0 compression?!

Hey guys, rather confused so there are a couple questions here I think...

Background is a Kawasaki Z250, bought non starting and still non starting. I have rebuilt the carb (CV32, but have not removed/changed the float valve seat - not sure how, that's another question) and then realised I really should check the compression of the engine...the tester set arrived today and I tried to test for compression by removing the spark plug, opening the throttle and hitting the starter button.

Usually, I do get sparks from the spark plug, but for the compression test, I got a 0 reading. Nothing moved at all.

So first question relating to this thread is, are there any reasons why this might be? I checked the starter relay and it is good. I didn't have time to check the starter motor, but I'm under the impression that seeing as I am usually getting sparks from the spark plug, this is not the issue. Am I correct?

Secondly, this is the second time that I have been getting orange sparks from key hole, which heats up my key and produces a burnt smell. Dumb question, but is there a problem with my electronics? I have not noticed this before. With this key hole sparking issue, I have also noticed that my signals are not working anymore. My battery is reading at 12.52V when plugged into the bike, and I have been trying to give it a bit of a charger every month or so.

I guess thirdly, I am wondering what else should I be looking into to get the bike started? The reason I rebuilt the carb was that I wasn't getting any fuel through them when I tried starting the bike. Now that I have rebuilt and rejetted for pods (have not put in a new diaphragm or been able to remove the float valve seat as mentioned above), I am thinking that may be due to either of those reasons.

Any advice would be greatly appreciated.

Thanks.

I'm not really familiar with the z250s, but will give it a stab.

Is the motor turning over when your doing your compression check?
Make sure the fitting on the compression gauge is a tight fit. Even a loose fit should get a reading though.
If the electric start is not working, is there a kickstart on this model?
If so, you can use this to turn over the engine.
The engine will need to turn over to produce spark at the plug, so if you are not getting a compression reading, either the gauge is faulty, there's a valve open, or a hole in the piston.
Shine a bright light into the spark plug hole and have a look as you turn over the motor. You should be able to use a wrench on the end of the crankshaft to turn over the engine manually.

Do get yourself a service manual if you haven't already.

Sparks from the ignition lock is not good.
Something must be loose and shorting out.
You could check the wiring on the backside, and fix any loose or exposed/shorting wires, otherwsie a new ignition might be needed.

Check that the fuel level is correct for your carb.
If it's overflowing, then cleaning the seat & fuel shutoff valve may be needed, or replacements if already done. I believe the seat just threads in?

Do check the points or electronic ignition depending on which the z250 has, and all related wiring.
Check the ignition timing, valve clearances and other tune up maintenance items.

Welcome back Sham, hows the Sydney weather?
No compression is bad, it won't run that way. So remind everyone, did you have the engine apart? Or maybe the previous owner?
Have a quick check of the mechanical engine timing, not spark/ ignition. This would be to remove each of the valve adjustment caps, and the ignition cover. Get a wrench/ spanner to turn the motor by hand. First get it to the "T" mark. Then rock or turn the motor over a slight bit more and check to see if either of the valves are depressed by the rockers. If so, turn it backwards slightly to the "T" mark again and then just past. This should move the other rocker/ valve. If the mechanical timing is correct, then right at the "T" mark each should be just not moving, then when moving either way one should start to move. If neither move you are on the compression stroke, and this would be the time to check the valve clearances with a feeler gauge. Then turn the motor over 360 degrees, one full turn on the crankshaft and do the mechanical timing check.
If this checks out, Valves are set correctly, and mechanical timing is pretty close. Then you need to add compressed air to the cylinder down the spark plug hole when the motor is on the "T"T mark compression stroke. Then listen to where the air is escaping, at the exhaust or the Carb, maybe the Head gasket, Piston rings would show air escaping at the oil cap.

Hey guys,

Thanks for the replies.

I think everything was fitted on tight, so it must have been gauge or the engine itself. Thanks for the clarification that spark = engine is turning over, as I wasn't sure if this was the case and thought perhaps the engine isn't turning when I hit the starter.

Unfortunately there's no kick start - would have saved me from buying a new CDI if that was the case, which would have been great.

Its looking like this bike has quiet a few electric gremlins.

Motor Head, thanks - the weather has been crap and I haven't had much time to work on the bike, but I did finally get the a new carb manifold from z1. Mike was great - found me one from nowhere - its a discontinued part, and gave it to me for free.

I haven't had an engine tear down, and have been trying to avoid it for now as you can probably tell I'm very new to this. Will attempt to do the mechanical engine timing test over easter.

One thing I did notice today was that my starter motor isn't kicking in now - when I hit the starter button, I only hear the click of the relay. I'm pretty sure that wasn't the case when I got the 0 compression reading (remember hearing what I thought was the starter motor at least), but it would explain it if that's the case? So now it looks like I'll have to look into why this is so before I can try getting a reading again...

Starter motor not working, well that won't let you test much.
Make sure the battery is fully charged, both battery cables are tight at the battery. Check that the Ground/ earth at the engine block for the negative cable is clean and tight. Check the 2 big terminals at the Starter solenoid/ relay that you here click. Check the cable at the starter its self. If all you get still is the click sound at the solenoid, try jumping the 2 big terminals on the solenoid with a large conductor. Like a socket extension. If the starter still doesn't spin, and your certain of the battery and connections. Then the starter has to come off and apart for inspection. It could be a simple set of new brushes and a good cleaning to get it going. Or it may require a replacement. I'm sure one of your local Auto Electricians could check it for you. or follow just about any of the Kawasaki Manuals for how to rebuild a starter. They will have the electrical checks for you to follow. The one in my signature is for the 4 cylinder 1000 bikes, but he starter is much the same. Other than yours would have 2 instead or the 4 brushes.

Wow, FAIL!

So, I think I came across the reasons as to why I wasn't getting compression AND why I was getting sparks at the key...

1. Bike was not in neutral when I was trying to start it (duh)
2. Spark plug wire was NOT grounded against the engine, though I thought it was - let me explain - I had removed the spark plug and left the rubber connector lying against the engine, admittedly confused as to how this was grounding it, but not taking that thought any further...FAIL! So burning smell could be from CDI? MULTIFAIL

So, that's pretty much it from me.

Oh and compression measured off a cold engine - supposedly need to add 5% right? Won't make much difference...

30 PSI...fail.



At least I can now follow very clear steps as per the service manual to locate the problem...

So...what do you guys think the damage to the CDI will be? Man, so fail...

So that is as you know very low. The motor needs to be checked. The Valve clearances and mechanical, cam to crankshaft timing. Followed by the leak test, compressed air into the spark plug hole while on the "T" mark and compression stroke. If the motor is no good, needs a rebuild, then I guess you have to take that cost into consideration. You can add a small amount of motor oil down the plug hole and retest the compression. Are you sure the motor is spinning quick enough? You are holding the throttle wide open right?
I don't know if your new CDI unit would be effected by running the starter with the spark plug wire disconnected, I would hope not. I would recheck the connections, voltage, ground, signal across the coils, etc. Before saying the CDI was bad.

Hey Motor Head,

Yeh I'll definitely be trying to do those checks over the Easter weekend. Problem would be that I don't have a torque wrench, so I'll have to go looking for one.

Throttle was wide open.

I based the CDI damage off a website tutorial discussing the issues arising from not grounding a spark plug, but now I can't find it. Its not like it doesn't work, I guess I'm just worried I damaged it - kinda like denting a new car before you get to drive it kinda feeling?

Lol anyways, thanks for the input and I'll keep you guys updated on how the engine goes.