Author Topic: Andys CB810 K2 road racer- updated 07.24.20 on the road again!  (Read 43391 times)

0 Members and 1 Guest are viewing this topic.

Offline andy750

  • Really Old Timer ...
  • *******
  • Posts: 7,520
So I opened up the K2 carbs tonight and found a few issues...evidence of brass-aluminum corrosion, and carb #3 had a bent float - probably explain why it was the cold cylinder at start up - surprised it wasn’t overflowing at idle. See pics below...

#2

The broken pilot jet







Sent from my iPhone using Tapatalk
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico (CB750K4), 2003 - European Tour (CB750K4), 2004 - SOHC Easy Rider Trip (CB750K4), 2008 - Adirondack Tour 2-up (CB750K4) , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. VStrom DL1000 2003
4. XLR650L 2006

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline andy750

  • Really Old Timer ...
  • *******
  • Posts: 7,520
Explains the #3 plug...that I checked previously


Sent from my iPhone using Tapatalk
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico (CB750K4), 2003 - European Tour (CB750K4), 2004 - SOHC Easy Rider Trip (CB750K4), 2008 - Adirondack Tour 2-up (CB750K4) , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. VStrom DL1000 2003
4. XLR650L 2006

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline jaytee-nz

  • Hot Shot
  • ***
  • Posts: 504
I might be seeing things, but the pilot jet on the right hand carb looks bent to me ?

Offline andy750

  • Really Old Timer ...
  • *******
  • Posts: 7,520
I might be seeing things, but the pilot jet on the right hand carb looks bent to me ?

Never noticed that...Ill take a closer look and let you know!
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico (CB750K4), 2003 - European Tour (CB750K4), 2004 - SOHC Easy Rider Trip (CB750K4), 2008 - Adirondack Tour 2-up (CB750K4) , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. VStrom DL1000 2003
4. XLR650L 2006

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 9,975
  • Big ideas....
That pilot jet does look bent. Were you playing soccer with those carbs Andy??
Owner of the "Million Dollar CB"

Offline andy750

  • Really Old Timer ...
  • *******
  • Posts: 7,520
That pilot jet does look bent. Were you playing soccer with those carbs Andy??

Never touched them!

I may need your help though in extracting the broken one  :-X :-\

I have a spare set of carbs that I am hoping to install tonight and test ride tomorrow morning so will update here with progress.
« Last Edit: July 24, 2020, 06:35:33 am by andy750 »
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico (CB750K4), 2003 - European Tour (CB750K4), 2004 - SOHC Easy Rider Trip (CB750K4), 2008 - Adirondack Tour 2-up (CB750K4) , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. VStrom DL1000 2003
4. XLR650L 2006

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 9,665
  • Bike almost back to the 70's 2015
If the bent looking jet really is bent, the broken jet might have been bent too. Can be why it broke.
Remove the other jets very slow. No quick twist.

Edit: Buy Keihin jets.
« Last Edit: July 24, 2020, 08:53:04 am by PeWe »

Offline andy750

  • Really Old Timer ...
  • *******
  • Posts: 7,520
Ok so...the pilot jet was not bent...optical illusion I think - see pics

All four carbs

Pilot jet on the right looks straight to me


Close up

Arrow points to jet in question



Sent from my iPhone using Tapatalk
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico (CB750K4), 2003 - European Tour (CB750K4), 2004 - SOHC Easy Rider Trip (CB750K4), 2008 - Adirondack Tour 2-up (CB750K4) , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. VStrom DL1000 2003
4. XLR650L 2006

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline andy750

  • Really Old Timer ...
  • *******
  • Posts: 7,520
Switched the carbs and success!!! - no leaks on start up and test ride showed what I have been missing these last few months - snappy throttle, growl of the HM300s, fast acceleration - got it up to speed on the highway and was not disappointed. Smiling again!! Can’t wait for the next ride :)

Thanks for all the comments they really motivated me.

