Brought home a ZX7- trouble shootin help!

[Garrett]

It doesn't run. The PO said he rode it to work and came out and it just clicked and nothing happened. He needed to unload it as it was his daily.
I figured it probably just filled the combustion chambers fuel and was locked so I put it in gear after I got it home and pushed it backwards and it starter button and it turned over a bit.
I pulled the plugs, they were dry. Tried cranking it and the start just clicked. Threw some mystery oil in the cylinders.
Put it back in gear and rocked it back and forth. We could feel it turn over :confused
Tried cranking it and it turned over maybe once then stopped. Put it back and forth and rocked it. Same thing. Turns over for a second then stops.

I pulled the ignition pick up cover off on the right side and turned it over with a wrench, it goes maybe ~170 degrees before the wrench stops turning and the crank stops, then I can turn it backwards to the same point, about ~170 degrees.
Held the throttle open and manually turned it over, all the intake valves are there AND moving with the motor.

I am going to pull the header this weekend and check the exhaust valves.

Are these known to drop exhaust valves? What else should I check?

sorry for the long winded post!

Thanks

[jwm2k3]

How many miles on it? Could it be electrical and not mechanical?

[Degsy]

Wirelessly posted

Im guessing by the 170 degrees and the crank stops turning part that this is mechanical. Lol.

"It was running when I put it away" is the biggest lie in biking.

Sorry.

[breakdirt916]

eww....when they don't turn over freely, I'm a little sketched out

so all the real stuff is good? battery/starter?

can you turn it over after pulling all the plugs out?

there has to be another explanation, but in my limited experience, I've only had a bike not turn over from 2 causes:
1.) the crank locked up (which doesnt sound like your problem, because it wouldn't move at all)
2.) I flooded the cylinder with oil leaving the bike on its side - pulling the plug, draining the oil from the crankcase, and tipping the bike over (it was a small dirtbike) solved that problem

I highly doubt you had either problem...

[Rambunctous]

Remove the plugs and turn it over by hand...Don't force anything...then get back to us

[jwm2k3]

Wirelessly posted

Im guessing by the 170 degrees and the crank stops turning part that this is mechanical. Lol.

Ya maybe I shoulda read that part eh?

[OreoGaborio]

Ya, maybe...

Get back to work

[Garrett]

I did turn it over with no plugs in it.

[Degsy]

Wirelessly posted

Can you rotate the motor through 720 degrees?

[TheIglu]

Could have one cylinder hydro-locked.

[Garrett]

Wirelessly posted

Can you rotate the motor through 720 degrees?

No sir. It goes about 170*.

[Degsy]

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You either have something very broken in there, like a crank bearing spun, broken rod. Dropped valve etc, or you are hydro locked. You state that all pistons are dry so hydrolocking is not a probability.

Check the oil for gasoline. If the oil looks way overfilled, take off oil filler cap and sniff for gas. Report back.

P.S. the likelihood is that you are going inside this motor, so start removing shit now so you're ready to take the valve cover off.

[breakdirt916]

how about this:

take 1 plug out at a time and repeat your engine turning - does it turn over more than the 170 degrees with each plug out?

and as degsy said - this might require surgery...external tests might not tell you anything...sometimes it's because something inside broke, and is jammed inside the gears

[Garrett]

Why would removing one plug at a time change anything when I did it all with no plugs in it?

[Degsy]

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Why would removing one plug at a time change anything when I did it all with no plugs in it?

It wouldn't. Ignore the doctor. Haha.

Don't force it. You may just have jumped a tooth on the cam chain.

[aldend123]

Why would removing one plug at a time change anything when I did it all with no plugs in it?

I don't know why removing it one at a time would be any better than none at all.

Ever heard of a borescope? If you know anyone who has one, that would be helpful to insert in to all the spark plugs, as well as the drain plug.

[jbmass]

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Don't force it. You may just have jumped a tooth on the cam chain.

Very possible, in which case it could have some damage.

[Degsy]

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Just take the valve cover off. Rotate the motor to the cyl 1 TDC mark and check cam timing to see if you jumped a tooth. Look inside intakes to see if you dropped an intake valve.

[Garrett]

I checked the intakes and all valves were present and moving.

[Degsy]

Wirelessly posted

Oh yes. That's right.
Even if it jumped a tooth, you may be ok. Once you fix whatever it is, a comp/leakdown will diagnose issues.

[TheIglu]

Could have a frozen valve guide. Saw that happen once, it cracked the cam caps and let the camshaft run free. Didn't want to budge.

[breakdirt916]

yeah, I think I was high...ignore that one

you said all plugs out - engine spins all the way, right?

all plugs in - engine only turns 270 degrees, right?

by some convoluted logic (based on what I had with the XR100 - it wouldn't turn over all the way because of the oil collection int he cylinder), I thought one of those cylinders was suspect with something in there as well - I was trying to find out which cylinder

[yzedf]

With plugs removed, put a long zip tie down each spark plug hole. When you turn the engine by hand do all 4 zip ties move? Up or down doesn't matter. If one of them (or more) doesn't move that's your problem. If not I'd pull the head off if there isn't anything obviously wrong.

[Garrett]

yeah, I think I was high...ignore that one

you said all plugs out - engine spins all the way, right?

all plugs in - engine only turns 270 degrees, right?

by some convoluted logic (based on what I had with the XR100 - it wouldn't turn over all the way because of the oil collection int he cylinder), I thought one of those cylinders was suspect with something in there as well - I was trying to find out which cylinder

Still high lol?

With plugs out, the engine moved like one hundred and seventy degrees. Putting them in makes no difference.

[Degsy]

Wirelessly posted

yeah, I think I was high...ignore that one

you said all plugs out - engine spins all the way, right?

all plugs in - engine only turns 270 degrees, right?

by some convoluted logic (based on what I had with the XR100 - it wouldn't turn over all the way because of the oil collection int he cylinder), I thought one of those cylinders was suspect with something in there as well - I was trying to find out which cylinder

Jesus. Lol.