Also Check Out

© 2014 Message Forums
June 25, 2019, 12:31:20 PM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
News: Welcome to! Please register in the Forum to post messages or view attached photos.
  Home Help Search Login Register  
  Show Posts
Pages: [1] 2
1  General Category / Tech Corner / Carb needles on: December 05, 2018, 07:40:41 PM
The CB-1 from Heck article mentions switching out the stock J57A needles which are 2.51 diameter to thinner (richer) needles at 2.49mm diameter. Has anyone on the list ever sourced these thinner needles? Sudco is in the dark! Using an exhaust gas analyzer it is clear that the mid-range needs more fuel. Shimming the needles is proving less successful than using the correct needles.
2  General Category / Tech Corner / Re: Starter clutch death rattle on: June 06, 2017, 01:50:28 PM
Thanks VH.  I scrolled back a few years and a guy from Wisconsin added that a failing starter solenoid can also lead to starter issues. The solenoid will chatter and the starter sees intermittent current and voltage.  $12 bucks for a new generic replacement. Seems reasonable given the age of the bike.  And if I read you correctly the main clutch is also prone to rivet loosening? Please confirm.  Laf
3  General Category / Tech Corner / Starter clutch death rattle on: June 05, 2017, 09:41:38 PM
This forum pointed the way to my discovering the three rivets that hold the starter clutch together starting to loosen up.  The at idle, death rattle, was the first clue. Failing to crank over the engine yesterday was the second clue. I removed the starter clutch leaving the gear wheel in place but removing the caged roller bearing.  I cleaned everything thoroughly with acetone, per my welders advice, and he will now TIG weld the rivet heads securely to the clutch body.  Have others on the Forum followed this path to save the starter clutch? Honda no longer supports the clutch as far as I can tell. There are a few used on eBay but they probably have loose rivets already. What is the Forum experience?  regards,  Laf
4  General Category / Tech Corner / Re: CR Flatslide jetting on: May 31, 2017, 03:25:11 PM
I got my replacement coils from, search for part number 30570-M68-KT7-023.
I remounted mine much nearer the front of the bike to allow for shorter leads and to provide better cooling.  Caltric sells them for under $30/pair.  Email me directly at and I will send a picture of my mounting system.  Laf
5  General Category / Tech Corner / Re: CR Flatslide jetting on: May 29, 2017, 08:43:25 PM
Fellows I finally unraveled the mystery of my poorly running CB1. The PO had removed the coils. They were encrusted with rat evidence from sitting in the barn for decades. I ohm them out as 3 ohm coils. Confirmed by the manual.  I ordered generic replacements from Dynatek. Their mini 3 ohm versions.  Well it turns out that the  Dyna coils, altho 3 ohm, will not work with the Honda  ECM. New wires, new caps, new plugs and it stills fouls plugs. Using the OEM part number I crossed referenced with  aftermarket coil manufacturers on eBay and located a perfect crossover. A new pair for $30 compared to the Dyna's at nearly $150/pr. Bike fired up and runs great.  Lesson learned. Not all 3 ohm coils are the same or interchangeable.  Laf
6  General Category / Tech Corner / Re: plug fouling #4 on: May 19, 2016, 09:51:41 PM
Thanks for the offer to look for a spare. Another CB1'er in Ohio has one in the mail to me. It should arrive tomorrow Friday on on Saturday.  I hope this does the trick.  I'll post my results.  Laf

