Doctor Jack
Novice Class
Posts: 31
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posted August 29, 2002 11:10 PM
 Edited By: Doctor Jack on 30 Aug 2002 00:15
Air bleed screws and why?
How come I cant find anything on the procedure to set the air bleed screw. Its not even in the factory manual. I realize this is a very tricky procedure because its an air bypass adjustment and if you turn one of them then it will change the synconisation then you will have to adjust the the sync screws to get it back synced. Does anyone know what Im talking about. They are the screws that are blocked off with plugs like a mixture screw on a carb.
What are thier purpose anyway. You can close them off (Witch most times are from the factory or close to it) then ajust the idle and sync the carbs. If you set the screws at two turns out it will raise the Idle so then you will have to back off the idle screw to get the correct idle speed again and recheck the sync. The only diferance I can see is it will change the Throttle positioning senser voltage because of the idle having to be lowered by the buterflys idle screw to get the correct idle speed. Can any experts clear this up for me. I would love to here from the experts on this.........
  
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VincentHill
Needs a life
Posts: 6520
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posted August 30, 2002 04:19 AM
Doug Meyer wrote on this! The air Bleed Cannot change the Sync of the Throttle Bodies because that is a Mechanical adjustment of the butterflys! The Air Bypass screws are under the small (about 3/8th") Vertical cylinders that are plugged on each throttle body. The manual "Mentions" Do not turn them too much!! I think this adjustment is sort of like the Pilot air screws adjustment on carburators! My feeling is that Idle and off idle is the main control! I plan to "Remove the Plugs" and "Play" with mine to see if I can smooth the idle and off idle! Doug sets his a certain number of turns! ??? 2 out I think??
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psycho1122
Pro
Posts: 1608
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posted August 30, 2002 05:59 AM
2 out w/ a pipe will do wonders for your off idle/closed throttle response!!
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You say PSYCHO like it's a BAD thing!!
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psycho1122
Pro
Posts: 1608
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posted August 30, 2002 06:00 AM
2 out w/ a pipe will do wonders for your off idle/closed throttle response!!
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You say PSYCHO like it's a BAD thing!!
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Zx23rr
Expert Class
Mahogany Bomber Pilot
Posts: 242
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posted August 30, 2002 07:31 AM
Zx23rr
I would hazard to guess that if you set your throttle plates the same, and then balance them with the air screws(using a mercury vacuum stick), it will probably smooth out the idle.
Now I know what I will do next when I get some free time-ya, right!
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Doctor Jack
Novice Class
Posts: 31
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posted August 30, 2002 08:50 AM
Your wrong about it not changing the sync. I know the sync screws are a mechanical adjustments to the butterflys. But you need to under stand that syncronizing works off of vacuum. and when you turn the air bleed screws it will change the vacuum, Which will throw the sync off. If you dont beleave me......Put your gauges on and turn one of the air bleed screws out a turn or so......you will see it change the sync. I did it. You need to relize that turning the air bleed screw out is basicaly the same thing as opening that butterfly. I think Im going to close all the screws, Then sync the butterflys, Then check idle and of idle....If its not satisfactory then I will turn the bleed screws out one turn, Then reset the idle, then check the sync, It should be ok because I turned them all the same amount, But If its off a little then I will use the air bleed screws to fine tune the sync, because I know the butterflys are synced from the first step. I dont mean to sound harsh but everyone needs to understand that the air bleed screw is basically a ajustable vacuum leak and adjusting it will change the vacuum. If the vacuum changes....It will throw the sync off even if the butterflys are pefecally mecanicaly synced because you are creating a vacuum leak and you use vacumm to sync the butterflys. I see where people can really make a mess if thier played with......Thats why I like my Idea of closing them off to set the butterflys sync. That way I know they are all mecanicaly the same.
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VincentHill
Needs a life
Posts: 6520
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posted August 30, 2002 09:05 AM
Edited By: VincentHill on 30 Aug 2002 10:10
Dr. J, why ask if you know?? If the blades are in sync and the air bleed is correct(set the same on each one), you should be in sync?? Vacum wise! Out of sync mechanical wise! Some bikes run a little rich off Idle, the more air bleed the leaner this will be! With them all adjusted the same, they should all draw the same amount of air! I did not think of adjusting them to different settings to make the idle less smooth then off set this by using the sync screws for the plates! Like I said again, Doug Meyer has some experience with them and came up with 2 turns out! Anyone can experiment and set them anywhere they want! Why not put the bike on a dyno and see the power at idle "No turns, 1 turn and 2 turns" to see if the power output is different along with any smoothness difference! I would like to know??
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Doctor Jack
Novice Class
Posts: 31
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posted August 30, 2002 09:52 AM
I dont have a dyno ....Yet
I just finished putting a 1270 kit in for a customer he has a pc3r and a muzzy pipe. So I put dougs map in and I cant get it any lower than 1250 rpm or it will start bobing for idle. I know I can do some playing with the map, But While I had the trottle bodys off.....I went a head and drilled the plugs. and I noticed that #1 was 1/8 turn out #2 was closed,#3 was closed,#4 was 1/4 turn out. I left them where they were and checked the sync. It was dead on. with no adjustments. I was mainly posting to see if anyone had a standard set point for the airbleed. But if you really think about it all..........Basically you are doing is fine tuning the Throttle posioning sensor. Heres why.........
