ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 04-01-2013, 10:30 PM   #1
GCCR OP
Gnarly Adventurer
 
GCCR's Avatar
 
Joined: Feb 2013
Location: Rocklin, CA
Oddometer: 180
Stripped Exhaust Threads

Newbie here. Just started a teardown on a 82 R65. I was in the process of removing the exhaust nuts that were on pretty snug. I shot it with PBR to break them loose. But after a while, when nuts were removed I noticed the threads on the right cylinder were all but gone. Any tips on repairing them? Thanks.


GCCR
GCCR is offline   Reply With Quote
Old 04-01-2013, 10:42 PM   #2
Warin
Retired
 
Joined: Aug 2012
Oddometer: 1,701
That is a frequent problem .. you should have cut the nuts in half - far cheaper!

See http://www.motobins.co.uk/motobins-hints-and-tips.php scan down for "Exhaust Port Nuts" for a full description.. suggest your read other bits from that site too.

It is possible to repair them ..but lots of $$$.

Google is your friend .. found http://www.advrider.com/forums/showthread.php?t=236601
Warin is online now   Reply With Quote
Old 04-02-2013, 12:43 AM   #3
batoutoflahonda
Beastly Adventurer
 
Joined: Aug 2007
Location: Easton Wa
Oddometer: 1,364
check it

http://www.advrider.com/forums/showthread.php?t=236601

http://www.price.gmxhome.de/BMW-V2-A...p-Details.html
__________________
It's eight and a half gallons of gas; and an engine. What more do you need?-- BMW R80G/S

Save lives. Legalize lane sharing.

Cow eyes don't glow.
batoutoflahonda is offline   Reply With Quote
Old 04-02-2013, 04:32 AM   #4
Plaka
Brevis illi vita est
 
Joined: Jun 2010
Oddometer: 4,581
Quote:
Originally Posted by GCCR View Post
Newbie here. Just started a teardown on a 82 R65. I was in the process of removing the exhaust nuts that were on pretty snug. I shot it with PBR to break them loose. But after a while, when nuts were removed I noticed the threads on the right cylinder were all but gone. Any tips on repairing them? Thanks.


GCCR
Talk to Carl...around here somewhere.
Plaka is offline   Reply With Quote
Old 04-02-2013, 07:27 AM   #5
d mc gee
Studly Adventurer
 
d mc gee's Avatar
 
Joined: Nov 2006
Location: Upper Sandusky, OH
Oddometer: 803
Quote:
Originally Posted by GCCR View Post
Newbie here.. I shot it with PBR to break them loose. Thanks.


GCCR
PBR is a "social lubricant", it is a very poor lubricant other wise. Except the next morning.

__________________
If it wasn't for my graceful wife, my dumbass would be banned already
Doug Mc Gee

01 1150 GS
84 R100RS
74 XL350
d mc gee is offline   Reply With Quote
Old 04-02-2013, 08:48 AM   #6
Kt-88
I like everything.
 
Kt-88's Avatar
 
Joined: Sep 2012
Location: SLC area, Utah
Oddometer: 459
Quote:
Originally Posted by d mc gee View Post
PBR is a "social lubricant", it is a very poor lubricant other wise. Except the next morning.

Ha!
Kt-88 is offline   Reply With Quote
Old 04-02-2013, 09:29 AM   #7
Jim Day
full manic mechanic
 
Jim Day's Avatar
 
Joined: Mar 2012
Location: So. Cal.
Oddometer: 642
Quote:
Originally Posted by GCCR View Post
...... when nuts were removed I noticed the threads on the right cylinder were all but gone. Any tips on repairing them?

There are a few ways to repair this. Can you post some pics so we can see how bad it is. Where are you located, are there any good metal fabricators or machine shops in your area?

Jim Day screwed with this post 04-02-2013 at 09:39 AM
Jim Day is online now   Reply With Quote
Old 04-02-2013, 10:20 AM   #8
Jim Day
full manic mechanic
 
Jim Day's Avatar
 
Joined: Mar 2012
Location: So. Cal.
Oddometer: 642

You have to respect the elegance and ingenuity of Walter's solution, but though I personally love it, I find his adapter to be well kinda.... Well..... ugly on the bike.

In itself off the bike it's beautiful, on the bike not so much as it doesn't match, looks small and stuck on. A 10 for it's direct simplicity and effectiveness, 6 for aesthetics as they simply do not match the aesthetics of the engine.

That said.... If I was going to go that route, I'd use his connection at the head but then I'd take the original exhaust port nut, cut the threaded portion off weld in some metal on each side between the fins and drill it to match his attachment flange.

I know everyone can't weld aluminum like I can but you should be able to find a shop that can do this.

Essentially you could still use his clamp at the head, but couple it to a finned flange that works the same way but matches the original exhaust nut configuration.

It' would be like a custom BMW version of a the old KZ Kawa exhaust clamp.


Or essentially like this one I just Photoshopped:


Easy enough to make and it would match the other side.