7  General Category / Tech Corner / plug fouling #4 on: May 11, 2016, 02:53:42 PM
My CB! fouls the #4 plug. It is not about compression, or spark or clogged air correction circuits within the carb. I suspect that it has the wrong choke plunger in #4 carb. If it doesn't seat properly the choke is always on. It was unique and is not interchangeable with carbs 1,2,3. It is no longer available from Honda.  Can anyone on the forum spare a known correct #4 choke so I can test my theory.  Thanks,  Laf Young
8  General Category / General Motorcycle Discussion / Re: CB1 carb parts needed on: March 12, 2016, 03:37:48 PM
I have emailed Allen's.  I will let the group know if they can help.
9  General Category / General Motorcycle Discussion / CB1 carb parts needed on: March 09, 2016, 12:41:39 PM
I bought a set of used carbs thru eBay. Two of the carbs are missing the low speed mixture screws and springs. Honda no longer supports these parts. Does anyone on the forum have spares?  I also will need two low speed jets #35.  Thanks
10  Classifieds / For Sale / Re: CB-1 spares. Liverpool on: November 02, 2015, 09:29:35 PM
Phil; Are the carbs available and the airbox too?
11  Classifieds / For Sale / Re: Quite a few spares! on: November 02, 2015, 09:27:03 PM
Do you still have the carbs and airbox?
12  General Category / Tech Corner / Re: CR Flatslide jetting on: January 09, 2015, 07:31:06 PM
My saga continues. With the flat slide properly jetted the bike still barely runs. A compression test and a leak down test reveal no worn or leaking valves or rings. The cams are timed perfectly. There is always a fat spark at each plug.  However I suspect that the spark maybe random and not timed to the actual TDC event. The bike came as a basket case. It has two ignition modules.  Both could be bad!  Would a fellow believer in the CB-1 be willing to test each of my modules on a known well running CB-1 to determine if either of my modules is okay.  I will pay the postage in both directions. With the seat removed and the rear plastic seat surround removed the module is easily accessible. A plug & play swap that would only take a few minutes.  It would be easiest to conduct this activity with someone from the USA or Canada.  I am located in Hawaii.  Thanks for helping me get this baby off of the bike rack!
Laf Young
13  General Category / Tech Corner / Re: CR Flatslide jetting on: December 13, 2014, 02:04:39 PM
After re-reading the article on the CB-1 from Heck and reading everyones responses I elected to invest in a few OEM Keihin jets to try and bring the Flatslide CR's into some sort of beginning point to prevent the gross flooding that is presently occurring. Per the collective advice I am replacing the slojets with 38's (from 50's) and the mains at 115 from the present 130's. The parts should arrive on Monday so I hope to report soon that the bike is getting closer to rideable.  The NC-23 cams won't arrive until after Christmas so I hope to get it dialed in first and then adjust it again if the cams upset the mixture too much.  The saga continues.  LAF
14  General Category / Tech Corner / Re: CR Flatslide jetting on: December 11, 2014, 11:15:44 PM
Gents:  Thanks for all of the input and links to the past. Sudco was of little help. The flatslide CR's were probably assemble by Ontario Moto Tech before they sold out to Sudco.  Here is how you can help.   Can anyone provide the jetting values for the entire carb circuit with stock CB-1 carbs. My OEM service manual only refers to them as VG06 carbs. No jet numbers are supplied.  And it is of most importance; are the stock carbs by Keihin or Mikuni?  And just for fun I purchase, below the ebay listed price, the NC-23 cam set that was recently spotted by one of you. I expect to see them by Christmas.  I am my own Santa!   Laf
15  General Category / Tech Corner / Re: CR Flatslide jetting on: December 07, 2014, 06:54:32 PM
Thanks fellows for the responses. How does one access "The CB-1 from Heck" article? Is it part of the sites archives?
After this posting I will make another attempt at finding a part number on the needle jet and I will try to remove a needle to get a part number. Armed with the additional info I will call Sudco tomorrow and see if they can unravel what I have against what I need.
The only CR flatslide package that they still offer is for the Honda CBR600F2. Perhaps I will gain some insight if they will reveal the jetting package used for this model.

Here is the history of the bike. It was purchased new in Honolulu, Hawaii in 1990. The last known registration was in Honolulu in 1998. At that time it had 13,990 miles on the speedo. The modifications at the time included a 4 into 1 Kerker racing exhaust and the four downdraft CR Flatslide carbs.  It was stored and resold as a non-runner several times over the ensuing decades. It ended up here on Maui about 3 years ago. It changed hands again and the new owner removed the head to have a look. He then decided he was in over his head and offered me the bike for $275.00.

I removed the cylinder and carefully cleaned and made sure the rings were all free. I gave the bore a light hone and stated the reassembly with new gaskets. I gave each valve and seat a clean lapping and continued the reassembly. I verified the thermostat was functioning, replaced a few hoses and dismantled the water pump to remove the decades of congealed crude. I added fresh coolant, oil and oil filter. I replaced the fuel filter and cleaned out the gas tank. I quickly discovered that two of the plug caps failed the resistance test. I sourced replacements from a modern Honda 919.

The airbox was removed long ago to fit the CR carbs. Blue velocity stacks, no air cleaner(s). Easy to spray ether starting fluid.
But first I went through the carbs with new needle and seats and other rubber bits that are exclusive to the CR type carbs. After a bit more sorting it started up but was rich. The new plugs fouled in short order. Everything was too rich across the board.  I suspect that the bike was put away those many years ago because the carbs were never jetted for a 400cc engine. I'll post the results of the Sudco conversation tomorrow.  Laf
Pages: [1] 2
Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!