If you close them all off and ajust the idle to 1000 rpm and the sync is set. ....Now open all the bleed screws 2 turns out. The idle will go up because basically you are giving it some air and the air preasure switch takes care of the fuel. So now you idle the motor back down to 1000rpm.........The throttle positioning sensor just changed of because you idled it back to 1000rpm. I relize this is a very small change but wanted to know why they dont talk about it in the book. They just say If thier messed with it can change the voltage onthe trottle position sensor. I can see how, But why dont they give a procedure.
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VincentHill
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Posts: 6520
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posted August 30, 2002 11:26 AM
Edited By: VincentHill on 30 Aug 2002 12:28
I think you have talked and communicated! I have yet to see a "Kawasaki" where the Pilot screws or the chain adjustor was ever correct! It is the "Order" of business I would conduct to see if I can get it correct! (BTW, Mine idles at right about 1,150 to 1,200 for a smooth idle)
First, I would set the screws (I would use 2 turns, you use anything you want, but set them all the same! Then I would set the plates, then I would turn the idle down to 1,000 "Looking at it through the power commander" (The tack is off about 200 rpms "More than what it shows")! Then set the TPS at 1.086 DC Volts, then adjust the main idle screw for the best running position! I have yet to see one that idles perfectly at a real 1,000 rpms! Even stock!
Of course the idle goes up with opening the screw adjustment because the leaner mixture makes more power which raises the rpms Of course the higher the rpm, the higner the reading from the TPS!! To get mine close to right, it was a back & forth deal with the sync screws and the main idle adjustment, then resetting the TPS When finished! When I was real careful with the RPM's and the TPS, my On-Off-On surge at 5,700 rpms left. If your customer is so fussy that the bike must idle perfect "AT" 1,000 rpms, you got a real problem! (Which can be resolved with short duration cams, low compression and high back pressure! Everything a Kawasaki is "NOT"!!
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frEEk
Administrator
ummm... yeah
Posts: 9660
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posted August 30, 2002 11:41 AM
interesting thread. wish i understood more than half of it!
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kawachan
Pro
Posts: 1031
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posted August 31, 2002 06:50 AM
I'm very interested too!! Dr. J is working on mine next week. VH, I couldn't find that article Doug M posted about the air bleed screws. It was pretty late when we (he, that is) finished the 1270 the other night. I searched over on Easy's site, too.
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RED NINJAS RULE!!
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VincentHill
Needs a life
Posts: 6520
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posted August 31, 2002 10:53 AM
It may be gone, but I will take a look for it! We were talking about his bike he ran at Bonneville
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VincentHill
Needs a life
Posts: 6520
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posted August 31, 2002 11:10 AM
quote:
It may be gone, but I will take a look for it! We were talking about his bike he ran at Bonneville
I also looked! I had a feeling that this was right after Bonneville last year and the Labusas Board had problems which means everything prior to the end of December 01 is lost in space!
He did not say much more than the fact that he was using 2 turns out and something about the effect they had! He looks in here, He would comment "Again" and we save it forever on paper in my service manual!
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Doctor Jack
Novice Class
Posts: 31
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posted August 31, 2002 10:46 PM
Well I just thought I would post my results. I closed all the bleed screws, Set the idle, And synced the bodys. I then set the screws at one turn out and reset the idle. The sync stayed set since I was very carfull to set them exactly the same. I then tryed it at two turns out. Thier really wasnt much diferance between the diferant settings, But it seemed a tad smoother at one turn out. I figuar it was because the throtal position sensor was at its best position for the amount of vacuum. People need to understand that turning the screws out does not lean it out. If you turn the screws out......That just made a vacuum change and the preaure sensor will adjust the fuel for it, But By turning the screws out the motor idles up so you have to idle it back down so you end up with the same amount of vacuum as you did before turning the screws out. So thier for the preasure switch will have the same vacuum on it as it did. The only thing that it diferant is the voltage off the trottle position sensor. So if any leaning up has acured from turning the screws out.......Its because the Trottle posion sensor voltage.........Anyways......I finished the bike. Let kawachan ride it and he liked it.....By the way kawachan....Customer left with a shit eating grin.
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VincentHill
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posted September 01, 2002 09:50 AM
Edited By: VincentHill on 1 Sep 2002 10:55
I understand what you said except I need to see what the TPS voltage difference ends up at 1,000 rpms "AFTER" the adjustments! (If there is a difference) I also need to take the bike for a short ride and check off idle and low rpm response (Read up to 3,000 rpms)! Just for grinns, I am going to take my tool to the Dyno and see (Without any other adjustments) what the sniffer shows and if there is any HP difference!)
One thing for sure in my mind is that having them all the same must work better than everyone in a different position, which may be the cause od most 12's having a bad idle / iratic idle! Whith your careful observations, I now have 2 choices to try (1 & 2 turns out!!) (do not know the code for thumbs up! Just looked and there are none 
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Doctor Jack
Novice Class
Posts: 31
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posted September 01, 2002 08:54 PM
Post your results when your done. Ide like to hear how yours turns out.....
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VincentHill
Needs a life
Posts: 6520
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posted September 02, 2002 07:06 AM
quote:
Post your results when your done. Ide like to hear how yours turns out.....
 Good play with the words  One thing is I plan to be at Matxon! That is the real world place and I may have time there to see!
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Made History @ Daytona and still one fast old man!!
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