Jim Day screwed with this post 04-02-2013 at 11:31 AM
Jim Day is online now   Reply With Quote
Old 04-02-2013, 10:59 AM   #9
GCCR OP
Gnarly Adventurer
 
GCCR's Avatar
 
Joined: Feb 2013
Location: Rocklin, CA
Oddometer: 180
Very nicely done!
GCCR is offline   Reply With Quote
Old 04-02-2013, 11:11 AM   #10
GCCR OP
Gnarly Adventurer
 
GCCR's Avatar
 
Joined: Feb 2013
Location: Rocklin, CA
Oddometer: 180
Quote:
Originally Posted by Warin View Post
That is a frequent problem .. you should have cut the nuts in half - far cheaper!

See http://www.motobins.co.uk/motobins-hints-and-tips.php scan down for "Exhaust Port Nuts" for a full description.. suggest your read other bits from that site too.

It is possible to repair them ..but lots of $$$.

Google is your friend .. found http://www.advrider.com/forums/showthread.php?t=236601
Thanks, Warin!
GCCR is offline   Reply With Quote
Old 04-02-2013, 12:06 PM   #11
GCCR OP
Gnarly Adventurer
 
GCCR's Avatar
 
Joined: Feb 2013
Location: Rocklin, CA
Oddometer: 180
Quote:
Originally Posted by Jim Day View Post
There are a few ways to repair this. Can you post some pics so we can see how bad it is. Where are you located, are there any good metal fabricators or machine shops in your area?
Hi Jim here are the pics you asked about. I'd be interested in anyone in CA that could repair this.


GCCR is offline   Reply With Quote
Old 04-02-2013, 12:20 PM   #12
Jim Day
full manic mechanic
 
Jim Day's Avatar
 
Joined: Mar 2012
Location: So. Cal.
Oddometer: 642
OK.... You got me thinking, and think I may of just figured out a much cheaper and easier way to do this if there is still some threads at the cylinder.

Say you take a standard BMW finned exhaust nut.



Then take a hacksaw and cut it completely through on one side, leaving a gap.

Find a high strength stainless steel exhaust clamp that exactly fits around the non-finned portion of the nut. There are a number of styles to choose from this type would be ideal.


If sized correctly this style would work as well.




Take a triangular file and clean up the threads that are left at the cylinder so there are no large burs or metal that sticks out then coat it with anti-seize.

Slide your stainless clamp on the nut, slide the nut on your exhaust pipe and hand tighten it in place just like you would normally. Now you want to tighten the clamp around the nut to the point you can no longer turn in by hand, this will effectively reduce the diameter of the nut giving you the maximum thread contact. Put a wrench to the nut and tighten it just enough to get a seal, without stripping or destroying what remains of the threads. Now tighten the clamp tight around the nut to compress and lock it in place.

Once tightened in place this would hold in place mechanically the same way as Walter's solution, but you wouldn't tighten the pipes connection to the cylinder head further. It might be a little harder to get a good seal, but once you get it, it should work at a fraction of the expense.

Jim Day screwed with this post 04-03-2013 at 04:18 AM
Jim Day is online now   Reply With Quote
Old 04-02-2013, 12:29 PM   #13
Jim Day
full manic mechanic
 
Jim Day's Avatar
 
Joined: Mar 2012
Location: So. Cal.
Oddometer: 642
Quote:
Originally Posted by GCCR View Post
Hi Jim here are the pics you asked about. I'd be interested in anyone in CA that could repair this.b

Ouch!!! That's pretty ugly, and it doesn't look right at all. It looks like it was stripped before and someone used some kind of high temp adhesive on it to get it to hold and seal. That gray gook and stuff with bubbles in it should not be there at all, it's not aluminum.

In other words you might not of been the one that stripped it.

I'm in LA.

I have both a TIG and Mig set up for Aluminum here. I've also have access to a shop in Oxnard.
I'm not really looking for work but I'd be happy to look at it up close. If you want to bring it by I'm sure we could figure something out.

Jim

Jim Day screwed with this post 04-02-2013 at 02:27 PM
Jim Day is online now   Reply With Quote
Old 04-02-2013, 01:00 PM   #14
CanadaBiker
Gnarly Adventurer
 
Joined: Sep 2012
Location: Southern Ontario, Canada
Oddometer: 181
so I'm getting a bit freaked out by seeing these knackered threads. I'll be changing the exhaust on my new-to-me R100/7. Should I just cut the nuts off if they are the slightest bit stuck? I was planning on putting new nuts on anyway.
__________________
2005 Suzuki DR650, 1987 BMW R80
CanadaBiker is offline   Reply With Quote
Old 04-02-2013, 02:48 PM   #15
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 8,403
You need the proper tool for removing the exhaust flange nut. When using the correct tool if it starts to feel stuck you should feel it and at that point cut the nut off. These threads are to be coated with anti-seize. Many recommend other brands. I use the Permatex, silver one.

The best repair does seem to be welding new Aluminum and then cutting new threads on the head. This is a really big thread and the die for cutting it is probably not too common. I see the die for sale on Ebay sometimes and it is a $100 I think plus shipping from Germany. I hope you can do this. Maybe there is some other way to cut new threads or the die is not uncommon like I suspect.

It does look like that head has been repaired before.

Looks of the two part flange repair aside it does work.
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

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 On

Forum Jump


Times are GMT -7.   It's 01:28 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014