Post-highway ride



Sent from my iPhone using Tapatalk
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico (CB750K4), 2003 - European Tour (CB750K4), 2004 - SOHC Easy Rider Trip (CB750K4), 2008 - Adirondack Tour 2-up (CB750K4) , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. VStrom DL1000 2003
4. XLR650L 2006

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline Alan F.

  • just the essentials
  • Old Timer
  • ******
  • Posts: 4,243
Good news Andy!
Free Fork Swaps and Upgrades info parked at http://sites.google.com/site/alansdocuments/ 

My stalled 750K3 build: http://forums.sohc4.net/index.php?topic=46082.0

Fast moving 750K8 build started 5/17/20
http://forums.sohc4.net/index.php/topic,182592.0.html

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 9,665
  • Bike almost back to the 70's 2015
Quickly done too!

Offline knowsnothing

  • Hot Shot
  • ***
  • Posts: 638
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #286 on: July 28, 2020, 01:26:23 pm »
 Nice work young Andrew
1978 CB750k TBD - getting closer, 811 engine
1978 CB750k Blue - around town beater
1974 CB375F Faded Black - had to have that 6th gear
1976 CB400F Red - in many pieces
1973 CB350F TBD - in many pieces

Offline andy750

  • Really Old Timer ...
  • *******
  • Posts: 7,520
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #287 on: July 28, 2020, 06:19:49 pm »
Thank you Treeve! I was over in your neck of the woods on Saturday morning at 8am....did the Blue Hills-Wollaston Beach loop from mine and back to test ride the K2. Passed with flying colours! Next time Ill shoot you a text before I head over. I was back home by 8:30 before the heat hit.

How is your bike coming along? Running yet? Need any parts?  8)

Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico (CB750K4), 2003 - European Tour (CB750K4), 2004 - SOHC Easy Rider Trip (CB750K4), 2008 - Adirondack Tour 2-up (CB750K4) , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. VStrom DL1000 2003
4. XLR650L 2006

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline knowsnothing

  • Hot Shot
  • ***
  • Posts: 638
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #288 on: July 29, 2020, 11:45:57 am »
Thank you Treeve! I was over in your neck of the woods on Saturday morning at 8am....did the Blue Hills-Wollaston Beach loop from mine and back to test ride the K2. Passed with flying colours! Next time Ill shoot you a text before I head over. I was back home by 8:30 before the heat hit.

How is your bike coming along? Running yet? Need any parts?  8)

Let me know next time for sure. 

The bike is finally running.  I still need to finish the tank and seat, but I have a stock tank and seat on it for now so I can get a few miles on it while i finish.

 Right now i am working on tuning.  It has a hanging idle issue I think is likely due to a lean condition, so I am working on that.  Still need to open it up on a highway, but its nice and peppy so far. I am just pumped it didn't grenade on first start up since i did do most of the work    ;D  . 

1978 CB750k TBD - getting closer, 811 engine
1978 CB750k Blue - around town beater
1974 CB375F Faded Black - had to have that 6th gear
1976 CB400F Red - in many pieces
1973 CB350F TBD - in many pieces

Offline RAF122S

  • I feel like a very very
  • Really Old Timer ...
  • *******
  • Posts: 7,451
  • SOHC4 member # 2605
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #289 on: July 29, 2020, 07:57:55 pm »
Are the felts on the throttle shafts lubed? That can cause a slow return to idle.
David- back in the desert SW!

Offline Stev-o

  • Ain't no
  • Really Old Timer ...
  • *******
  • Posts: 30,112
  • Central Texas
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #290 on: July 31, 2020, 07:12:57 am »
Looks good Andy!
'74 "Big Bang" Honda 750K [836].....'71 Honda 750K project.....'76 Honda 550F.....K3 Park Racer.....K5 Fiddy Dolla Special!......CB500 Fiddy Dolla Special too!!............plus plus plus.........

