Topic: Kawasaki DOHC 4 won't run on all four!!! >:(

[KB02]

I posted this on another forum as well, but thought I would pick some brains over here as well. Thanks all!!
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Okay, here's the story:
1980 KZ550C. I have been working on it and trying to get it going. So far I have gotten it to run run well on Cylnders #1-3, but it just won't run on #4.

Here's what I know:
The carbs have been cleaned and rebuilt and bench synced. (A few times now)
The valve adjustments are spot on for intake and a little tight on the exhaust. (The PO had the exhaust clearance on # 4 set at 0, it is now at .040 - clymers AND the local Kawi dealer say spec is between .060 and .10)
There is suficient spark.
The spark plugs are new.
the timing is spot on.
The exhaust pipe is clear (I was running out of things to check).
There is plenty of fuel flow to the carb, the float height is a little high, but within an exceptable range.
Compression is good on all four cylders as well.

When I squirt gas straight into the back of the carb on 4, the bike picks up and runs better but quickly dies back down again. I have a steep driveway, and when I am taking it out of the garage, when I get about half way down the driveway, #4 kicks in and runs strong for a couple of seconds and dies again. When trying to take it down the road, at about half to full throttle, it tends to kick in and run choppy, but on all four, anything less and it dies.

I have tried everything that I can think of to get this bike to run and have come up empty. The only other thing I can think of to mention is that with the air filters off, I can hold my hand over the back of the carb (Choking it out) and with the gas build up it does start to run on #4. BUT, I feel very little suction as compared to the other three carbs. Would this be a clue that might lead me in the right direction on this?
I know it has to be a fuel issue, and the local shop agrees, but I have checkd everything that I cam think of and it still isn't right.

Please help!! I am at my whitt's end on this one. Thanks, all!!

[heffay]

consider it a blessing and save gas... no seriously. 

 

when my "mystery cylinders" kick in it makes it sound so much growlier, i don't mind. 

[cb650]

Sounds like a float.



           Terry

[Jay B]

[ The only other thing I can think of to mention is that with the air filters off, I can hold my hand over the back of the carb (Choking it out) and with the gas build up it does start to run on #4. BUT, I feel very little suction as compared to the other three carbs.

It sounds like maybe you have a big air leak somewhere if you are getting much less suction from that carb. Check the rubber manifold and make sure the plug for the vacuum port is in place. I don't know the 550, but my son's 750 has CV carbs. Make sure the diaphram isn't leaking. I think you are loosing vacuum someplace. When you go down your driveway it sounds like you are getting some fuel slopping in there and that cylinder is kicking in. Assuming of course that the jets are all clean. HTH

[cb650]

Keep me informed as I might be cleaning some 650 kawi carbs this week-end.



           Terry

[byidesign]

       Did you compression check cylnders? all check out good? is#4 way low?
You said you can hold your hand on the back of the carbs?{no air filters/box attached?}
         carbs not way out of sync...?{like #4 throttle plate more closed than the other three?}
     Not being that familiar with it, I will dare to think these are the
     CV type carbs, and you checked the slide pistons are working freely, and
       if they are the rubber diaphram type, that there are no
        cracks or tears in the diaphram?
             Jets/floats all clean and OK..
         Some of these machines are very picky about removing air cleaners,/exhaust changes
             and will upset the balance of carbs by removing things without rejetting...
                if a slight restriction {hand over the intake} straightens it out..{everything else
               checking out good}that might be your case...
                      as the airbox/filter, provides a certian constant intake restriction.....
                        hope it helps
                               Bruce
                           
               

[KB02]

Sounds like a float.
           Terry

Float is good and if anything a little high. That was the local shop's idea as well.

From all the suggetions that I hav gotten from here and the other forum that I posted this in, I thinking it muct be a vacume leak somewhere. As I said, compression is good, carbs are cleaned and bench synced, valve are all set right... It must be a vacume leak somewhere.

Thanks, Guys!!!

[dusterdude]

can u pick up the carb slide with your fingers and if so does that make it run better?

[heffay]

  holy moley duster!  you've got a lot of posts!   

[quietlikeachurch]

Just look at Bob Wessner...I think he's about 20 posts away from 3 grand!

