Gio X31 keep stalling after accelerate hard

kk52736 · 05-19-2009, 03:29 PM

I got a new Gio X31 250cc dirt bike. Bike starts fine, but idle speed unstable (high then low then high). But a lots of time when after hard accelerate, the idle speed drop and stall the engine. I had tried to play around with the fuel/air mixture screw on the mikuni carburetor, but no luck. Should I adjust the needle for leaner mixture? I am at high altitude (approx. 6000ft above sea level)

katoranger · 05-19-2009, 04:07 PM

First make sure that the carb is secured to the intake manifold and the manifold bolts are tight to the head. You may have an air leak.

Then taken you elevation you bike might be running rich out of the box and you may have to do the reverse of most of us and adjust the carb needle to a higher setting. Most come in the middle. I would move it up one and see if you idle improves.

Also a new engine may need some time to break in before it will idle well.

forchetto · 05-19-2009, 05:03 PM

Katoranger could be right. One of the symptoms of a rich mixture is that when you blip the throttle the revs rise and then drop below the set idle speed or even die altogether.
Another is the varying idle speed, sometimes referred to as "hunting".

kk52736 · 05-19-2009, 06:08 PM

I had adjust the idle to higher idle speed, but that's not making any different after rev up hard and then it will drop below idle and stall.
if i start the bike on idle around 1500rpm for about a few minutes, there is a few times it will drop to like 500rpm and stall the engine.
if i am going to adjust the needle, should i check the spark plug first? how can i check if it is too rich or lean? and which way should i move the needle if needed, is it one notch to the end will get leaner?
and the fuel/air mixture screw, screw in for more air or less (it is located underneath the carb at the front side).
please help....

katoranger · 05-19-2009, 09:08 PM

On the needle. To lean it move it away from the pointed end and the screw I believe is to turn in to lean the mixture.

Not many of us are at 6000' of elevation so we all have to go the opposite direction.

Allen

AZ200cc · 05-20-2009, 02:06 AM

I'm at 7000, You'll have to lean it.....And make it breath as good as You can.

chupacabra250 · 05-20-2009, 09:51 PM

got one x31 last week too same problem here....

it was the GAZ TANK CAP not breathing enough, just remove the hose and drill a bigger hole like 1/8 to make your gas tank breathe more.

I do this and now its run perfect... hope its help you,its take me a while realise its was just the gaz tank cap

btw im new here, sry for my english im a french Canadian :roll:

katoranger · 05-21-2009, 12:49 AM

Would not be the first non-venting gas cap. Thanks for that tip.

Allen

05-19-2009, 03:29 PM	#1
kk52736 Join Date: May 2009 Posts: 2	Gio X31 keep stalling after accelerate hard I got a new Gio X31 250cc dirt bike. Bike starts fine, but idle speed unstable (high then low then high). But a lots of time when after hard accelerate, the idle speed drop and stall the engine. I had tried to play around with the fuel/air mixture screw on the mikuni carburetor, but no luck. Should I adjust the needle for leaner mixture? I am at high altitude (approx. 6000ft above sea level)
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05-19-2009, 04:07 PM	#2
katoranger Join Date: May 2007 Location: Altamont, Kansas Posts: 15,103	First make sure that the carb is secured to the intake manifold and the manifold bolts are tight to the head. You may have an air leak. Then taken you elevation you bike might be running rich out of the box and you may have to do the reverse of most of us and adjust the carb needle to a higher setting. Most come in the middle. I would move it up one and see if you idle improves. Also a new engine may need some time to break in before it will idle well. __________________ You meet the nicest people on a Honda Clone.
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05-19-2009, 05:03 PM	#3
forchetto Join Date: Jul 2008 Location: Gijon, Asturias,Northern Spain Posts: 396	Katoranger could be right. One of the symptoms of a rich mixture is that when you blip the throttle the revs rise and then drop below the set idle speed or even die altogether. Another is the varying idle speed, sometimes referred to as "hunting". __________________ Jincheng Monkey JC50Q-7 (two of them) Skyteam Dax replica ST110-6 (two of them) Zongshen ZS125-43 Qingqi QM200GY-BA Super Motard Yamaha Virago XV1100 Triumph Bonneville SE Qingqi QM110GY PGO Bug rider 250 Buggy
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05-19-2009, 09:08 PM	#5
katoranger Join Date: May 2007 Location: Altamont, Kansas Posts: 15,103	On the needle. To lean it move it away from the pointed end and the screw I believe is to turn in to lean the mixture. Not many of us are at 6000' of elevation so we all have to go the opposite direction. Allen __________________ You meet the nicest people on a Honda Clone.
	0

05-20-2009, 02:06 AM	#6
AZ200cc Join Date: Apr 2007 Location: Show Low Arizona Posts: 2,889	I'm at 7000, You'll have to lean it.....And make it breath as good as You can. __________________ <br />2001 Suzuki DR200SE<br />1997 Suzuki RM250 YIKES<br />1995 Yamaha Breeze 125 daughters<br />1991 Honda XR80r Restored<br />maybe a 2003 Yamaha TTR90
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05-19-2009, 06:08 PM	#4
kk52736 Join Date: May 2009 Posts: 2	I had adjust the idle to higher idle speed, but that's not making any different after rev up hard and then it will drop below idle and stall. if i start the bike on idle around 1500rpm for about a few minutes, there is a few times it will drop to like 500rpm and stall the engine. if i am going to adjust the needle, should i check the spark plug first? how can i check if it is too rich or lean? and which way should i move the needle if needed, is it one notch to the end will get leaner? and the fuel/air mixture screw, screw in for more air or less (it is located underneath the carb at the front side). please help....
	0

05-20-2009, 09:51 PM	#7
chupacabra250 Join Date: May 2009 Posts: 1	got one x31 last week too same problem here.... it was the GAZ TANK CAP not breathing enough, just remove the hose and drill a bigger hole like 1/8 to make your gas tank breathe more. I do this and now its run perfect... hope its help you,its take me a while realise its was just the gaz tank cap btw im new here, sry for my english im a french Canadian :roll:
	0

05-21-2009, 12:49 AM	#8
katoranger Join Date: May 2007 Location: Altamont, Kansas Posts: 15,103	Would not be the first non-venting gas cap. Thanks for that tip. Allen __________________ You meet the nicest people on a Honda Clone.
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