TOPIC:

Sorry it took so long to get back to you guys...the first thing I did was plug the vac hole as shown in the diagram above...I then started the bike and had vacuum and was able to sync the carbs...still sounded like it was running on three cylinders...I then took a water bottle and sprayed it on the headers, one and three were drastically hotter than two and four...I cleaned the pilot jet, the pilot mixture screw of carb #4 and even sprayed carb cleaner in the pilot screw hole and watched it come out of the pilot jet hole...I then adjusted my float height and put the bowl and pod back on...I started it up and still sounds like it's running on three cylinders and when I try turning the pilot mixture screw it has no affect except for one little hiccup/blurb near fully seated.
I'm getting spark because when I spray carb cleaner in the carb it runs on all four cylinders.

but I have vacuum now...thanks so much you guys are awesome!!

Post edited by: cnyl, at: 2007/01/02 22:29

cnyl wrote:

Sorry it took so long to get back to you guys...the first thing I did was plug the vac hole as shown in the diagram above...I then started the bike and had vacuum and was able to sync the carbs...still sounded like it was running on three cylinders...I then took a water bottle and sprayed it on the headers, one and three were drastically hotter than two and four...I cleaned the pilot jet, the pilot mixture screw of carb #4 and even sprayed carb cleaner in the pilot screw hole and watched it come out of the pilot jet hole...I then adjusted my float height and put the bowl and pod back on...I started it up and still sounds like it's running on three cylinders and when I try turning the pilot mixture screw it has no affect except for one little hiccup/blurb near fully seated.
I'm getting spark because when I spray carb cleaner in the carb it runs on all four cylinders.

but I have vacuum now...thanks so much you guys are awesome!!<br><br>Post edited by: cnyl, at: 2007/01/02 22:29

Forgive my pressing a little about the pilot jet, but the symptoms still point to fuel starvation in #4 at low rpm. Are all four cylinders firing during rapid open throttle acceleration or at at higher rpm, say at 60 mph? The higher rpm should remove pilot jet condition from the equation because the fuel mixture at higher rpm then comes from interaction of the jet needle with the needle jet (not so much from the pilot jet). The cleaner spray passing from the pilot screw hole through the pilot jet hole might only prove the "air" passage is clear (depends on which pilot jet hole is being referred to -- hole lengthwise thru the pilot jet or hole in the carb body on the engine side of the throttle slide where the fuel mixture comes from when the slide is closed.)

When cleaning the pilot jets, were they removed so that daylight could be seen through the longitudinal bore and all lateral bore holes? Or were they left installed in the carb body and just sprayed through?

Have you studied the parts diagram available at www.kawasaki.com (it shows the pilot jets, etc., but does not show the hole in the bore between the engine and throttle slide)


Keep the faith.

Post edited by: Patton, at: 2007/01/03 19:17

Thanks Patton, The pilot jets were cleaned and day light can be seen through all the holes. I didn't know about other (fuel) hole though.... At higher rpm's it seems as if it's trying to run on all 4. I think your correct about the fuel starving problem. The float bowl has fuel in it though..
Do I need to pull the carbs to clean it?

Glad you got vacuum on #4 now - one problem solved. Like patton says it really does sound like the pilot jet and this kind of problem can be really frustrating if you have to take the carbs off repeatedly. Unfortunately it looks like you'll have to go through them one more time. I've had similar problems in the past and it was only when I had totally taken everything in the carb apart and not just blow through every hole but poke every hole I could find - and I found some I had'nt realised were there - with guitar string and fishing line and brush bristles did I get things running the way they should. It is amazing how the tiniest blockage in the pilot jet or one of the little airways accociated with the pilot jet can screw things up.

Having said all that I have to admit that I'm not familiar with your particular carbs but the basic idea should be the same as mine and others.
Good luck and let us know what you find.

cnyl wrote:

Thanks Patton, The pilot jets were cleaned and day light can be seen through all the holes. I didn't know about other (fuel) hole though.... At higher rpm's it seems as if it's trying to run on all 4. I think your correct about the fuel starving problem. The float bowl has fuel in it though..
Do I need to pull the carbs to clean it?

