« previous next »
Pages: [1]   Go Down

Author Topic: Advice on valve cover hole  (Read 702 times)

0 Members and 1 Guest are viewing this topic.

Offline lparm

  • Full Member
  • *
  • Posts: 2
Advice on valve cover hole
« on: November 07, 2018, 05:42:49 AM »
I am restoring a 1978 K8 and found this hole in the valve cover under the breather cover.
Anyone seen this before? Should it be welded? replaced?
Logged

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,357
Re: Advice on valve cover hole
« Reply #1 on: November 07, 2018, 05:56:43 AM »
Thats how they are cast, nothing to worry about. The valvetrain breathes through that area, and with the breather cover on, you won't have any issues.
Logged
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline lparm

  • Full Member
  • *
  • Posts: 2
Re: Advice on valve cover hole
« Reply #2 on: November 07, 2018, 06:56:50 AM »
thats good news, thanks
Logged

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,289
Re: Advice on valve cover hole
« Reply #3 on: November 07, 2018, 06:58:42 AM »
Yep...its normal.
Logged
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline Motorcycle jones

  • Full Member
  • *
  • Posts: 16
Re: Advice on valve cover hole
« Reply #4 on: November 07, 2018, 10:41:29 AM »
That is the improved valve cover design .
The 1978 model had 22 such improvements over the earlier models.
Logged

Offline ekpent

  • Really Old Timer ...
  • *******
  • Posts: 13,508
  • To many bikes-but lookin' for more
Re: Advice on valve cover hole
« Reply #5 on: November 07, 2018, 04:12:39 PM »
Quote from: Motorcycle jones on November 07, 2018, 10:41:29 AM
That is the improved valve cover design .
The 1978 model had 22 such improvements over the earlier models.
  Hey MJ. Is there a published list of those 22 changes somewhere to read ? This is not a call out or anything, it would just be fun to read up on all the differences since I don't do 750's later then 1976 generally as a rule.
Logged
Pages: [1]   Go Up
« previous next »