New carb, ZStar accels with zero throttle

HO14 · 04-01-2018, 05:52 PM

Hello,

I am certainly not very familiar with auto mechanics but I did determine that my son's ZStar wasn't starting due to a faulty carburetor. I purchased a new one; this one has a choke on the carb itself as opposed to the old one which had a lever that was engaged by the choke cabling.

Anyhow it starts right up but accelerates to very high speeds without any throttle. I dialed back the idling screw but this has not resolved the issue. Can't think of anything I've done incorrectly with the installation and am uncertain what to try next.

Any thoughts? Your comments/help is greatly appreciated.

david3921 · 04-01-2018, 11:14 PM

Welcome!
If you are using the stock cable, the new carbs cap might not be as deep as the stock one. This will cause the slide to ride high in the throat. Use either the stock cap on the new carb or measure the old cap and drill out the new one to make them match. Also, check that the cable is not twisted anywhere.

Bruce's · 04-01-2018, 11:29 PM

If it’s a mikuni type of carb ,the slide might not be installed correctly .

04-01-2018, 05:52 PM	#1
HO14 Join Date: Apr 2018 Posts: 1	New carb, ZStar accels with zero throttle Hello, I am certainly not very familiar with auto mechanics but I did determine that my son's ZStar wasn't starting due to a faulty carburetor. I purchased a new one; this one has a choke on the carb itself as opposed to the old one which had a lever that was engaged by the choke cabling. Anyhow it starts right up but accelerates to very high speeds without any throttle. I dialed back the idling screw but this has not resolved the issue. Can't think of anything I've done incorrectly with the installation and am uncertain what to try next. Any thoughts? Your comments/help is greatly appreciated.
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04-01-2018, 11:14 PM	#2
david3921 Join Date: Feb 2009 Location: Michigan Posts: 1,031	Welcome! If you are using the stock cable, the new carbs cap might not be as deep as the stock one. This will cause the slide to ride high in the throat. Use either the stock cap on the new carb or measure the old cap and drill out the new one to make them match. Also, check that the cable is not twisted anywhere. __________________ 2012 Kawasaki Versys 1984 Honda Magna V65 2016 Rhino 250 2016 Tao Tao 125D
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04-01-2018, 11:29 PM	#3
Bruce's Join Date: Apr 2015 Location: Sudbury ,Ontario Posts: 855	If it’s a mikuni type of carb ,the slide might not be installed correctly .
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