So how does choke work?

ericeng91 · April 13th, 2011, 05:12 PM

So with the 250r being carbed, I'm kind of confused on how to use the choke and what the terminology is.

Such as, when starting the bike, do I open the choke or close the choke? Or somewhere inbetween.

And same for when I start riding. How do I know what is the right amount and on the 250r, what position is what? (all the way up is open/closed... etc.)

And any other tips on chokes? I know the basic idea of the choke is to control the amount of airflow going into the engine to get it to run richer or leaner. And this effects how the gas burns in some way... But I really don't understand it.

Sorry if this is a repeated question, if there is a thread on this already please link me over. I didn't see anything when I tried searching. Or maybe I just didn't search enough.

kkim · April 13th, 2011, 05:16 PM

http://faq.ninja250.org/wiki/What_is..._at_startup%3F

http://faq.ninja250.org/wiki/How_a_c...Morning_Coffee

ericeng91 · April 13th, 2011, 07:34 PM

thanks kkim, i can't believe I missed that. Those links answered my questions perfectly.

kkim · April 13th, 2011, 07:38 PM

I would advise anyone to go there and read every topic listed in the wiki. a wealth of information that each ninja 250 owner should be familiar with.

mj23retired · April 13th, 2011, 11:44 PM

ok so now i am confused. my bike always starts perfectly fine without opening the choke. however, if i were to just turn it on and jump on the bike, it doesnt run smoothly if that makes sense. if i give it throttle immediately after starting, it sputters a bit. i was told by a buddy of mine with a 250 that he turns the bike on with the choke off, and then lets it idle for a bit with the choke maybe around half until the bike is running smoothly. the wiki that kkim linked to doesn't seem to explain it this way. am i wrong or is this a case of whatever works for my particular bike?

kkim · April 14th, 2011, 12:33 AM

higher ambient temps would require less choke to start when the engine is cold. I see you're in AZ. Could it be that you're average yearly temps are quite high, requiring or negating the use of the choke? also, has your bike seen any jetting changes?

I typically flip the choke lever to about halfway, push the start button w/o touching the throttle and the bike will lumber to life and then start climbing in revs to about 3K. I dial back the choke lever so the bike idles at about 2-2.5K. I gradually turn down the choke lever as the revs tries to keep climbing from that 2.5K mark. After a few minutes, the choke can be turned off and my bike will idle at the preset 1500rpm.

mj23retired · April 14th, 2011, 08:24 AM

ok so while i may not need to choke to physically start the bike, i will still want to flip it about halfway and gradually turn it down as you mention, allowing the bike to idle for a few minutes

mrlmd · April 14th, 2011, 08:46 AM

Read the owners manual. These bikes are "coldblooded" and need the choke to start first thing in the morning. Put it on 1/2 way, no throttle, start it. If it's running at high idle, simply turn it down a little, no big deal. Let it run for 15-30 sec., drive off and slowly and turn it down as it warms up. Why is this so hard, why is there such a macho thing to start the bike without the choke and have it run like crap 'till it warms up?

Nemesis · April 14th, 2011, 09:35 AM

Thread title was very misleading!

mj23retired · April 14th, 2011, 09:08 PM

no macho thing here. i am just trying to learn from everything here, and this is actually a question i have had for a while and been meaning to ask. i didn't realize it was suggested to actually ride with the choke on for a while.

mrlmd · April 15th, 2011, 06:50 AM

While it's called a "choke", it actually does not restrict the air intake, like in an older style car carb with butterfly valves on it, to enrich the gas/air mixture. It is an "enricher circuit" that puts in more gas to accomplish the same thing, keeping the air intake unchanged.

Does this make sense to you? You are accomplishing the same end result by two different means.

And it is perfectly fine to ride with the choke on for a while as the engine warms up.

April 13th, 2011, 05:12 PM	#1
ericeng91 ninjette.org member Name: Eric Location: Maryland (BWI) Join Date: Apr 2011 Motorcycle(s): Soon to be Ninja 250r Posts: 25	So how does choke work? (solved, close please!) So with the 250r being carbed, I'm kind of confused on how to use the choke and what the terminology is. Such as, when starting the bike, do I open the choke or close the choke? Or somewhere inbetween. And same for when I start riding. How do I know what is the right amount and on the 250r, what position is what? (all the way up is open/closed... etc.) And any other tips on chokes? I know the basic idea of the choke is to control the amount of airflow going into the engine to get it to run richer or leaner. And this effects how the gas burns in some way... But I really don't understand it. Sorry if this is a repeated question, if there is a thread on this already please link me over. I didn't see anything when I tried searching. Or maybe I just didn't search enough. Last futzed with by ericeng91; April 13th, 2011 at 07:34 PM.

