Author Topic: 1976 K6 features  (Read 687 times)

0 Members and 1 Guest are viewing this topic.

Offline Artie

  • Full Member
  • *
  • Posts: 43
1976 K6 features
« on: June 16, 2016, 07:18:08 PM »
Read in timeline evolution that K6 model had stronger swing arm and detuned engine any insight as to detuning was accomplished??

Offline chewbacca5000

  • I polish covers!
  • Old Timer
  • ******
  • Posts: 3,536
Re: 1976 K6 features
« Reply #1 on: June 16, 2016, 07:28:23 PM »
Read in timeline evolution that K6 model had stronger swing arm and detuned engine any insight as to detuning was accomplished??

It was made quieter for touring riders so they worked hard to keep the noise down.  In doing so HP was lost do to more friction.  For example on the early models the rocker shafts were allowed to pivot which made more HP, but more noise.  Lot louder tapping sound.  The touring crowd did not care for that noise as the windjammers reflected it back to the rider.

I would encourage you to buy Hondaman's book he talks all about it.  Has a thread somewhere about HP theves through he years.

Offline ekpent

  • Really Old Timer ...
  • *******
  • Posts: 13,512
  • To many bikes-but lookin' for more
Re: 1976 K6 features
« Reply #2 on: June 17, 2016, 07:23:16 AM »
 After around 71 the 341 pipes got more restrictive and the jetting got smaller that by 75-76 they were using a 105 main when  1970/71 had a 120. They wanted the engines to have more torque then revs so the guys adding the windjammers and bags etc would have a little better low end pull. A gas crisis was also hitting at the time and fuel efficiency was becoming a big deal. Any old timers remember the lines ?? 
  As for the swingarm I believe they have a little bit of a different bushing.
« Last Edit: June 17, 2016, 07:29:55 AM by ekpent »

Offline Jonesy

  • Shop Rat
  • Old Timer
  • ******
  • Posts: 2,648
  • "Damn! These HM300 Pipes Are Expensive!!!"
Re: 1976 K6 features
« Reply #3 on: June 17, 2016, 07:58:15 AM »
The earliest 750's had HM300 mufflers, which were basically an open megaphone with a glass-pack baffle. Later models used the HM341 mufflers with internal metal baffles. Earlier versions of the 341 had 5 baffles, later versions had 7. On the backside of the pipe you can see the spot welds for each baffle. You can count them to see how many you have.
"Every time I start thinking the world is all bad, then I start seeing people out there having a good time on motorcycles; it makes me take another look." -Steve McQueen

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 15,597
  • Bike almost back to the 70's 2015
Re: 1976 K6 features
« Reply #4 on: June 19, 2016, 01:22:43 AM »
I have also read about stronger swingarm.
My original K6 swingarm got its chain guard brackets broken due to a broken chain. Foind a restored K2 arm that does not look weaker. It has no grease nipple that never used, K6 have an angled design close to the bolt.
I cannot see that my K6 is weaker with k2  swingarm.
I think I have compared both with photos in a thread when I assembled the bike fall 2013
The very first 4-4 pipes were "Lotus Root" open racing style, right?
300 replica is a nice upgrade with very nice sound. Diffusers rests in a box in my garage, for vehicle test only to ensure valid registration doc.
« Last Edit: June 19, 2016, 01:42:38 AM by PeWe »
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