TOPIC:

Hey all, I have purchased new ignition coils for my 1981 KZ550 C2 LTD. The primary resistance on the new coils is 4ohms and the secondary is 16k ohms.However the only cap plugs I can find locally are 5k resistance. With the caps installed on the ignition wires it increases the secondary winding resistance to 26k ohm. According to the Kawasaki factory service manual it should be 10k to 16 k ohms.I'm using new NGK D8EA plugs Is this acceptable?Thanks!

The secondary resistance value is not critical.

But the primary side is pretty important for getting proper dwell.  The 1981 Kz550 should have had 2.6 ohm coils, not 4 ohm coils.  The electronic ignition has shorter dwell so needs "faster" coils, which are usually lower-resistance coils.  Ebay and Amazon sell coils within the 2.3 to 2.8 ohm range, which is what should go with the factory electronic ignition.

4 ohm coils will probably work, but if you find the engine stutters or stops firing at higher RPMs and higher loads (during hard acceleration) you may want to look into lower resistance coils.

=11pxA bit or history for the bike.
=11pxI bought it 3 months ago from someone who couldn't get it running.

=11pxI disassembled sonic cleaned and rebuild the carbs. Installed some missing choke flaps and set the carbs according to the manual.
=11pxInstalled a factory air box with all new airbox boots.
=11pxNew plugs, new gas with inline filter.
=11pxChecked the timing under the valve cover, made sure the adjuster wasnt seized.
=11pxNew starter.
=11pxNew battery,

=11pxI was finally able to get it running but it is very difficult to start the first start of the day. Takes about 20 minutes of cranking before it will idle. I let it warm up for a good while but when I give it throttle it bogs down and dies.

=11pxThe factory coils that came with it are 2 ohm on the primary. One coil had 25kohm on secondary however the other coil had infinite resistance on the secondary. According to the manual they should be 4 ohms on the primary and 16k ohms on the secondary so I figured bad coils were causing this issue.

=11pxI ordered the 4 ohm coils from Ebay because thats the specs from the factory service manual. It took 2 months for them to get to me in canada. I really don't want to order another set and completely miss the riding season.

=11pxI just got the coils yesterday and haven't had a chance to try them in the bike. Will be doing that today but I'm honestly not expecting this bike to run. It's been fighting against me every chance it can.

=11pxWill update.

You have to read the supplement for 1981.  The 1979 and 1980 models had points which use 4 ohm coils.  Your 81 should have an electronic igniter.

If you follow the links in my signature, you can download several FSM's which include supplements for your bike, and there are other supplements for later models.  I recommend you download all of them.

Before you open the valve cover you should read the warning in my signature.

Also if you follow the links, there is a website with details about your TK22 carbs.  It includes a mod for the fast-idle feature which comes into play during startup.  Playing with that can sometimes make startup easier.  But it sounds like there may be more serious issues going on.

After you get it started, you should get a spray bottle with water and spray the header pipes.  The water will dance off the running cylinders, and will slowly run and boil off of the non-running cylinders.

I read about the tensioner warning before I removed the timing cover.

I tried it with the new coils and no change.
I am at the point where I dont know what else it could be.
It's been 3 months of trying things and waiting for parts and I'm all out of ideas. I may have to just bite the bullet and take it in to a shop.

Have you taken any photos we could look at.  Sometimes something will show up in a photo that hasn't been considered.

Have you tried starting fluid (ether) to aid startup?  It makes it a lot easier on the starter motor until you get the bike to start properly on its own.

Once started, try the water trick on the exhaust.  It will at least tell you which cylinders are having problems.

Also, are you sure the plug wires are going to the correct plugs? And have you checked for sparks on all four plugs?  If not, ask, and we will give instructions on how to check properly without doing damage.

 

I've done water bottle trick and all four cylinders are firing.
One noticed one wiring diagram that show 1 and 4 should be the green wire but I've seen another diagram that shows the green should be 2 and 3. I've tried swapping them and it wont start at all the other way.

I've checked spark one at a time by removing and grounding against the case. I have spark and like I said all 4 cylinders are firing.

I can upload some pics but not sure how much it'll help.
Can take some better ones this weekend

I really appreciate the help
 

What type of fuel filter are you using. It must be gravity type like a lawnmower would have. Have you set fuel float levels. Is the petcock working? You could try and auxiliary fuel supply without the filter to test. You could buy a fancy aux tank but an old (but clean) lawnmower tank works great. 

