« previous next »
Pages: [1]   Go Down

Author Topic: bore size 63,6 on a cb750??  (Read 1145 times)

0 Members and 1 Guest are viewing this topic.

Offline KirkBurner

  • Enthusiast
  • **
  • Posts: 139
bore size 63,6 on a cb750??
« on: January 25, 2014, 12:51:11 AM »
I have read what I can here and on the SatanicMechanic site.

any tips on what kind of pistons the PO has been using?

and I thinking of upgrading to this kit:
Cycle X 12 1/2 Plus 836cc Piston Set

any other suggestions?
Logged

Offline KirkBurner

  • Enthusiast
  • **
  • Posts: 139
Re: bore size 63,6 on a cb750??
« Reply #1 on: January 25, 2014, 07:36:22 AM »
Found out I have a 812 kit, havent measured wear yet...

would I still be able to get rings for them?
Logged

Offline KirkBurner

  • Enthusiast
  • **
  • Posts: 139
Re: bore size 63,6 on a cb750??
« Reply #2 on: January 25, 2014, 07:40:41 AM »







From what you see here, is there any straight up diagnosis?
should there be even carbon buildup?
Logged

Offline seanbarney41

  • not really that much younger than an
  • Really Old Timer ...
  • *******
  • Posts: 11,210
Re: bore size 63,6 on a cb750??
« Reply #3 on: January 25, 2014, 08:35:16 AM »
Quote from: KirkBurner on January 25, 2014, 07:36:22 AM
Found out I have a 812 kit, havent measured wear yet...

would I still be able to get rings for them?
not easily, but it depends on the exact manufaturer.  I have a set made by Honda's oem piston maker (forgot the name).  They are merely 2nd oversize cb350twin pistons, so if you can find those, you are in luck.  Boretech(specializes in race parts for cb350twins)had them at one time, but were out of stock last I checked a couple years ago.  At least a couple other companies sold piston kits this size back in the day, Yoshimura, and, I think?, Action Fours and Henry Abe?
Logged
If it works good, it looks good...

Offline LesterPiglet

  • Old Timer
  • ******
  • Posts: 4,045
  • 1977 CB550F2
Re: bore size 63,6 on a cb750??
« Reply #4 on: January 25, 2014, 08:56:13 AM »
David Silver does various rings for the 350 twins.
Logged
'Then' and 'than' are completely different words and have completely different meanings. Same with 'of' and 'have'. Set and sit. There, their and they're. Draw and drawer. Could care less/couldn't care less. Bought/brought FFS.


Les Ross.            Certified by a Professional

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 15,040
  • Bought her new 4/75
Re: bore size 63,6 on a cb750??
« Reply #5 on: January 25, 2014, 11:37:36 AM »
Looks like you DO need rings. Lots of oil but check the valve guides too.

If the pistons have PopY on them it is a Yoshimura 812 kit. 64mm. They use the 68+ CB350 twin cylinder rings. 
Logged
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 16,509
  • Bike almost back to the 70's 2015
Re: bore size 63,6 on a cb750??
« Reply #6 on: January 25, 2014, 11:49:19 AM »
Logged
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 KirkBurner

  • Enthusiast
  • **
  • Posts: 139
Re: bore size 63,6 on a cb750??
« Reply #7 on: January 25, 2014, 01:14:45 PM »
I have the POP.Y stamp or cast...

Digging the feedback guys...

I love the copper gaskets.. Easy cleaning... ;)
Logged

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,046
Re: bore size 63,6 on a cb750??
« Reply #8 on: January 25, 2014, 06:13:52 PM »
812. Std rings.. A set on ebay right now...
Logged
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way
Pages: [1]   Go Up
« previous next »