carb adjustment

smokeeater · 03-24-2008, 09:53 AM

its been awhile since I messed around with carb adjustments and can't quite remember how to start. After fixing the electrical problem with my son's atv (70cc hensim tierra), Its tough to start and doesn't want to stay running. Can anyone give any good guesses as to how many turns out from closed to open the air mixture screw?
The problem is, I have to hold the throttle wide open for appx 15 sec, several times for it to start. choking it doesn't help

ejcycles · 03-24-2008, 10:27 AM

Hi smokeeater

It sounds like you have an internal carburetor problem.
If you need to hold the throttle at W.O.T. to get it to start, it's flooding. Holding the throttle at W.O.T. lets more air in so it gets rid of the excess fuel and the engine will start a little easier after it gets rid of the fuel it doesn't need. The first thing you should do is get rid of the stock factory spark plug and install a NGK C6HSA and gap it at .026 thousandths. The second thing is to make sure that the float inside of the carburetor isn't sticking or dirt caught in it's needle. This is the biggest problem when a vehicle floods itself.

smokeeater · 03-24-2008, 12:05 PM

I have a new c7hsa and the gap was right on. the tip is white, correct me if i am wrong, does this mean it has a lean mixture?

nick780 · 03-24-2008, 03:44 PM

smokeeater, yes i think i white tip means your running lean. and as for your fuel mixture screw, turn it clockwise untill you have it closed, then back it out 2 full turns, that should get you close to the right mixture,( clockwise=lean,,counterclockwise=rich),

03-24-2008, 09:53 AM	#1
smokeeater Join Date: Mar 2008 Location: metro detroit Posts: 24	carb adjustment its been awhile since I messed around with carb adjustments and can't quite remember how to start. After fixing the electrical problem with my son's atv (70cc hensim tierra), Its tough to start and doesn't want to stay running. Can anyone give any good guesses as to how many turns out from closed to open the air mixture screw? The problem is, I have to hold the throttle wide open for appx 15 sec, several times for it to start. choking it doesn't help __________________ <div align="left">hensim 70cc atv, son's<br />'92  250x, mine<br />'01 recon, hers<br />'95 xcr 600<br />'89 four winns <br /></div>
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03-24-2008, 10:27 AM	#2
ejcycles Join Date: Oct 2006 Location: 11481 State Route 44 Mantua, Ohio 44255 Posts: 1,112	Hi smokeeater It sounds like you have an internal carburetor problem. If you need to hold the throttle at W.O.T. to get it to start, it's flooding. Holding the throttle at W.O.T. lets more air in so it gets rid of the excess fuel and the engine will start a little easier after it gets rid of the fuel it doesn't need. The first thing you should do is get rid of the stock factory spark plug and install a NGK C6HSA and gap it at .026 thousandths. The second thing is to make sure that the float inside of the carburetor isn't sticking or dirt caught in it's needle. This is the biggest problem when a vehicle floods itself. __________________ Thanks, Bruce @ Endless Journey Cycles "Phone Calls Only" ~330-274-0098~ Hours: Tue.-Fri. 10:00-6:00 Sat. 10:00-4:00 EST. Dealer for: Lifan, Crossrunner ATVs. http://www.endlessjourneycycles.net
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03-24-2008, 12:05 PM	#3
smokeeater Join Date: Mar 2008 Location: metro detroit Posts: 24	I have a new c7hsa and the gap was right on. the tip is white, correct me if i am wrong, does this mean it has a lean mixture? __________________ <div align="left">hensim 70cc atv, son's<br />'92  250x, mine<br />'01 recon, hers<br />'95 xcr 600<br />'89 four winns <br /></div>
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03-24-2008, 03:44 PM	#4
nick780 Join Date: Feb 2008 Posts: 37	smokeeater, yes i think i white tip means your running lean. and as for your fuel mixture screw, turn it clockwise untill you have it closed, then back it out 2 full turns, that should get you close to the right mixture,( clockwise=lean,,counterclockwise=rich), __________________ 2007 Roketa atv-61 300cc , 2003 suzuki LT-Z400,,jet kit,,white brothers exhaust
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