try and get them off the way they were designed to come off before resorting to cuts and chisels. Remember that any serious damage to those threads will make the head useless, if you deform them with a chisel its almost impossible to get the fin nuts to go back in.

Its easy enough to make up (or have one made) the tool needed to unscrew them.

The BMW tool looks like a big open ended spanner with three studs that go into the fins.

A pair of Stilson wrenches at 90 degrees will also do the job. If you use Stilsons you need to put hardwood wedges between the fins to increase the number of fins that take the torque.

Having a 1m length of pipe over the spanner ends helps to increase the leverage, you'll probably find that they come loose quite easily with a long lever.

Use plenty of penetrating oil and try some spray CO2 to contract the fin nut as well.
Reply With Quote
  #5  
Old 26 Sep 2008
Registered Users
HUBB regular
  
Join Date: Oct 2006
Posts: 50
Quote:
Originally Posted by RogerM View Post
Remember that any serious damage to those threads will make the head useless
Not the case.
The chap who "unleaded" my 78 R80 heads also machined down the damaged exhaust threads & fitted some really nice brass threaded sleaves, pinned to stop them turning.

Also I've seen some clamps (can't remember where! German manufacturer I think) that are split with a pinch bolt, designed specifically for damaged threads.
Reply With Quote
  #6  
Old 27 Sep 2008
Giacomo's Avatar
Registered Users
Veteran HUBBer
  
Join Date: Nov 2004
Location: Weird north East bit of Italy
Posts: 156
Quote:
Originally Posted by Carl P View Post
Not the case.

Also I've seen some clamps (can't remember where! German manufacturer I think) that are split with a pinch bolt, designed specifically for damaged threads.
I also read about those a while back but I can't find the link. Motorworks sells something similar :

Motorworks - BMW Motorcycle Spares - Products **R45/50/60/65/75/80/90/100 (2 valve)
Reply With Quote
  #7  
Old 29 Sep 2008
Registered Users
New on the HUBB
  
Join Date: May 2008
Location: London
Posts: 14
Quote:
Originally Posted by RogerM View Post
I'd always try and get them off the way they were designed to come off before resorting to cuts and chisels. Remember that any serious damage to those threads will make the head useless, if you deform them with a chisel its almost impossible to get the fin nuts to go back in.

l.
Rubbish - I've removed hundreds of exhaust nuts over the years just by hitting with a sharp bolster. the metal is as soft as cheese, and two good hits and they're split and then they simply unscrew.
Never had any damage to the thread on the head. It's cheaper destroying the fins than damaging the thread on the heads.
Once the new ones are fitted loosen them off and lube with copperslip once a year.
Last edited by steptoe; 30 Sep 2008 at 10:46.
Reply With Quote
  #8  
Old 29 Sep 2008
Registered Users
HUBB regular
  
Join Date: Jan 2005
Posts: 25
Thanks everyone, went for the hacksaw and chisel option - came off no probs.
Reply With Quote
  #9  
Old 5 Oct 2008
Ekke's Avatar
HU CanWest Meeting Organiser
Veteran HUBBer
  
Join Date: Jun 2000
Location: Redwood Meadows, AB, Canada
Posts: 319
Thumbs up Walter Price's exhaust nuts worked great
I had buggered up the threads on my R100GS before our big trip and ended up buying Walter Price's exhaust nut replacements. Cheaper than getting the threads repaired but more importantly, I can take off the exhaust using only an Allen key. Definitly a plus when in the middle of nowhere! Here is a link to his website:

BMW V2 Airhead Exhaust Clamp repair
__________________
Ekke Kok

'84 R100RT 141,000 km (Dad's!)
'89 R100GS 240,000 km (and ready for another continent)
'07 R1200GS Adventure (sitting in Germany waiting to go RTW in 2012)


www.ekke-audrey.ca
Reply With Quote
  #10  
Old 7 Nov 2008
Registered Users
Veteran HUBBer
  
Join Date: Jun 2005
Location: Cape Town / South Africa
Posts: 223
Quote:
Originally Posted by steptoe View Post
Rubbish - Once the new ones are fitted loosen them off and lube with copperslip once a year.
BMW assembly paste will keep them from siezing for many years. I recently bought a 89 mod R80GS with very low milage and were the first person to remove the exhuast after they were installed at the factory. They came loose with only a light knock of the exhuast nut wrench.
On two occasions have I seen copperslip been used and within 6 months from fitting the exhuast nuts they were siezed in place and damaged the threads on the cylinderheads in the process of removing them. DO NOT USE COPPERSLIP! and do not loosen them every year to make sure they are fine, this only increase the risk of damage.
Apply assembly paste, part no. 18 21 9 062 599, to the thread of both the nut and cylinderhead and leave them allone till the next time it become nessasary to remove the exhuast system.
Make sure the threads is clean and free from old and hardened lubricants.
Reply With Quote
  #11  
Old 9 Jan 2009
Gold Member
Veteran HUBBer
  
Join Date: Feb 2001
Posts: 113
"On the two occasions I've seen Copperslip used...."

I've owned a BMW R100/7 for about ten years and cut the finned nuts off when I first had the bike. Using new nuts I loosen the nuts every year and coat the threads with Copperslip. They've NEVER EVER SEIZED in ten years, OK?
Reply With Quote
  #12  
Old 10 Jan 2009
Registered Users
Veteran HUBBer
  
Join Date: Oct 2002
Location: Stockholm - Sweden
Posts: 309
Do you have the proper tools ?
If not.
- Get them.

When you have the bike on the central stand it will tip over towards you when you try to unscrew the right nut, and you will lift the bike when you try to remove the left nut.
>>This is normal.<<

If you feel hesitant - cut the nuts!
Be careful not to damage the threads though.

Riding in salt and sleet will get these nuts stuck real bad -
When the nuts oxidize stuck - you will ripp the threads if you attempt to unscrew them!!! And to fix such damages is far more expensive than just cutting the nuts.

When you reinstall these nuts - do lubricate them, generously, with Omega 99 (or equivallent 1000-1200'C paste). I know people recommend cupper-slip/paste, but that will not last even one winter in the salt and sleet (+/-0'C to -8'C).

Lubricating, and heating prior to an attempt to losen the nuts - is an obvious precaution (I have never done it though).


# # #
DO NOT use poly-plier(? english term/word?), chissel, or any "inventive" gadget - in such a case you do better by cutting the nuts!

ONLY Use the proper BMW "claw" or a fair pattern -
__________________
Drive Safely,
Albert
Reply With Quote
Reply

« Previous Thread | Next Thread »

Currently Active Users Viewing This Thread: 1 (0 Registered Users and/or Members and 1 guests)
 
Thread Tools
Display Modes
Linear Mode Linear Mode

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
xt600E head removal Dave dix Yamaha Tech 10 30 Jan 2008 18:37
xtz660.fitting finned rectifier to 1993 model scardemdogz Yamaha Tech 0 23 Feb 2007 12:11
3ja fuel pump removal braindead Yamaha Tech 4 10 Jan 2005 19:51
Cat removal simonrjames BMW Tech 0 31 Dec 2003 18:57
Front Sprocket Removal sjbarrow Yamaha Tech 4 29 May 2001 17:09


All times are GMT +1. The time now is 17:43.

Contact Us - Horizons Unlimited Motorcycle Travellers Website - Archive - Privacy Statement - Top