Having never attemped this, the idea may be as screwed up as a football bat, but might work since the #4 float bowl is on the outside and perhaps accessible for removal while leaving the carb bank attached to the motor. Let's say the float bowl is off and the pilot jet is reachable with the small extension tube attached to the spray can of carb cleaner. Clamp the throttle wide open so the slide will be up allowing you to see through the bore and see the small hole in the bottomside of the bore between the engine and throttle slide (this being the small outlet hole where the fuel mixture comes from at idle speed when the slide is normally down). Leave the pilot air screw screwed in. The idea is to squirt spray through the pilot jet and watch the spray come out the small hole at the bottom of the bore (to show the fuel passage is clear from the pilot jet intake to the small hole in the bore). Of course all this is much easier with the carbs removed and on the bench. Please WEAR GOGGLES when spraying. Remember, there is an air passageway (controlled by the pilot air screw) and a fuel passageway (via the pilot jet) which two passageways join together allowing a fuel/air mixture to emerge from the small hole in the bottom of the bore between the motor and throttle slide. The amount of fuel in this mixture is controlled by the pilot jet. The amount of air in the mixture is controlled by the pilot air screw. I'm assuming the air passageway is clear because opening the pilot air screw has an effect. With the pilot air screw turned all the way in, it is stopping the air supply through the air passageway which gives more effect to the inadequate fuel supply through the pilot jet due to a blocked or partially blocked pilot jet (my current theory). Might be wrong here (see football bat), but also believe a too low float level could have the same effect by prematurely preventing fuel supply for pilot jet pick-up even when the pilot jet and passageways are perfectly clean. If insufficient fuel is reaching the pilot jet (regardless of how clean the pilot jet and both passageways are) then there is no fuel in the fuel passageway to mix with the air in the air passageway to create the fuel mixture which is supposed to be available at and emerge from the hole in the carb bore between the engine and throttle slide. The fuel mixture supplied from the mentioned carb bore hole is virtually the only fuel mixture available to and used by the engine at idle speed. If fuel starvation at idle rpm is the problem, a likely reason is blockage in the pilot jet or passageway from the pilot jet to the carb bore hole which supplies mixture when the slide is down. Or maybe the float level is still too low thereby preventing sufficient fuel uptake up into the pilot jet (see football bat )

BTW, did you try spraying carb cleaner over the connection between the carb and manifold (the engine side of the carb) with the engine running. If there is a leak allowing intrusion of outside air, it will suck in the carb cleaner (or starter fluid or WD40 or propane gas) and make a noticable difference in running. If such spraying makes no difference in running, there is probably no leak in the connection. A leak here could aggravate or contribute to a too lean condition at idle and actually throughout the entire rpm range.

And please remember the goggles.

