79 kz1000 st no compression on all 4 cylinders

Hi gents.. Picked up a 79 kz1000 st really good shape frame and engine very clean..it needed all electrical but i had all this already from another kz1000.

I have zero compression on all 4 cylinders.. I put oil in the cylinders still nothing.. so I am leaning towards stuck valves as its been sitting for years..

I took the vavle cover off, but not sure what to check exactly. first time this happens to me.

When the shaft turns, The Cams do push down on the shim and the lifter goes down a bit then up.

How do i know if the valve is actually moving do I have to take the top end off??

Also I did not even check the TDC and timing marks if that was wrong could i get a zero compression symptom?


thanks

Something sounds wrong. Please describe how you checked the compression. Ed

A new or rebuilt engine might have 180 PSI, one with a few years/miles maybe 130, anything lower might run but will have little power. You get as low as 100 PSI and it's rebuild time.

To test compression, I removed spark plugs, screwed in compression tester.. nothing happens when turning engine over.does not even register 10 Psi.

The tester works I tested it on my other bikes fine that same time.

Let me add this info. I got this bike for Free. Neighbor had it in his truck box was going to dump it since his son never used it in 15 years.. the frame was repainted and new gaskets seem to gave been added to engine block, so maybe they tried a rebuild and gave up something could of gone wrong.

So you have all the plugs out, throttle wide open,and crank the engine with the electric starter and you get a reading of zero on every cylinder? I don't know how an engine can get to that state unless the previous owner removed the pistons, punched holes in all 4, destroyed at least 1 valve in each cylinder, or has the valves WAY out of adjustment. Can you use a feeler gauge to see if there is any clearance between the valves and cams? If the valve clearances seem ok, I would try using an air compressor and spark plug hole adapter to pressurize the cylinders 1 at a time with their valves in the closed position to see if you can hear where the air goes (intake / exhaust / or crankcase). If it's not a valve adjustment issue, it's going to be very interesting to see what you find inside this engine when you pull the head. Afterthought - can you tell if pressure is leaking badly from head gasket when you crank it? Ed

Zero compression? Failed cam chain resulting in a bunch of bent valves?

Can you use a feeler gauge to see if there is any clearance between the valves and cams?

That's the next thing you should do. My guess is bent valves.

Bent valves will cause zero compression, been there, done that.

maybe someone put it back together and rebuilt it incorrectly. check out my kz1k motor project thread. youll get a kick out of it. REBUILT IT AND THEY WILL COME!!!!


btw, what is no compression? 0? i had 40 lbs in all 4 cylinders.....sending out head, and starting from the bottom up with a nice cleaning and new hardware. ganna get new piston rings and cam chain also. my bike was free too, but it was in a box.:woohoo:

Question --- With cold engine, will shims move when cam is pointed away from them?

If shim won't even move, likely there's no clearance at all, whereby valve can't seat and therefore won't seal, resulting in loss of compression through the unseated valve.

With correct valve clearances, and still no compression, could perform leak-down test to help determine which valves are leaking.

Good Fortune!

Thanks for all the help, I'm looking at what your asking when I get some time..

I took Pictures of the Bike, Remove the Pickup cover and used 17mm socket to rotate to TDC..Piston #1 and #4 seem to be at TDC..I could not align it exactly as it seems to have so resistance just about at TDC like its hitting something..if I forced a it it does turn over but near TDC something is Rubbing/grabbing.

see pictures below..

-Bike,
-TDC

intake cam " looks to be aligned/timed ok, but not sure about the 28th pin mark.

but the exhaust cam I don't see the Timing Marks on it when I am at TDC. I guess my problem is here?

Also if I need to rotate the exhaust cam, I need to do something on the chain tensioner?? From what i can see lossen the bolt and just add a longer one in??does it have to screw in?? not sure how this works?

again any help appreciated..

pic should be attached below shortly

sounds like its time to pull the head and check the valves