bike stutters at speed

bronevaya · 02-08-2008, 09:30 PM

ever leave the choke on when you start driving fast and the bike kinda sputters? well thats what its like for me when i am driving at high speed (above 20-30). It will drive and sputter (like its about to die or something) but it never dies and it only does it when I am on the throttle.

I havent ridden the bike in maybe a two weeks and now its sputtering.

the oil seems low, could that be the problem?

the GAS tank is about half full.

pacman · 02-09-2008, 04:16 AM

Check the choke adjuster on the carb. It may not go all the way back.

A lot of things will cause the engine to stutter. Fouled sparkplug. Dirty airfilter. misadjusted air/fuel ratio just to mention a few.

AZ200cc · 02-09-2008, 10:19 AM

Condensation?

warrior91 · 02-09-2008, 11:53 AM

My vote is check sparky.

bronevaya · 02-09-2008, 05:40 PM

well i changed the oil, put in some seafoam and changed the plug from the ngk to the one that came with the bike. the plug was sooty, but I dont know whats normal and whats not. the bike rode good, better then before, but I still felt tiny hesitation once. I will need to ride it further I guess to see if its completely gone.

bronevaya · 02-09-2008, 06:37 PM

update:

damn, still there, whats the damn deal :( :( :(

MATT · 02-09-2008, 08:09 PM

from what I've heard a few people on this form have had success changing the plug cap.

Second-Lap-Motorsports · 02-09-2008, 10:49 PM

Is there any smoke coming from the muffler? Black smoke would indicate a rich (too much fuel) condition. If the spark plug continually looks sooty or wet/oily it also would be a sign of a rich condition. If you have either of these problems, look for a dirty air filter first, and clean/re-oil as needed. Then if the filter was not dirty the carb may need to be serviced, and look for a sticking or damaged inlet needle or damaged float.

Steve

pacman · 02-10-2008, 02:27 AM

Did you check the choke? If the spark plug is sooty, your choke may be stuck.

Suprsignet · 02-10-2008, 11:37 AM

I agree that it sounds like your bike is running a little rich. If the choke adjustment doesn't help, you can adjust the air/fuel mixture. It is asy to do, but if it is your first time playing with a carb, you should have someone help you just so things don't get too out of whack.

bronevaya · 02-10-2008, 04:14 PM

well how should i go about adjusting it?

Suprsignet · 02-11-2008, 12:07 AM

If you look at your bik's carb thre will be 2 brass screws. One is for adjusting th idle and one is for adjusting the air fuel mixture. The one with the spring on it is the idle screw. The small one with no spring is the air fuel screw.

When adjusting the a/f mix make sure to refrence where you start with a sharpie or something (as this is your first time) and only back the screw off or turn it in 1 quarter turn max at a time. Turn the screw and then test ride the bike.

Backing the screw out makes the bike leaner and turning it in makes the bike richer.

From the sound of your problem and spark plug state it sounds like your engine is running rich. If you have never done this before take your time and only make small adjustments.

bronevaya · 02-11-2008, 04:17 PM

I tried adjusting it to no avail, I am about to give up and take it to a shop :x

Second-Lap-Motorsports · 02-11-2008, 09:06 PM

Where are you located? If you are close to Owosso, MI I would be willing to help you out for cheap.

Lifanrider · 02-11-2008, 09:37 PM

okay folks I read in another thread that turning the mixture screw counterclockwise enriches the mixture, here I read that it leans the mixture. Could someone please provide clarity on the this issue? thx.

02-08-2008, 09:30 PM	#1
bronevaya Join Date: Jun 2007 Posts: 162	bike stutters at speed ever leave the choke on when you start driving fast and the bike kinda sputters? well thats what its like for me when i am driving at high speed (above 20-30). It will drive and sputter (like its about to die or something) but it never dies and it only does it when I am on the throttle. I havent ridden the bike in maybe a two weeks and now its sputtering. the oil seems low, could that be the problem? the GAS tank is about half full.
	0

