Author Topic: exhaust flange torque  (Read 1700 times)

0 Members and 1 Guest are viewing this topic.

Offline lash

  • Expert
  • ****
  • Posts: 951
exhaust flange torque
« on: September 28, 2016, 07:14:21 AM »
69 cb750... anyone know what the torque should be for the exhaust flange bolts?
Analog mind in a digital world..

Offline Bodi

  • Really Old Timer ...
  • *******
  • Posts: 5,761
Re: exhaust flange torque
« Reply #1 on: September 28, 2016, 07:33:10 AM »
Pretty sure they are 6mm - steel into the alloy head... so not much or you strip the alloy threads. There is a spec in the common service manual but I don't torque these to a spec, I tighten until the header gasket gives a little and then check for looseness after a few heat cycles. I haven't had them come loose after doing this.

Offline lash

  • Expert
  • ****
  • Posts: 951
Re: exhaust flange torque
« Reply #2 on: September 28, 2016, 07:39:19 AM »
Makes sense, thanks
Analog mind in a digital world..

Offline Deltarider

  • Really Old Timer ...
  • *******
  • Posts: 8,538
  • I'm back
Re: exhaust flange torque
« Reply #3 on: September 28, 2016, 11:30:26 AM »
Just tighten by hand until gaskets are compressed somewhat and then stop. In case you have to redo it a bit, you'll still have gasket left that still can be compressed a bit further. Did it like this myself the other day. Torque wrenches on 6mm is madness, a mistake is easily made. It's not worth it.
CB500K2-ED Excel black
"There is enough for everyone's need but not enough for anybody's greed."

Offline jonda500

  • I may be crazy but I'm not stupid!
  • Master
  • *****
  • Posts: 1,942
  • With our thoughts we make the world (Monkey Magic)
Re: exhaust flange torque
« Reply #4 on: September 29, 2016, 08:16:15 PM »
Just tighten by hand until gaskets are compressed somewhat and then stop. In case you have to redo it a bit, you'll still have gasket left that still can be compressed a bit further. Did it like this myself the other day. Torque wrenches on 6mm is madness, a mistake is easily made. It's not worth it.

+1!!!!
Remember that an ignoramus is only someone who doesn't know something you just learned yesterday!

A starter clutch thread:
http://forums.sohc4.net/index.php/topic,122084.0.html
1972 CB500K1 original 4 owner bike
1972 CB500K1 returned to complete/original condition
1975 CB550F built from parts - project thread:
http://forums.sohc4.net/index.php/topic,149161.msg1711626.html#msg1711626
197? CB500/550 constructing from left over parts
1998 KTM 380 (two stroke) recent impulse buy, mmmm...

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 21,527
  • Saver of unloved motorcycles.
Re: exhaust flange torque
« Reply #5 on: September 30, 2016, 09:56:04 PM »
 Nonsense, tighten till it strips and back it off a half turn. That said, someone ripped the thread lug off a head recently, that one was apparently bottomed out, beware of that issue.
 In all seriousness I agree with the above advise.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline Airborne 82nd

  • Expert
  • ****
  • Posts: 828
Re: exhaust flange torque
« Reply #6 on: October 01, 2016, 04:23:01 AM »
Have you considered replacing them with studs & nuts like my 1978 750K But that's just me.
imho

Offline lash

  • Expert
  • ****
  • Posts: 951
Re: exhaust flange torque
« Reply #7 on: October 01, 2016, 06:03:14 AM »
No, I'm trying to stay as close to stock as I can.
Analog mind in a digital world..