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Finned Exhaust Nut Removal

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Logan Finn
(@logan-finn)
Posts: 4
Active Member Customer Registered
Topic starter
 

Hello All,

First post on here, please let me know if I am in the wrong place to ask this.

Working on my 1981 R100CS and am having some real trouble getting the finned exhaust nuts loose. Any advice? 

Thanks!

Logan

 
Posted : 02/12/2024 16:23
Richard W
(@wobbly)
Posts: 2545
Member
 

Welcome, Logan !

• First of all, you need the correct exhaust nut spanner. The shop version is a cast steel wrench about 12" long. Modern home versions are stamped or machined steel which are usually fitted to the end of a socket set ratchet or "pull bar".

 

• Second thing is more in the realm of prevention. That is, each time the exhaust nut is installed, a fresh layer of Never-Seize (or brand name Never-Seez) has to be applied to the threads on the exhaust spigot of the cyl head. And not just any anti-seize compound, but some really high temp stuff. Chris Harris prefers the copper-based, I use the "Nuclear Grade" compound.

If that prevention wasn't done the last time the nut was removed, then the only way may be to use a Dremel tool with a cut-off wheel to cut the aluminum nut in 2 or 3 places and remove it in pieces. I believe Chris has a YouTube video to guide you on this very subject.

https://www.youtube.com/watch?v=ZRXKC9Yxfug

 

Hope this helps.

Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.

 
Posted : 02/13/2024 04:40
James Strickland
(@8053)
Posts: 421
Reputable Member
 

Richard's advice is spot-on correct. I would simply reinforce the notion that if the finned nut does not spin off easily by hand after using the correct spanner to break it loose, DO NOT force it. 

This post was modified 3 months ago by James Strickland

former Airmarshal, IL.

 
Posted : 02/13/2024 06:26
Logan Finn
(@logan-finn)
Posts: 4
Active Member Customer Registered
Topic starter
 

@wobbly I have the at-home version of this tool pictured on the right side in your post, just haven't figured out how to get some more leverage on there. Funny enough, I just watched that Chris Harris video of him removing the nut with a cut-off wheel and was hoping to avoid that, but the bike has been sitting for about 8 years now (maybe longer) so i may have to go in that direction. Thank you for the resources!!

 
Posted : 02/13/2024 09:40
Richard W
(@wobbly)
Posts: 2545
Member
 

Posted by: @logan-finn

@wobbly I have the at-home version of this tool pictured on the right side in your post, just haven't figured out how to get some more leverage on there.

You don't want "leverage", you want "sharp impact". That's why Chris is using a rubber hammer to 'shock' the wrench. I suggest you get a rubber hammer or a "dead blow" (shot filled) hammer and do like he does.

You see the aluminum nut has a tendency to gall (basically heat weld) itself to the aluminum exhaust port of the cyl head. If you have too much leverage you'll simply pull the threads right off the cyl head. Then you'll REALLY be in trouble. 

 

Posted by: @logan-finn

Funny enough, I just watched that Chris Harris video of him removing the nut with a cut-off wheel and was hoping to avoid that, but the bike has been sitting for about 8 years now (maybe longer) so I may have to go in that direction. Thank you for the resources!

Time has absolutely zero to do with this. The nut becomes welded in place due to Heat and the close proximity of a similar metal. It's a naturally occurring welding process. 

The Never-Seize works by inserting a different metal between the 2 mating parts. These are typically a paste made with powdered nickel, copper or some other. 

Please don't get "inventive" on us. Do exactly what you see and hear Christ doing and you'll be OK. 

 

Hope this helps.

 

This post was modified 3 months ago by Richard W

Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.

 
Posted : 02/13/2024 12:42
Logan Finn
(@logan-finn)
Posts: 4
Active Member Customer Registered
Topic starter
 

@wobbly 10-4 on that, really appreciate the help. Will update in this thread once I am home again to work on it!

 
Posted : 02/13/2024 16:01
Mike Buhler
(@16813)
Posts: 207
Reputable Member
 

Photos please. 😊 

 
Posted : 02/15/2024 06:39
Logan Finn
(@logan-finn)
Posts: 4
Active Member Customer Registered
Topic starter
 

Sorry for the late late reply with correctly formatted photos. Should be good now, spent last weekend back home to keep pushing away and am only left with engine, wiring harness, and essentially the entire front end (handlebars, forks, etc). Super pleased with the wealth of knowledge gained from working on it this weekend, I left feeling very motivated to finish the job.

Current Sticking Point: I have one wire remaining attached to the engine. Based on the diagrams I've looked at and from what I've gathered on the issue, I think it is the red wire from the starter relay running to the battery but within the harness is another wire that runs into what i believe would be the starter solenoid and motor. How should I go about removing this wire from the motor? My goal was to have the headlight with the wiring harness laid out (similar to those photos of a brain and nervous system attached), but I'm just not positive that I've identified the wire's correct purpose just based on what I'm seeing in the diagrams. 

Let me know if the latter half of this reply belongs somewhere else. Thank you for the info and support!

Cheers!

 
Posted : 04/08/2024 10:22
Steven Rankin
(@14724)
Posts: 197
Estimable Member
 

You should have two red wires coming off the plus side battery post.  The heavy gauge wire is to supply the high current draw to swing the starter motor, and is attached to the front of the starter solenoid.

The lighter gauge wire supplies the power for the bike's ignition, lights and accessories and goes to the starter relay under the gas tank.

I am not quite sure what you mean by how to take off the heavy gauge wire from the front of the solenoid?  There is a threaded post on the solenoid with a nut.  LOL, it is a bear of a location.

Is this an answer to your question?  Good luck, St.

Beware! I do not suffer fools gladly! St.

 
Posted : 04/08/2024 16:58
Richard W
(@wobbly)
Posts: 2545
Member
 

• Nice project. Thanks for the JPEG photo !!

• There are only 3 RED wires on the whole standard bike:

  1. Battery Pos to Starter Relay 87
  2. Starter Relay 87 to Ignition Switch
  3. Ignition Switch to multi-color circuit board
  4. IF you have a fairing, then the Clock is also fed with its own RED wire

Wires 1 and 2 work in tandem to connect the battery to the ignition switch, as shown below. It's a very poor design and IMHO a real weak point of the harness.

If you are building or tweaking a harness, then I highly suggest the addition of a 20A "main" fuse near the battery as noted in the purple text.

• The heavy gauge starter wire runs from the battery Positive terminal to the starter solenoid. If you remove the Starter Cover (2 bolts) then you'll see the attach point at the hex nut. Due to long-term wicking of battery acid under the jacket of the OEM cable and the loss of reliability this will cause, I highly suggest that you replace this 2 ft cable with a new one.

This post was modified 2 months ago by Richard W

Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.

 
Posted : 04/09/2024 03:08
Steven Rankin
(@14724)
Posts: 197
Estimable Member
 

If you do replace the heavy gauge starter wire, be very fussy in bending it to shape as close to the original wire.  There are a couple of spots where if not properly bent it could rub insulation off on the engine covers and short.  St.

Beware! I do not suffer fools gladly! St.

 
Posted : 04/09/2024 07:10

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