Compression in gear, but not in neutral

Hey everyone,

Just got a free 1978 KZ400 C1, I believe it is this morning, and my brother in law started to tinker around on it.
Here is what we have found so far, and hopefully you guys can shed some light on it:

Its a goofy situation... and something neither of us have seen before...
The bike has compression in gear but in neutral it doesnt... he can tell by taking the spark plug out and putting his finger over the hole.... It sucks his finger in and then blows it out on the exhaust stroke.

Thanks for any help guys!

I don't understand what your telling us. Please describe in more detail how this is being tested. Are you saying you put the bike in gear, pull in the clutch, put your finger over the spark plug hole, and hit the starter and you can feel compression but when you try this with the bike in neutral there is no compression? What makes you believe it is not sucking his finger in on the intake stroke and blowing it out on the compression stroke? Ed

Thanks for the response, 650ed! It does suck it in on the intake and blow it out on the compression. No electric start, just a kick start

is the bike a female? :woohoo: :woohoo: :woohoo: :woohoo:

what are you considering neutral, the clutch handle pulled in?

If you push bike in gear it has compression?

hahaha heard that!!! :woohoo:

yes, neutral with the clutch handle pulled in while trying to kickstart.

and yes, when the bike is pushed in to gear it has compression.

Thank you guys very much for the responses!

First motorcycle, and it was free. Trying to learn, but need some serious help!

Pull in clutch and push kicker = zero anything. When you do that you are disengaging any connection between the kicker and the crankshaft. Don't pull in the clutch if you are kickstarting it. Ed

Ok, and the compression will be there then?

ok Ed is right,

kick start gear drives the clutch basket gear that turns the engine over.

If you compress the clutch it dis engages the clutch plates causing the basket to spin in place not turning the engine over

Ok perfect! Thank you guys so much for your help! I will hopefully get a chance to try it tonight, and see how it goes. I would've never been able to get it to go without your guys's help. Post soon!

Do you have a shop manual? If not, look at these websites:
Manuals (Some of these websites sell used manuals, just ask)
www.repairmanual.com Manual)
www.manualsnmore.com
www.midwestmanuals.com/
www.books4cars.com/
www.repairmanualclub.com/motomanuals/
moto-manuals.com/
www.e-classicbike.com/
www.repairthatmotorcycle.com/manuals/kawasaki.html
www.manualedereparatie.info/en/categorii/kawasaki.html