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81 Kz650 hangs on revs.
- ShouterVW
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I am running stock airbox, and a Mac 4into1 with 102.5 mains, and 17.5 pilots. Stock 1981 needles with the thick washer on top of eclip, and thin on bottom of eclip. My air screws are currently at 2.5 out each. I started at 1.5 and then read it should be 2.5. It does the same thing at each setting. Speaking of the air screws, I have the screw with a spring on it, no o ring. I am assuming That is the way it's supposed to be? Any help would be appreciated!
Also, my valve clearances check in spec, and my ignition advancer is free and springs back. The spring tension is not very strong. Not sure how stiff it is supposed to be.
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- 650ed
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1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- ShouterVW
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- 650ed
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1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- ShouterVW
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- Patton
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And assure all vacuum caps/plugs are present, fitting properly and in good condition.
Could also test for air leak in the vacuum hose to petcock -- remove the hose from its vacuum nipple, plug/cap the nipple, switch petcock to PRIme position and test run. This should discover or rule out a vacuum hose leak or possible air leak from an internally defective petcock.
Air may also leak through worn or defective pads on the choke plungers.
Question -- is the clean-air system still fitted? (It has various air-leak-prone hoses and components.)
Could also resort to spray testing with WD40, because it produces smoke from the exhaust when ingested through an air leak source.
Good Fortune!
1973 Z1
KZ900 LTD
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- ShouterVW
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- ShouterVW
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I do not have vent tubes on the 2 vents on the carbs. Just open to atmosphere. Is it a requirement to have tubes there?
Also. Right now I am only running a pull throttle cable, as my push one was broken. This should have no effect on the action of the assembly? It closes and opens as it should
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- 650ed
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1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- ShouterVW
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- martin_csr
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The air screws don't have grooves for o-rings, so you are fine without o-rings
I don't have them on my 81 650-CSR & it runs fine.
I don't know much about the jetting, but if you have the stock airbox, the stock pilot jets might be fine (#15). Not sure if it matters, though.
If your advancer snaps back & the springs look normal, then it's probably fine.
Rusty or stretched out springs would be cause for concern.
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- Patton
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ShouterVW wrote: I no longer have the vacuum Petcock. And the corresponding vacuum nipple on the carb is plugged. I also got rid of the clean air crap, branched the ports on the valve covers, and capped the 2 nipples on the carb boots. I never thought of the choke plungers. Will spraying them do any good?
Would double-check the other possible air leak sources before investigating condition of the plunger pads. Worn or damaged pads are more likely to admit fuel rather than air when the plungers are fully down (choke OFF). In the case at hand, would just assure that all four choke plungers are closing fully down when the choke is off.
Good Fortune!
1973 Z1
KZ900 LTD
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