April 14th, 2011, 08:46 AM	#8
mrlmd ninjette.org sage Name: Marc Location: Crawfordville, Florida Join Date: Jan 2010 Motorcycle(s): 2005 Suzuki S50, 2006 Kawasaki Ninja EX250F, 1990 Honda PC800, 2000 Yamaha TW200 Posts: 848	Read the owners manual. These bikes are "coldblooded" and need the choke to start first thing in the morning. Put it on 1/2 way, no throttle, start it. If it's running at high idle, simply turn it down a little, no big deal. Let it run for 15-30 sec., drive off and slowly and turn it down as it warms up. Why is this so hard, why is there such a macho thing to start the bike without the choke and have it run like crap 'till it warms up? Last futzed with by mrlmd; April 14th, 2011 at 01:35 PM.

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April 13th, 2011, 05:16 PM	#2
kkim Join Date: Nov 2008 Posts: Too much.	http://faq.ninja250.org/wiki/What_is..._at_startup%3F http://faq.ninja250.org/wiki/How_a_c...Morning_Coffee

April 13th, 2011, 07:34 PM	#3
ericeng91 ninjette.org member Name: Eric Location: Maryland (BWI) Join Date: Apr 2011 Motorcycle(s): Soon to be Ninja 250r Posts: 25	thanks kkim, i can't believe I missed that. Those links answered my questions perfectly.

April 13th, 2011, 07:38 PM	#4
kkim Join Date: Nov 2008 Posts: Too much.	I would advise anyone to go there and read every topic listed in the wiki. a wealth of information that each ninja 250 owner should be familiar with.

April 13th, 2011, 11:44 PM	#5
mj23retired ninjette.org member Name: Ernie Location: Tempe, AZ Join Date: Feb 2011 Motorcycle(s): green 2010 ninja 250r Posts: 35	ok so now i am confused. my bike always starts perfectly fine without opening the choke. however, if i were to just turn it on and jump on the bike, it doesnt run smoothly if that makes sense. if i give it throttle immediately after starting, it sputters a bit. i was told by a buddy of mine with a 250 that he turns the bike on with the choke off, and then lets it idle for a bit with the choke maybe around half until the bike is running smoothly. the wiki that kkim linked to doesn't seem to explain it this way. am i wrong or is this a case of whatever works for my particular bike?

April 14th, 2011, 12:33 AM	#6
kkim Join Date: Nov 2008 Posts: Too much.	higher ambient temps would require less choke to start when the engine is cold. I see you're in AZ. Could it be that you're average yearly temps are quite high, requiring or negating the use of the choke? also, has your bike seen any jetting changes? I typically flip the choke lever to about halfway, push the start button w/o touching the throttle and the bike will lumber to life and then start climbing in revs to about 3K. I dial back the choke lever so the bike idles at about 2-2.5K. I gradually turn down the choke lever as the revs tries to keep climbing from that 2.5K mark. After a few minutes, the choke can be turned off and my bike will idle at the preset 1500rpm.

April 14th, 2011, 08:24 AM	#7
mj23retired ninjette.org member Name: Ernie Location: Tempe, AZ Join Date: Feb 2011 Motorcycle(s): green 2010 ninja 250r Posts: 35	ok so while i may not need to choke to physically start the bike, i will still want to flip it about halfway and gradually turn it down as you mention, allowing the bike to idle for a few minutes

April 14th, 2011, 09:35 AM	#9
Nemesis CVMA #74 WSMC #750 Name: Nemesis Location: On the track Join Date: Oct 2009 Motorcycle(s): All of them Posts: A lot.	Thread title was very misleading!

April 14th, 2011, 09:08 PM	#10
mj23retired ninjette.org member Name: Ernie Location: Tempe, AZ Join Date: Feb 2011 Motorcycle(s): green 2010 ninja 250r Posts: 35	no macho thing here. i am just trying to learn from everything here, and this is actually a question i have had for a while and been meaning to ask. i didn't realize it was suggested to actually ride with the choke on for a while.

April 15th, 2011, 06:50 AM	#11
mrlmd ninjette.org sage Name: Marc Location: Crawfordville, Florida Join Date: Jan 2010 Motorcycle(s): 2005 Suzuki S50, 2006 Kawasaki Ninja EX250F, 1990 Honda PC800, 2000 Yamaha TW200 Posts: 848	While it's called a "choke", it actually does not restrict the air intake, like in an older style car carb with butterfly valves on it, to enrich the gas/air mixture. It is an "enricher circuit" that puts in more gas to accomplish the same thing, keeping the air intake unchanged. Does this make sense to you? You are accomplishing the same end result by two different means. And it is perfectly fine to ride with the choke on for a while as the engine warms up.