Bubbles coming from Head/Cylinder Gasket
- k1z947060
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Bubbles coming from Head/Cylinder Gasket
17 Dec 2017 08:42 - 17 Dec 2017 08:43
After recently reassembling the engine, I was adjusting the idle in the driveway and I noticed there was some drops on the ground below it. I looked and it seemed very watery (gasoline?) After looking more closely I saw that there were tiny little bubbles coming from various places between the head and cylinder. My compression tested at 90 PSI on a harbor freight compression tester.
Before I take this thing back apart - what all is likely going to be required to fix this?
Piston rings, head gasket, machining the head and cylinder surfaces?
Thank you,
Before I take this thing back apart - what all is likely going to be required to fix this?
Piston rings, head gasket, machining the head and cylinder surfaces?
Thank you,
1976 KZ400
Last edit: 17 Dec 2017 08:43 by k1z947060.
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- Patton
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Re: Bubbles coming from Head/Cylinder Gasket
17 Dec 2017 09:02
If not already done, would re-torque all head nuts/bolts when the engine is stone cold after sitting overnight.
Good Fortune!
Good Fortune!

1973 Z1
KZ900 LTD
KZ900 LTD
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- Nessism
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Re: Bubbles coming from Head/Cylinder Gasket
17 Dec 2017 09:05
Sounds like a head gasket leak. Did you clean the gasket surfaces and measure the head and cylinder to be sure they were flat? Use a torque wrench when installing the head? Use factory Kawasaki gaskets?
Ed
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0
www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know
1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0
www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know
1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
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- k1z947060
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Re: Bubbles coming from Head/Cylinder Gasket
17 Dec 2017 09:15
Yeah - I used an OEM gasket set, and I torqued it down in the sequence exactly like the manual said.
I cleaned all of the old gaskets off, but I would not be surprised if the surfaces weren't compeltely flat.
Reqtorqing the head would definitely be a easy solution. However, if I I waited to do that tomorrow, that will likely add 2 weeks to this fix...
I cleaned all of the old gaskets off, but I would not be surprised if the surfaces weren't compeltely flat.
Reqtorqing the head would definitely be a easy solution. However, if I I waited to do that tomorrow, that will likely add 2 weeks to this fix...
1976 KZ400
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- Patton
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Re: Bubbles coming from Head/Cylinder Gasket
17 Dec 2017 10:23
Just guessing, but perhaps 30 minutes of strong air flow from a box fan would cool everything down to ambient temperature before re-torquing.
Re-torquing is I believe best done after the first heat cycle.
Good Fortune!
Re-torquing is I believe best done after the first heat cycle.
Good Fortune!

1973 Z1
KZ900 LTD
KZ900 LTD
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- kevski
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Re: Bubbles coming from Head/Cylinder Gasket
17 Dec 2017 10:24 - 17 Dec 2017 10:25k1z947060 wrote: Yeah - I used an OEM gasket set, and I torqued it down in the sequence exactly like the manual said.
I cleaned all of the old gaskets off, but I would not be surprised if the surfaces weren't compeltely flat.
Reqtorqing the head would definitely be a easy solution. However, if I I waited to do that tomorrow, that will likely add 2 weeks to this fix...
If you do it while engine is hot it will potentially reduce your bank account by hundreds of dollars, trying to cool with a fan will not help, 2 weeks sounds better to me.
Last edit: 17 Dec 2017 10:25 by kevski.
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- Nessism
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Re: Bubbles coming from Head/Cylinder Gasket
17 Dec 2017 10:32
Put the fan on it. It only takes 30 mins or less to cool down. As long as you can rest your hand on the engine and not sense it as warmer than your body temperature you are fine.
Ed
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0
www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know
1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0
www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know
1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
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- k1z947060
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Re: Bubbles coming from Head/Cylinder Gasket
17 Dec 2017 11:36 - 17 Dec 2017 11:43
I already took the engine apart, because I'm impatient. Nothing felt loose. In fact, 5 of the 8 cylinder studs came out from loosenng the caps.
Could I just add gasket sealer/maker to the head gasket? Please pardon me if that's a dumb/novice question.
Could I just add gasket sealer/maker to the head gasket? Please pardon me if that's a dumb/novice question.
1976 KZ400
Last edit: 17 Dec 2017 11:43 by k1z947060.
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Re: Bubbles coming from Head/Cylinder Gasket
17 Dec 2017 12:31
Check flatness of the head and jug surfaces if out of spec it will happen again.
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- zukdave
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Re: Bubbles coming from Head/Cylinder Gasket
17 Dec 2017 15:32
DO NOT PUT ANY KIND OF SEALENT/SEALER ON A HEAD OR BASE GASKET !!!!!!!!!
1980 KZ650 F1
ZX750A1 motor.
Wiseco 810cc kit.
Zukiworks racing ported head.
VM 29 smooth bore's.
Dyna 2000 Ign. w/Dyna mini coil's
APE cylinder stud's and nut's.
APE valve spring's.
APE Track King clutch.
V/H KZ1000 sidewinder.
3.5x18 laced to a KZ1000 disk hub.
150/60/18 Shinko 006 Podium.
63" wheel base.
ZX750A1 motor.
Wiseco 810cc kit.
Zukiworks racing ported head.
VM 29 smooth bore's.
Dyna 2000 Ign. w/Dyna mini coil's
APE cylinder stud's and nut's.
APE valve spring's.
APE Track King clutch.
V/H KZ1000 sidewinder.
3.5x18 laced to a KZ1000 disk hub.
150/60/18 Shinko 006 Podium.
63" wheel base.
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- k1z947060
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Re: Bubbles coming from Head/Cylinder Gasket
17 Dec 2017 15:40
Okay - I won't. Now time to find some gaskets....
1976 KZ400
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