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Motor runs for a second then dies
- Patton
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1973 Z1
KZ900 LTD
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- AnthonyKiser1977
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- 650ed
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1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- TeK9iNe
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- What did you do!?!
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I adjusted all of the float levels using the clear tube method, turned the four air screws all of the way in, left the two throttle cables disconnected, and turned the choke all of the up. After kicking a couple of times the engine sputtered a couple of times. After checking the plugs they are still dry. The inside of the carbs is spotless. The engine acted like it really wanted to run, but it just didn't.
OK, as ed said, the air screws are required to be open, at least 1/2 turn. Best at 1 - 1+1/2 "usually".
Is the "air screws" located closest to the engine side of the carb, or the air box side? If engine side - its a mixture screw, so unscrewing it adds fuel mixture. if air box side, then it is an air screw, so screwing out adds more air to pilot mixture.
What size pilots are in the carbs? Origional?
Have you made changes to exhaust/filtration?
Has a compression test been performed?
If engine has too low compression on 1 cylinder, and sync is not good, engine may not run after momentarily starting.
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79 Kawie Z1000 LTD
81 Kawie Z1000 CSR
83 Honda VT750C A
85 Kawie GPZ900 A2
86 Zukie GS1150 EG
93 Yamie XV1100 E
Lucky to have rolled many old bikes through my doors
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- AnthonyKiser1977
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- Patton
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They are the brass screws located towards the outside of the carb (legs). The only mods that the bike has are pod air filters, dyna green coils, and dyna plug wires. There is the jet by the float and the jet with the needle seat. What numbers should they have on them?
Imo, needle jets are inconsequential relative to the issue at hand.
Could try using some starter fluid sprayed through carbs.
If runs on the starter fluid, that's evidence of pilot circuit being clogged. Especially given good compression, valve clearances within specs, and proper float bowl fuel level, but dry plugs.
With proper fuel level, fuel/air mixture through pilot jet goes into carb throat and then sucked into combustion chamber.
Perhaps orifice at bottom of carb throat is clogged.
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1973 Z1
KZ900 LTD
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- Patton
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Has petcock sediment bowl been cleaned?
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1973 Z1
KZ900 LTD
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- Patton
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Could be from items such as:
Loose clamp onto carb holder;
Damaged or worn out carb holder;
Carbs not properly fully and fitted into carb holders;
Leaking vacuum caps;
Leaking emission lines or fixtures, if so fitted.
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1973 Z1
KZ900 LTD
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- Patton
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Thinking perhaps throttle slides were set too high during bench sync.
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1973 Z1
KZ900 LTD
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- AnthonyKiser1977
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