Author Topic: Seal installation question  (Read 866 times)

0 Members and 1 Guest are viewing this topic.

Offline timtune

  • Enthusiast
  • **
  • Posts: 188
Seal installation question
« on: November 12, 2021, 09:08:05 AM »
Just about to mate the cases of my 750 and the new seal for he points end of the crank has me confused.
The seal has an integral metal washer. I'm sure whether that faces in or out.

I think out makes sense because otherwise it rubs metal to metal with end of the crank. But then I'm the writing on seal faces out.
Thanks for any help to clear this up.

Offline timtune

  • Enthusiast
  • **
  • Posts: 188
Re: Seal installation question
« Reply #1 on: November 12, 2021, 09:20:00 AM »
After some searching it looks like Hondaman already answered this in the past

Yes, you can!
Engine out (that's the hard part), new gaskets for the side covers (tranny cover, alternator cover, shifter cover) will be needed. And the crankshaft seal, a new one for sure. Get the kind that has the metal backing disc inside (engine side), they last much longer (like forever).

I guess my rubbing metal to metal is not a thing.

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 15,529
  • Bike almost back to the 70's 2015
Re: Seal installation question
« Reply #2 on: November 12, 2021, 11:02:07 AM »
There is a groove in cases where that metal washer part of the crank seal fits. It is the inner part, other side towards ignition.
When fiddling with it you'll see it can only fit one way.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 19,816
  • Saver of unloved motorcycles.
Re: Seal installation question
« Reply #3 on: November 12, 2021, 09:48:28 PM »
 It's so cool there always seems to be a person that recently dealt with whatever you need to know. That person may be anywhere in the world.
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 PeWe

  • Really Old Timer ...
  • *******
  • Posts: 15,529
  • Bike almost back to the 70's 2015
Re: Seal installation question
« Reply #4 on: November 13, 2021, 11:19:01 AM »
Do not forget to lube the seal lips where in contact with crank to not cause initial wear.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967