Offline andy750

  • Really Old Timer ...
  • *******
  • Posts: 7,520
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #291 on: July 31, 2020, 06:41:12 pm »
Looks good Andy!

Thank you! Big relief getting it back on the road. Now thinking about tires - what do you like? I always buy BT45 but feel like a change for this bike
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico (CB750K4), 2003 - European Tour (CB750K4), 2004 - SOHC Easy Rider Trip (CB750K4), 2008 - Adirondack Tour 2-up (CB750K4) , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. VStrom DL1000 2003
4. XLR650L 2006

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline Alan F.

  • just the essentials
  • Old Timer
  • ******
  • Posts: 4,243
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #292 on: July 31, 2020, 07:11:21 pm »
BT-46 is available, I haven't heard any ride reports though.
Free Fork Swaps and Upgrades info parked at http://sites.google.com/site/alansdocuments/ 

My stalled 750K3 build: http://forums.sohc4.net/index.php?topic=46082.0

Fast moving 750K8 build started 5/17/20
http://forums.sohc4.net/index.php/topic,182592.0.html

Offline RAF122S

  • I feel like a very very
  • Really Old Timer ...
  • *******
  • Posts: 7,451
  • SOHC4 member # 2605
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #293 on: July 31, 2020, 09:46:30 pm »
Someone recently mentioned putting a new BT-46 on the rear of their CB. Do not recall whom. Would a Google search find reference to BT-46?
David- back in the desert SW!

Online Kevin D

  • Occasional
  • Master
  • *****
  • Posts: 1,817
  • SE Michigan
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #294 on: August 01, 2020, 03:10:31 am »
https://grippingstories.com/articles/2019/battlax-bt46-the-new-reference-bias-touring-tyre

BT46: wet road performance improved about 10% by modification/enhancement of sipe design.
At least, that’s the Bridgestone pitch.
UM application, tube or tubeless.
71 CB750 K1
88000 mi
Original Owner

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 9,665
  • Bike almost back to the 70's 2015
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #295 on: August 01, 2020, 07:05:14 am »
Rear with longer life would be fine. Over 4000 miles with some inspired accelerations.

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 9,975
  • Big ideas....
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #296 on: August 01, 2020, 08:09:13 am »
 Happy to say the broken pilot jet has been extracted and Andy should have the carbs back very soon.
Owner of the "Million Dollar CB"

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 9,665
  • Bike almost back to the 70's 2015
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #297 on: August 01, 2020, 09:47:44 am »
Golden boy to live that close to a superb support, huge knowledge and fantastic craftsmanship!
Good friend too!

Offline andy750

  • Really Old Timer ...
  • *******
  • Posts: 7,520
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #298 on: August 01, 2020, 01:56:00 pm »
Golden boy to live that close to a superb support, huge knowledge and fantastic craftsmanship!
Good friend too!

Very well said Per and couldn’t agree more. I first met Mike about 15 years ago through the forum and it has been an honour to know him.
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico (CB750K4), 2003 - European Tour (CB750K4), 2004 - SOHC Easy Rider Trip (CB750K4), 2008 - Adirondack Tour 2-up (CB750K4) , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. VStrom DL1000 2003
4. XLR650L 2006

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline andy750

  • Really Old Timer ...
  • *******
  • Posts: 7,520
Re: Andys CB810 K2 road racer- updated 07.24.20 on the road again!
« Reply #299 on: August 01, 2020, 01:56:46 pm »
Happy to say the broken pilot jet has been extracted and Andy should have the carbs back very soon.

Thank you Mike!!!!   ;D
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico (CB750K4), 2003 - European Tour (CB750K4), 2004 - SOHC Easy Rider Trip (CB750K4), 2008 - Adirondack Tour 2-up (CB750K4) , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. VStrom DL1000 2003
4. XLR650L 2006

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

 

;
Honda