Only running on 2 cylinders

KZCSI wrote:

All cylinders fire a few degrees before top dead center on the compression stroke. However cylinders 2 & 3 are never on the same stroke. When cylinder #3 is firing cylinder #2 is on just finishing the exhaust stroke.

I'd check the valve adjustment and the compression then I'd go back to the ignition as these two cylinders share a coil.

Bill

stroke is distance the piston travels from lowest point to highest point
1 & 4 and 2 & 3 in pairs ,make this journey AT THE SAME TIME
yes exhaust stroke and compression stroke are of course diff, but thats not what we were talking about, it was when the plugs fire OK ???

Dylansword wrote:

...trying to start, but wont...Whats the first thing i should check?

Remove plugs and observe sparks while spinning engine.
Look for fat blue sparks (not weak orange sparks).

Best to install all brand new plugs, because one non-firing plug in the coil's secondary loop prevents the other plug in that same loop from firing.

Good Fortune!

[Click on image to enhance view.]

Dylansword wrote:

I have a 77 kz650, it was running great when i got it. Now its not running right. It has 4-1 exhaust, and accel coils and wires. The problem is, it is only wanting to run on cylinders 1 and 4. Its not the coils, ive tested them, and switched them around, and it still doesnt run right. Ive pulled the carbs of many times, and cleaned them, and blown them out with air. It has the dyna ignition, so i switched it back to points. When it is running, cylilders 2 and 3 both have spark. So im not sure why it is running bad. What else could it be? Cam timing? If so how do i check it? Please post any help. or questions.

#1 Do you own a service manual?
#2 Do you have a multimeter or Volt/Ohm meter?
#3 Do you have a compression gauge?

Cam timing does not change other than if the chain tentioner is failing (in which case the engine would sound terrible @ idle), an old chain changes the timing, but only slowly over time effecting performance, would still start.

Check compression. Actual numbers off a good gauge are best... and yes, the compression can suddenly go bad on 2 cyl or more if they were being run too lean.

How do you know 2-3 cylinders are getting spark? You checked them against head of engine and looked for spark?
This does not mean that the coils are producing enough power to spark the gap under compression.

CHECK COIL VOLTAGE - Should be very close to battery voltage, maybe just a couple .1 off.

BATTERY VOLTAGE must be 12.6 - 12.8 Volts once the battery has sat serveral hours after charging.
If battery is 12.6 Volts or less after charging/overnite sitting - BAD/DYING BATTERY - check electrolite level and increase with distilled water/aproved acid to proper level. If sealed type, then replace, or use a known good car battery for testing.

Start with these, and report. Assumptions make troubleshooting impossible. Facts only.
Can't say compression must be good, cause it was running yesterday... :laugh:

Best of luck.

Patton wrote:

Remove plugs and observe sparks while spinning engine.
Look for fat blue sparks (not weak orange sparks).

Best to install all brand new plugs, because one non-firing plug in the coils secondary loop prevents the other plug in that same loop from firing.

Yes, good info... Plugs must be held against a good ground (ie. engine case/head) to spark, also check grounds from batt to case, etc.

New plugs, deffinately.

now we only need one more person to say the same things again and we'll officially have an echo chamber :ohmy:

stonemaster wrote:

now we only need one more person to say the same things again and we'll officially have an echo chamber :ohmy:

:laugh: Dont forget to confirm at least 110 lbs compression @ each cylinder... probly not compression, but good place to start...

Batt voltage...???

Compression... spark... fuel/air in correct ratio... timed correctly... compression...

:evil:

Pretty sure that covers it!

Don't worry, we'll be here ot poke fun at eachother till you solve this! :woohoo:

ok, so i ordered a new set of points and condensors. and they finally came today. And i put them on, and it didnt change anything. Still doesnt want to start.

Btw it has mew plugs, i put new, high end, plugs in a little while ago when i was trying to fix it.