02-09-2008, 10:19 AM	#3
AZ200cc Join Date: Apr 2007 Location: Show Low Arizona Posts: 2,889	Condensation? __________________ <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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02-09-2008, 11:53 AM	#4
warrior91 Join Date: Nov 2007 Location: N.E. Saskatchewan, Canada Posts: 679	My vote is check sparky. __________________ '91 Yamaha Warrior- stage 2 '83 Honda ATC 70 '08 Yongjiang 125cc mx (Loncin) '08 Yongjiang 150cc atv (Jinlong)
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02-09-2008, 10:49 PM	#8
Second-Lap-Motorsports Join Date: Feb 2008 Location: Owosso, MI Posts: 22	Is there any smoke coming from the muffler? Black smoke would indicate a rich (too much fuel) condition. If the spark plug continually looks sooty or wet/oily it also would be a sign of a rich condition. If you have either of these problems, look for a dirty air filter first, and clean/re-oil as needed. Then if the filter was not dirty the carb may need to be serviced, and look for a sticking or damaged inlet needle or damaged float. Steve __________________ Current rides- 1981 Yami YZ250, 1993 Honda XR250L, 2003 Manco Hornet 50, 2015 Wolf W1, 2018 Wolf RX-50.
	0

02-11-2008, 09:06 PM	#14
Second-Lap-Motorsports Join Date: Feb 2008 Location: Owosso, MI Posts: 22	Where are you located? If you are close to Owosso, MI I would be willing to help you out for cheap. __________________ Current rides- 1981 Yami YZ250, 1993 Honda XR250L, 2003 Manco Hornet 50, 2015 Wolf W1, 2018 Wolf RX-50.
	0

02-09-2008, 04:16 AM	#2
pacman Join Date: Jan 2007 Posts: 36	Check the choke adjuster on the carb. It may not go all the way back. A lot of things will cause the engine to stutter. Fouled sparkplug. Dirty airfilter. misadjusted air/fuel ratio just to mention a few.
	0

02-09-2008, 05:40 PM	#5
bronevaya Join Date: Jun 2007 Posts: 162	well i changed the oil, put in some seafoam and changed the plug from the ngk to the one that came with the bike. the plug was sooty, but I dont know whats normal and whats not. the bike rode good, better then before, but I still felt tiny hesitation once. I will need to ride it further I guess to see if its completely gone.
	0

02-09-2008, 06:37 PM	#6
bronevaya Join Date: Jun 2007 Posts: 162	update: damn, still there, whats the damn deal :( :( :(
	0

02-09-2008, 08:09 PM	#7
MATT Join Date: Nov 2007 Posts: 83	from what I've heard a few people on this form have had success changing the plug cap.
	0

02-10-2008, 02:27 AM	#9
pacman Join Date: Jan 2007 Posts: 36	Did you check the choke? If the spark plug is sooty, your choke may be stuck.
	0

02-10-2008, 11:37 AM	#10
Suprsignet Join Date: Jan 2008 Posts: 88	I agree that it sounds like your bike is running a little rich. If the choke adjustment doesn't help, you can adjust the air/fuel mixture. It is asy to do, but if it is your first time playing with a carb, you should have someone help you just so things don't get too out of whack.
	0

02-10-2008, 04:14 PM	#11
bronevaya Join Date: Jun 2007 Posts: 162	well how should i go about adjusting it?
	0

02-11-2008, 12:07 AM	#12
Suprsignet Join Date: Jan 2008 Posts: 88	If you look at your bik's carb thre will be 2 brass screws. One is for adjusting th idle and one is for adjusting the air fuel mixture. The one with the spring on it is the idle screw. The small one with no spring is the air fuel screw. When adjusting the a/f mix make sure to refrence where you start with a sharpie or something (as this is your first time) and only back the screw off or turn it in 1 quarter turn max at a time. Turn the screw and then test ride the bike. Backing the screw out makes the bike leaner and turning it in makes the bike richer. From the sound of your problem and spark plug state it sounds like your engine is running rich. If you have never done this before take your time and only make small adjustments.
	0

02-11-2008, 04:17 PM	#13
bronevaya Join Date: Jun 2007 Posts: 162	I tried adjusting it to no avail, I am about to give up and take it to a shop :x
	0

02-11-2008, 09:37 PM	#15
Lifanrider Join Date: Feb 2008 Posts: 96	okay folks I read in another thread that turning the mixture screw counterclockwise enriches the mixture, here I read that it leans the mixture. Could someone please provide clarity on the this issue? thx. __________________ 2007 Lifan GY-5
	0