Welcome, Guest
Username: Password: Remember me
  • Page:
  • 1
  • 2

TOPIC:

Where can I buy VM22 carb idle jets? 02 Feb 2023 19:15 #879696

  • johnmull
  • johnmull's Avatar Topic Author
  • Offline
  • User
  • Posts: 33
  • Thank you received: 1
I found this reference from an older post from GD4Now.  Would it work (or be worthwhile) to remove my #50 jets?  I think my choke not be off is being caused by the restriction this #50 is making.    I can't find replacements from the originals.  My other thought is to drill them larger but that is extreme to me.

 "Regarding the #50 jet, to the best of my knowledge, that jet was stock only on the vm22ss and the vm24ss carbs that have only a pilot screw (not an air screw or those that had both). I have removed these 50 jets from several different sets of carbs, both 22s and 24s, without any running issues. Not sure just why they were used stock. Can see how it would sort of act as a pre-limiter of the volume of fuel pulled up by the pilot jet and would also increase the velocity of the fuel as it is pulled up. But as I said I have removed them with out any running issues noted on both stock air box and pod setups."

Please Log in or Create an account to join the conversation.

Where can I buy VM22 carb idle jets? 03 Feb 2023 04:12 #879707

  • Warren3200gt
  • Warren3200gt's Avatar
  • Offline
  • User
  • Posts: 1436
  • Thank you received: 648
That 50 jet was only added to help on emissions and is absolutely not required for normal operation. 
​​​​​​With the wet bowl fuel level method they should all be between 2 and 4 mm below the bowl mating surface, so 3mm on all of them is fine. 
Have you set the slide height correctly? Bench set them then vacuum sync them? 
"IF" your carbs and timing are set up correctly your engine will run iffinately better with an electronic ignition system opposed to a points/condenser system. Both the pulse length and voltage will be much more consistent with electronic giving more stable idle, better performance, ease of maintenance and fuel consumption. This is why 80's bikes all had electronic ignition. 
It's all round better. 

Going back to your carbs are they fuel screw (under the carb at the back of the fuel bowl) or airscrew ( on the side of the carb by the air intake mouth)? 
 

Z1000J2 somewhat modified!

The following user(s) said Thank You: johnmull

Please Log in or Create an account to join the conversation.

Where can I buy VM22 carb idle jets? 03 Feb 2023 10:19 #879741

  • gd4now
  • gd4now's Avatar
  • Offline
  • User
  • Denco where did you go?
  • Posts: 1245
  • Thank you received: 361
I have found it was OK to remove the #50 jet, which was stock on all the vm24 or vm22 carbs that have only a pilot screw (not an air screw or both) But you are there and I am not so do what you need to do. By the way the part number for the #50 jet is 92064-050. 

You indicate that choke is required to idle, and if you turn it off it will flood the carbs and die.  It is doing just the opposite. These carbs do not have a choke, in that there is nothing to lessen the air entering the carb throat.  Instead these carbs have an en-richer circuit which adds fuel to help with cold starts. When you push down the choke lever to turn it off you are decreasing the fuel amount that enters the carb and therefore leaning the mix of air to fuel So it is not flooded with fuel, but rather with air..
1977 KZ650 B1
Pods and Denco header


This is my Z

OLD KAW OWNERS SMILE ALOT
The following user(s) said Thank You: johnmull

Please Log in or Create an account to join the conversation.

Where can I buy VM22 carb idle jets? 03 Feb 2023 17:58 #879765

  • johnmull
  • johnmull's Avatar Topic Author
  • Offline
  • User
  • Posts: 33
  • Thank you received: 1
Super.  Thank both of you for the comments on the #50 jet.  I already have the carbs back on, but next chance I get those will get pulled.  Having the part number 92064-050 you gave me is a helpful.  My kits I find, just didn't have those provided.  I would prefer to keep this bike as stock as possible.  Replacing the #50 would be my preference but growing up in the days of silly emissions 70's, removing the jets makes sense.  I had a lot of really bad running cars in the 70's.  End of editorial comment on emissions.

Warren, Yes I am at 3mm on the clear tube tests.  The fuel/air mix screw is at 1 1/4 now.  Although my choke was on, I could get an RPM change as I changed the mix screw up to 2-3 turns out.  I put it back to 1 1/4 starting point.  My thinking is with the choke out 1/2, I am not getting a valid fuel mix adjustment on the screw.  I prefer to have it off before deciding the proper air mix.

Neil Conway from Facebook's KZ650 group suggests to run the bike a long distance with the choke 1/2 and it will allow me to close it once well run. His comment on #50 being removed": "see no reason not to pull them.   All the z650's I have done need choke for a good while dependant on temperature and will often die if you drop the choke too far so I always start and ride straight off as riding gets more heat into the cylinders more quickly."

Also thank you for correcting me on what happens when I shut off the choke.  It is not flooding the engine but closing the fuel off...more air.  Ok, good to know.I will rethink handling my problems.  Also, Neil Conway is telling me similar...to leave the choke on is fairly normal.  Makes sense to me because I am garage testing this in the winter time 20-30 degrees F.  The engine gets warm auto 200 degrees but certainly the air temperer being mixed is not Texas heat. Chicago cold.

On carb sync'ing, they have been sync using my 4 vacuum gauges.  I will redo them once a get a cleaner idle.  I am about there now.  I also use the Gunsen Color tester on each cylinder.  I have converted several bikes to Dyna S ignitions including this bike a year ago.  I just ran into problems with this one.  So electronic ignition should be (probably) is better, but for now I am back to old school points on this girl.  

Thanks again for ideas/comments and education.  John

Please Log in or Create an account to join the conversation.

Last edit: by johnmull.
  • Page:
  • 1
  • 2
Powered by Kunena Forum