[Terry in Australia]

Pilot jet blocked? The symptoms are almost "textbook", but the lack of "suck" worries me, are you sure the compression is fine in that cylinder? I take it that they're not CV carbs, as you can't "Bench Synch" 'em like you can slide carbs.

If they are CV's, they don't like being run with the airbox disconnected, makes 'em run waaaay too lean........... Cheers, Terry. 

[KB02]

Nope, pilot jet is clean. That was my first though, too actually. While Cynder's 2&3 were a little blocked that last time I cleaned them out, theu are the two cylinders that are running the best.

After some further inspection, I have found that on of the vacume lines running out of the Carb boot is loose. I'm going to have to pull the carbs and inspect those boots a little bit further. I think that may be my problem. I'll let you guys know.

[Super Sport 550]

I take it that they're not CV carbs, as you can't "Bench Synch" 'em like you can slide carbs.

Sure you can. You just flip the carbs over so that the slides fall down and shine a bright light in through the other side. Then set up all the throttle valves so that you can't see light through the bottom of any of them when the throttle is all the way closed (you will have to back the idle all the way down to do this).

At least, that is the method I have had the best luck with...

I'm sure a KZ550 has CV carbs anyway.

[crazypj]

KZ550 has shim under bucket valve adjustmend (which rarely gets done as it means taking the cams out) The valve clearances are real wide (about 0.012" ex) but valves still get burned sometimes. High float level means low fuel level. I think there is a fuel height measurement for this bike so you dont have to take carbs off.
PJ

[KB02]

I've been using the old trick of connecting a clear tube up to the drain nipple  and holing it up next to the carb body. It was perfectly fine untill I messed with it after the local shop thought that could be an issue. I'll probably reset it back to stock once I get all the vacume leaks figured out.

And, actually, the intake valve clearance is .040 to .080. The intake is sitting at .060. Still possibly a burnt out valve, but I will save that nightmare untill after the vacume stuff is ruled out. 

[crazypj]

I have  Genuine Kawasaki manual for KZ500B-1 which covers all models to D-1(1981)
Fuel height is 3.5mm from edge of carb body.
You will not find a float height measurement , but its 22.5mm (I did a lot of work on these, long time ago)
Valve clearance is 0.004"~0.006" inlet (0.10~0.20mm) 0.040 is forty thou
Exhaust is 0.15~0.25mm (0.006"~0.010") ( should have looked it up first )
If you need any specs PM me.
PJ

[KB02]

Valve clearance is 0.004"~0.006" inlet (0.10~0.20mm) 0.040 is forty thou
Exhaust is 0.15~0.25mm (0.006"~0.010") ( should have looked it up first )

Oops... Sorry. That's what I meant to type.

Having a yard sale AND working this weekend, so I havn't had too much time to tinker on in, but I have a little. I'm convinved more than ever now that it's a vacume leak.

[Terry in Australia]

What's a "tard" sale mate, is that legal? 

[Jay B]

PM me the next time you have a tard sale will ya? I've got a dog I'd like to put on it.

[KB02]

Ever have one of those day where you really hate the fact that over the years you have spilled more crumbs and liquids on your keyboard than on your shirt? And then the keys don't work as well? And then you have to make up excuses for poor grammer and typing skills?   

(and then you have to go back and edit your posts...)

[dusterdude]

  holy moley duster!  you've got a lot of posts!   

yea i like to see myself in print.

[crazypj]

Ever have one of those day where you really hate the fact that over the years you have spilled more crumbs and liquids on your keyboard than on your shirt? And then the keys don't work as well? And then you have to make up excuses for poor grammer and typing skills?   

(and then you have to go back and edit your posts...)

I'm so glad I'm not the only one who does this
PJ

[Jay B]

So did you ever get the Kaw going? Vacuum leak?

[KB02]

Well, lack of time and money have kept proper performance at bay for the meantime. I was abkle to work with it a little bit with all the vacume lines blocked off and it ran much better. #4 still doesn't want to fire at idle, but I think that just has to do with some adjustments.

It runs better. As soon as I get it up into the mid to high RPM's, she starts to break up a little (okay, allot). Plus I've got to get a new exhaust for it, too.

Lots and lots of little things........

[cb650]

Anyone know what the mixture screws are set at on a 84 550.  It has cv's and my manuall doesnt give this.  Says count before removing and they where all over the place.  Someone did a #$%*ty job before.




                                           Terry