I screwed with the points gap a little, and it didnt rele change anything, as well as the timing. I pulled the plugs to check the gap and they were at the correct gap, so i opened them up a bit. (.035) And it is still not wanting to start. I pulled plugs 3&4 and checked for spark, and they had good spark. They did look a little wet, and smelled like gas.

I have the adjustment screw's on the carbs about 1/4 turn out from all the way in.

I have the original service manual, volt meter, and comp gauge. I checked comp when this all started and it was fine.

What should i check next?? Carbs again? Timing?

Thanks everyone

Dylansword wrote:

ok, so i ordered a new set of points and condensors. and they finally came today. And i put them on, and it didnt change anything. Still doesnt want to start.

Btw it has mew plugs, i put new, high end, plugs in a little while ago when i was trying to fix it.

I screwed with the points gap a little, and it didnt rele change anything, as well as the timing. I pulled the plugs to check the gap and they were at the correct gap, so i opened them up a bit. (.035) And it is still not wanting to start. I pulled plugs 3&4 and checked for spark, and they had good spark. They did look a little wet, and smelled like gas.

I have the adjustment screw's on the carbs about 1/4 turn out from all the way in.

I have the original service manual, volt meter, and comp gauge. I checked comp when this all started and it was fine.

What should i check next?? Carbs again? Timing?

Thanks everyone

STOP! If you don't listen to what these guys are telling you then most likely you're just going to end up a little lighter in the wallet from throwing away money on parts that you may not need. CHECK THE BATTERY FOR PROPER VOLTAGE....STOP.... CHECK THE COILS FOR PROPER VOLTAGE....STOP.... CHECK THE SPARKPLUGS FOR FIRE....STOP.... CHECK FOR PROPER TIMING....STOP.... CHECK FOR FUEL AT THE CARBS....STOP.... CHECK COMPRESSION.... It only needs 3 things to run being fuel, air, and spark. If you have verified spark and air already check for fuel. Make sure your air filter/s are clean also.

For reason's unknown but to Kawasaki, the 550's,650's and 750's ignition coils primary(small wires)are different from the 900's,Z1's,Kz1000's and Kz1100's.

The smaller bikes primary wiring is having the RIGHT COIL fire #1 & #4 and the LEFT COIL fire #2 & #3.

On the bigger 4's is just opposite:

The LEFT COIL fires #1 & #4 and the RIGHT COIL #2 & #3.

Dyna is notorious for leaving you on the side of the road at any given time, check to make sure you have bike wired up right at coils, plugs wet and smelling of gas sounds like you might have plugs wired backwards, still get spark but would be on the wrong stroke.

okay.......

The battery is at correct voltage, its sitting on a battery tender.

There is the same voltage as the battery at the coils.

The spark plugs are firing

****Timing i am unsure on, i am unsure how to get it correct. The book doesnt do a good job explaining it.

The carbs definatly have fuel

And as i said i already checked comp and it was fine.

As for the ignition, i took off the dyna s ignition and put points back on it, The points and condensers are brand new. And i JUST rewired the entire ignition, from the points to the coils.

Start simple, what's your battery voltage?

Next, what's the voltage at the coils?

The reason everyone is focused on your ignition and not your carbs (which you keep asking about) is because the ignition affects those 2 cylinders simultaneously, whereas a carb problem would only affect one cylinder. So unless you have a good reason that the carbs aren't working, we're going to assume that they're good to go.

Assuming the carbs are good, your cam timing and compression don't really change at all unless someone messes with something big. Have you ripped apart your motor recently? No? Ok then forget about cam timing and compression, because they're fine.

Now we're back to the ignition system. Since we know one coil is working properly, and since we know that when you swap them the other coil works properly, that rules that out. Hence the reason we're working our way back. Check the voltage at the coil. Bad/rusty/worn/broken connections and wires are very common on these old bikes. Hell the problem could be as simple as a faulty fuse dropping voltage. We don't know until we get some numbers on your voltages.

If they all check out, we're moving on to the points. But first things first, go get the multimeter!