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What to Fix on Vacuum Prob?
- gravityoutlaw
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The bike a 1980 Z500 runs well through the gears until you want to cruise on the motorway then it starts to hold back like fuel starvation. I've run the test as per forum and the bike runs perfect with fuel cap open and tap on prime, but I can't find on the forum what parts to replace for the fix!
E.g do I need to rebuild petcock or fuel cap or both. Or is it just to replace diaphragm in petcock.
Can anyone please guide me
Cheers
Colin
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- Bluemeanie
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1980 KZ650F1, Bought new out the door for $2,162.98!
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- Locozuna
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KZ900LTD, KZ750LTD, KZ650, 72'Triumph Trident
"Over the Mountains
Of the Moon,
Down the Valley of the Shadow,
Ride, boldly ride,"
The shade replied
"If you seek for Eldorado!"
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- gravityoutlaw
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Cheers
Colin
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- Qdude
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- It is all good.
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Took me about a fortnight to finally suss it out. Good hunting!!
77 KZ 650 C1.
77 KZ 650 C1.
Crashed-Repaired, Pods, Kerker pipe, re-wired core bundle, lamp upgraded, homemade rectifier, solid state regulator , Dyna-s ignition, repainted, slightly modified, year-round commuter
Honda Metro 85 mpg Scooter. Dont laugh I will throw it at you
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- MFolks
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1982 GPZ1100 B2
General Dynamics/Convair 1983-1993
GLCM BGM-109 Tomahawk, AGM-129A Advanced Cruise Missile (ACM)
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- Bluemeanie
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The problem is still there with tap on "on" and cap opened, I could here the cap hissing when problem started after I got back from work! It might be a mixture of both cap & tap. Would it pay to get a new diaphragm for the petcock and a inline filter + check petcock for any restrictions?
Cheers
Colin
If your diaphram was bad it would be spraying fuel as one side has fuel and the other side has vacuum. Where do you have vacuum hooked up to?
1980 KZ650F1, Bought new out the door for $2,162.98!
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- Patton
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This entails removal of the petcock from the fuel tank, and complete disassembly of the petcock.
Correct reassembly is of course also required.
Fuel flow through vacuum operated petcock may be tested with engine not running by detaching the fuel line from the petcock, turn vacuum operated petcock to ON or RES (not PRI), detach vacuum hose from carb, use a syringe to supply vacuum to hose, and watch for fuel flow from petcock nipple.
On a vacuum operated petcock in ON or RES position (not PRI), the fuel flow is blocked by operation of a diaphram/o-ring/spring until vacuum is applied (which vacuum usually comes from a running engine).
Do you have for reference a parts diagram of the petcock?
Good Luck!
1973 Z1
KZ900 LTD
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- Patton
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Good Luck!
1973 Z1
KZ900 LTD
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- gravityoutlaw
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Cheers for all your inputs
Colin
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- Bluemeanie
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1980 KZ650F1, Bought new out the door for $2,162.98!
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