80 kz750 4 cyl power stalls on full throttle

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80 kz750 4 cyl power stalls on full throttle

07 Apr 2012 19:37
#514587
My kz750 suddenly had a loss of power when i was riding it, and now it backfires and dogs down on full throttle. if you turn the throttle slowly it revs up without a problem, any ideas as to where I should start? Im pretty sure that its not the carbs because they were just cleaned.

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  • 650ed
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Re: 80 kz750 4 cyl power stalls on full throttle

07 Apr 2012 19:42
#514588
What are you using for air filtration?
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)

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Re: 80 kz750 4 cyl power stalls on full throttle

07 Apr 2012 19:46
#514590
k&n pods, has a kerker pipe and mikuni vm29 smoothbore carbs.

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Re: 80 kz750 4 cyl power stalls on full throttle

07 Apr 2012 20:16
#514595
I'm positive others with solid hands-on experience will chime in with good advice, but 29mm smoothbores & pods sounds like a lot of carb for a stock KZ750 unless the carbs are tuned down a bit. Maybe someone can offer suggestions on appropriate jetting. Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)

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Re: 80 kz750 4 cyl power stalls on full throttle

07 Apr 2012 20:19
#514597
Im pretty sure it has nothing to do with jetting since the bike ran great before the other night I would full throttle it and it would get up and go,

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Re: 80 kz750 4 cyl power stalls on full throttle

07 Apr 2012 20:37
#514599
How long ago were the carbs cleaned? Could one of the jets have worked themselves lose? Are there air or vacuum leaks on the carb holders?
1977 KZ650 B1
Pods and Denco header

OLD KAW OWNERS SMILE ALOT

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Re: 80 kz750 4 cyl power stalls on full throttle

07 Apr 2012 20:48
#514601
I always wonder about fuel, sitting and getting old and water ladden when fuel problems happen this time of year after sitting for a long time. Take the tank off and drain it and start fresh if their is any doubt. use the old fuel in a cheap lawnmower if you must.

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Mr Turbo Race Kit, MTC 1075 Turbo pistons by PitStop Performance , Falicon Ultra Lite Super Crank, APE everything. Les Holt @ PDM's Billet Goodies . Frame by Chuck Kurzawa @ Logghe Chassis . Deep sump 5qt oil pan. RIP Bill Hahn

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Re: 80 kz750 4 cyl power stalls on full throttle

07 Apr 2012 20:51
#514603
the carbs were cleaned about a week ago, and there are no cracks or leaks in the carb boots everything is secured tightly. and on the gas its my third tank in the last week

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Re: 80 kz750 4 cyl power stalls on full throttle

07 Apr 2012 23:55
#514634
Perhaps there's an issue with the ignition advancer being slow to reach open position.
Might need lube, or clean and lube.




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1973 Z1
KZ900 LTD

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Re: 80 kz750 4 cyl power stalls on full throttle

08 Apr 2012 18:07
#514740
the ignition advancer is clean and moves freely, I discovered that it runs better with the choke on and if I turn the air mixture screws in all the way it runs better with the choke off. but still doesnt have as much power as it should.

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Re: 80 kz750 4 cyl power stalls on full throttle

08 Apr 2012 18:35
#514743
Have the float bowl fuel levels been measured using the clear tube method?

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Re: 80 kz750 4 cyl power stalls on full throttle

08 Apr 2012 22:40
#514774
Take off the petcock and clean the screens that are on top of the petcock and inside the tank.
KD9JUR

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