- Posts: 6
- Thank you received: 0
No Compression (WHY)
- EEcor999
- Topic Author
- Offline
- User
The thing that gets me the most is that it was running fine before I took the head off and now all of a sudden there is no compression, WHY.
Thanks
Please Log in or Create an account to join the conversation.
- tjhiggin
- Offline
- User
- Posts: 169
- Thank you received: 1
T.J. in Huntsville, Alabama
1983 KZ1100-A3, 1974 Honda CB550-4
Previous bikes: CB100, TS125, CB175, KZ400, CB500-4
Please Log in or Create an account to join the conversation.
- MFolks
- Offline
- User
- Posts: 6650
- Thank you received: 540
Finding the cause of no compression can only be just a few things.
1982 GPZ1100 B2
General Dynamics/Convair 1983-1993
GLCM BGM-109 Tomahawk, AGM-129A Advanced Cruise Missile (ACM)
Please Log in or Create an account to join the conversation.
- EEcor999
- Topic Author
- Offline
- User
- Posts: 6
- Thank you received: 0
Please Log in or Create an account to join the conversation.
- littlemanonbigbike
- Offline
- User
- Posts: 76
- Thank you received: 0
On my 1100 it is 44 links front to rear. it should expain it in your manual.
1982 1100 Spectre
Various other toys
Please Log in or Create an account to join the conversation.
- EEcor999
- Topic Author
- Offline
- User
- Posts: 6
- Thank you received: 0
Please Log in or Create an account to join the conversation.
- bountyhunter
- Offline
- User
- Posts: 7246
- Thank you received: 337
no I did not set the valves but that would make the compression get a lot higher because the valves would not open far enough. Right. but I am getting like NO compression, and I do not understand why.
No, it surely would not. The valves would be staying partly open all the time. If they are not seating tight your compression will be crap, just like you are reading.
When they machine qa head they cut the seats deeper, and that means you either have to grind the valve ends (which they probably didn't do) or you have to install thinner shims to restore valve clearance.
1979 KZ-750 Twin
Please Log in or Create an account to join the conversation.
- steell
- Offline
- User
So I Took the head off had it machined and the valves were redone also
What do you mean by "had it machined"?
If it involved removing material from the mating surface of the head, then the cams are at least a little out of time. The more material removed, the further out of time the cams will be.
Did you install the cams wrong the first time, hear a "clunk" when you turned the motor over, then go back and time the cams again?
I'm asking because that is a real common error, and the usual cause of no compression after installing the head.
KD9JUR
Please Log in or Create an account to join the conversation.
- BSKZ650
- Offline
- User
- Posts: 2064
- Thank you received: 14
before removing the head, pull the cams and use a compressor to fill the clys with air, if they hold air, then its valve adj, if it comes out the ex or intake,, sadly remove the head, bent valves
77 kz650, owned for over 25 years
77 ltd1000, current rider
76 kz900, just waiting
73 z1,, gonna restore this one
piglet, leggero harley davidson
SR, Ride captian, S.E.Texas Patriot Guard Riders.. AKA KawaBob
Please Log in or Create an account to join the conversation.
- Patton
- Offline
- KZr Legend
- Posts: 18640
- Thank you received: 2098
Air escaping through a leaking exhaust valve will be heard at the exhaust port or inside the exhaust system.
Air escaping through a leaking intake valve will be heard at the carb intake.
Air escaping past the pistons and rings will be heard at the crankcase vent.
A leakdown test is quick, easy and unintrusive, and requires no disassembly other than removing a spark plug in the cylinder being tested. The test is of course performed when the engine is not running, and renders a lot of information about overall condition of the engine.
A tester is sometimes available as a loaner tool from local auto-supply dealers such as AutoZone.
Z1E also carries the loadtest tool.
The tool diagnoses the source of the compression leak. It of course does not remedy the cause of the leak.
Good Luck!
1973 Z1
KZ900 LTD
Please Log in or Create an account to join the conversation.