Reference posting 1980 KZ550A1 carb parts from www.kawasaki.com




Post edited by: Patton, at: 2007/01/04 15:44

Carb parts numbers and descriptions

Ref # Part # Description Qty Spec #
1 21083-1006
Add to pick list ARM,THROTTLE 4
2 92009-1079
Add to pick list SCREW,ADJUST,THROTTLE 4
3 92043-1065
Add to pick list PIN,SPRING,THROTTLE 4
4 92081-1189
Add to pick list SPRING,THROTTLE ARM 4
5 312B0500
Add to pick list NUT 5MM 4
6 92022-1167
Add to pick list WASHER,PLAIN 4
7 92009-1080
Add to pick list SCREW.CNTSNK HD,4X12 4
8 11034-1587
Add to pick list BRACKET ASSY,THROTTLE 4
9 16025-1038
Add to pick list VALVE,THROTTLE,CA2.5 4
10 16009-1060
Add to pick list JET NEEDLE,#4D92 4 USE FOR 16001-1210
10 16009-1061
Add to pick list JET NEEDLE,#4D93 4 USE FOR 16001-1285
11 92037-1157
Add to pick list CIRCLIP,JET NEEDLE 4
12 220B0312
Add to pick list SCREW PAN HEAD 3X12 12
13 461F0300
Add to pick list WASHER SPRING 3MM 12
14 16017-1044
Add to pick list NEEDLE JET,#V95 4 USE FOR 16001-1285
14-1 16017-1057
Add to pick list NEEDLE JET,#V95 4 USE FOR 16001-1210
15 92055-1069
Add to pick list "O"RING,5M/M 8
16 92063-1055
Add to pick list MAIN JET,#92 4
17 92064-1028
Add to pick list PILOT JET #32 4
18 16014-1024
Add to pick list SCREW,AIR ADJUSTING 4 USE FOR 16001-1210
18 16014-1019
Add to pick list SCREW,AIR ADJUSTING 4 USE FOR 16001-1285
19 92055-1070
Add to pick list "O" RING,AIR SCREW 4
20 92081-1190
Add to pick list SPRING,AIR SCREW 4
21 16030-1009
Add to pick list FLOAT VALVE ASSY. 4
22 11009-1160
Add to pick list GASKET,FLOAT VALVE 4
23 16031-1009
Add to pick list FLOAT 4
24 92043-1066
Add to pick list PIN 4
25 11009-1161
Add to pick list GASKET,FLOAT CHAMBER 4
26 92066-1065
Add to pick list SCREW,DRAIN 4
27 92055-1071
Add to pick list "O" RING,OVERFLOW 4
28 220B0416
Add to pick list SCREW PAN HEAD 4X16 16
29 461F0400
Add to pick list WASHER SPRING 4MM 16
30 21083-1007
Add to pick list ARM,CHOKE 4
31 16126-1024
Add to pick list VALVE ASSY,CHOKE 4
32 11009-1162
Add to pick list GASKET,MIXING CHAMBER 4
33 16005-1008
Add to pick list TOP,MIXING CHAMBER 4
34 220B0414
Add to pick list SCREW-PAN-CROS 12
35 461F0400
Add to pick list WASHER SPRING 4MM 12
36 49122-1010
Add to pick list PIPE,BLEED 4 USE FOR 16001-1210
37 92066-1051
Add to pick list PLUG,PILOT SCREW 4 USE FOR 16001-1210

Thanks guys. Fingers tired yet Patton?
This weekend i'm pulling the carbs off again and will have the wife's laptop next to me in case I forget something. Thanks for all your help!
I'll keep you posted.
It's probably something so simple... That's how it goes for me most of the time.

cnyl wrote:

Thanks guys. Fingers tired yet Patton?
This weekend i'm pulling the carbs off again and will have the wife's laptop next to me in case I forget something. Thanks for all your help!
I'll keep you posted.
It's probably something so simple... That's how it goes for me most of the time.

Not at all -- Know how frustrating this can be and glad to help (at least try to help). And especially frustrating while your fair weather gods are still smiling. Suggest performing the quickie "spray onto manifold while idling" test before pulling carbs.

Still rooting for you.

I had your exact same problem and you will find it somewhere buried in this forum. Simply run a small "e"
guitar string through the pilot jet. Hey it fixed my problem and I could see daylight before I did it.

A hair dryer works good to warm up the boots to install the carbs easier. A heat gun can burn them.

Remove and replace carbs the easy way.

Amazing how hard and brittle the carb boots become over the years, and crack and chip on removal. Takes about seven minutes to remove and set the carb bank on the bench which includes removing the fuel tank and maneuvering around oil cooler hoses. A little longer to reinstall, but not unpleasent absent hassle with "hard as rock" boots. New boots from Z1E are "inner tube" soft and pliable and simple to install -- just apply some silicone and twist them into the appropriate airbox holes. Also nice having an extra long phillips to reach and loosen the inside clamp screws on the manifold mounts. Completely unscrew the rear clamps and carefully spread them enough to remove thereby avoiding interference with loosening the rear boots (the clamps bend open easily for removal and close together easily when later reinstalled). Okay to employ a wooden dowel, 1x2 or non-metallic whatever to carefully lever the carb bank from the manifold (after clamps loosened and boots disconnected). Also don't forget to disconnect the throttle cable ends from the carbs -- easiest to re-connect just before re-inserting carb bank into the manifolds (spray with Armoral if desired). May install the inside boot clamps with screws on top facing the outside for easier access, and the outside boot clamp screws on the bottom per stock configuration.

While carbs removed, suggest placing a towel over the manifolds to protect from insects, etc., until reinstallation of the carb bank.

Here's the Z1E link if interested in new boots:
www.z1enterprises.com/detail.aspx?ID=331