Thanks for the photos.  Great looking bike, by the way.

The cam timing looks good to me.

Do you have the vents and hoses hooked up like the first page of the Tk22 website shows?
And, again, you may want to play with the fast idle adjustment if you think that has been changed.

The 550 (and all inline-four Kz's, actually) originally came with the black wire controlling the coil for cylinders 1 & 4, and the green wire controlling the cylinders for 2 & 3.  But if someone flips the timing rotor 180 degrees, then the wires will fire the opposite pair of coils.

As a side note, on the smaller motors, the coil with the black wire is mounted on the right side, whereas on the big motors (900 and up) it's mounted on the left side.  It's good to keep things in the stock location (and the rotor in the correct orientation) to make troubleshooting less confusing.

There is a point on the timing rotor.  It should be pointing toward the "TEC" logo on the advancer unit.  It'll take a flashlight etc to get a look at the advancer unit.  You should check the ignition timing advancer anyway.  If it's stuck advanced, that'll make starting difficult.  And if it's stuck retarded, it will only get up to a certain RPM and bog.  You want to make sure it's free and able to snap back easily and both springs are intact.  Also there are tiny rubber cushions on the arms that sometimes fall off and alter timing a bit.

But if the water is dancing off all four pipes it sounds like it is firing fully at idle.

Since it was maybe missing the airbox, maybe someone drilled out the jets, or replaced the jets?  Like Ed said in your carb post, exhaust changes alone won't require major jetting changes.  But if someone had pods before, they may have made some changes.  A Tiny drill bit kit or wire gauge set is useful for measuring your jets to confirm the size actually matches what is stamped on the jet.

Is the exhaust very loud?  Some really loud exhausts may need a bump in the main jet or pilot jet but not that much, and it usually won't stop it from being rideable.

How many turns out are the airscrews set at?

Normally, if someone put in bigger jets, that would make it easier to start.  And cold starts in summer should be easier in general.

I know you don't want to take those carbs off with that airbox in place, so will try to suggest anything short of opening the carbs again.

Does it bog more with choke on (lever up) or choke off (lever down)?
The choke plates can be removed while the carbs are still mounted in case there is a chance one is stuck open.

Another thing you can try when starting, is cover the airbox opening while cranking.  That'll be a definitive choke and will pull up extra fuel.  It's an oldtimer trick for starting motors.  You have to get the feel of when to remove the blockage as the bike starts to fire...good skill to have.


 

I measured the float height when rebuilding the carbs and I've also done the clear tube level trick.
I set the carb up according to the FSM

I removed and cleaned the petcock. It seems to pull fuel when on prim.

I checked to make sure the timing advancer was not stuck. I removed it and cleaned it.
Air screws are 1 and 1/4. I've tried opening them all and closing them all but half then one full turn and no change.

The bike runs a bit better. It starts a lot easier now
Today i drilled out the original #92 main jets to a #101.6, and removed the inline fuel filter.
However If I slowly increase the throttle I can get past the bogging down and to a point where I can get the =11pxrpms up. However at idle if I quickly give it throttle it will bog and die.
Would I need to upsized the secondary jets as well?

I can pull the aftermarket gravity tank from my DR650 and use to test.

I believe this is a pic I took of the advancer when at TDC #1

I really appreciate everyone's help and input!

I'd try shimming the needles. If they are already shimmed, shim them more. I had a simular bog in my KZ305. I reshimmed 3 or 4 times, each time adding a little more shim, until the bog was gone.

I see the pickups have been unbolted from the timing plate.  The magnet orientation is important.  This page will show how to get the magnets installed correctly.
s3.amazonaws.com/gpzweb/Ignition/PickupA.../PickupAndRotor.html

If you have to roll the throttle slowly to get past a bog, that usually indicates it's too rich at the point of the bog.

Are you still using the original factory throttle needles?  Some counterfeit ones look almost identical, but they are slightly too skinny and end up way too rich.  The area of concern would be the early part of the throttle rotation. That is where the pilot jets and needle position matter most.  The main jets will only slightly affect that range.

Once you get to full throttle does it run ok?