Choke and Revving

[eddyble]

Hi guys,

I'm from Australia and hence have a carbureted version of the ninja. From my understanding, it's detrimental to ride whilst the the choke is engaged and the warm up procedure (choke on) should be done prior to heading off. AFAIK choke enriches the fuel/air mixture which makes the engine rev higher (i'm sure there is much more to it, but those are the effects that i can see)

My question is that If i don't have the time to warm up my bike in the morning, can i slightly rev the engine when stopped to have it not stall? viz. Is there an actual distinction between revving and choke?

tl;dr
Is revving the same as having the choke on?

Thanks

Regards,

Ed

[EthioKnight]

I'm by no means an expert but I should think the two, functionally speaking, do the same thing i.e. increase engine speed (RPMs). But bear in mind that the choke is a system on it own and so is the throttle...both has separate wires/assembly (guessticulating here) but like I said, they both serve the same purpose. But you shouldn't really be worried about riding your bike with the choke still on, it won't hurt it. Look @ this http://faq.ninja250.org/wiki/Warming_up_your_engine I daresay it will solve your worries.
Hope I helped.
Peace.

[CynicalC]

Choke and idle are two different things. It won't take more than a couple minutes to warm up while riding. You could have the choke on and gradually reduce it as you ride. Should only take a few blocks.

[Jiggles]

What I do is turn the choke on and let it warm for about 30seconds to a minute. Then I take off with the choke on and turn it off while riding. If there is a red light or I know I will have to stop I turn the choke back on and stop.

[Boom King]

Originally Posted by eddyble

AFAIK choke enriches the fuel/air mixture which makes the engine rev higher (i'm sure there is much more to it, but those are the effects that i can see)

The way I understand it, our choke is not a typical choke like you would find in a car. It is basically a fuel enrichment circuit or valve and when engaged, simply supplies more fuel. I could be wrong but I believe it only works when the throttle is closed. Start it up with the choke open and gradually close it once you notice that your RPMs are up when the bike is stationary, like when stopped at a light. It should not take more than a few minutes.

Wiki Carburetor Choke

Some carburetors do not have a choke but instead use a mixture enrichment circuit, or enrichener. Typically used on small engines, notably motorcycles, enricheners work by opening a secondary fuel circuit below the throttle valves. This circuit works exactly like the idle circuit, and when engaged it simply supplies extra fuel when the throttle is closed.

[Heed]

Why wouldn't you have time to warm up your bike? AFAIK, it takes 5 minutes at most.

[csmith12]

Originally Posted by CynicalC

Choke and idle are two different things. It won't take more than a couple minutes to warm up while riding. You could have the choke on and gradually reduce it as you ride. Should only take a few blocks.

^this... Just ride with the choke on. Turn it off after it's warmed up. Nothing to worry really about as long as it's not every day.

I like to give mine a min or two to get the oil circulating and warm up a bit while I put on helmet and gloves.

[etiainen]

Don't let it warm up idling, keep the choke on if necessary and take it easy until the bike is warmed up. Your bike will warm up much faster if you have a slight load on it, just don't start riding hard when the engine is cold. You can turn off the choke once the bike starts warming up.

I recently threw one of these onto my bike and I'm very happy with the temp gauge functionality(and having a clock)

http://www.ninjette.org/wiki/DIY_Day...ter_Temp_Gauge

Even when it's about 35-40 degrees F out, I only need the choke just for a little bit, and then take it easy until I get to operating temp. I have never waited 5 mins for warm up. I don't start my bike until all my gear is on and I'm ready to go.

[massacremasses]

you can let your engine warm up while its on its stand right?

Im serious for some reason I was thinking out couldnt... idk where I got that..

[DarC]

Pull choke, start, ride till warm, take off choke, enjoy.

Even my fuel injected bike has a fast idle circuit. I do like I did with the N250 and just pull it, start it (3rd times a charm), and let it idle for a few seconds while I put on my helmet and gloves and ride until the temp is 140ish then close the circuit.

The RC is the most tempermental (no pun intended )cold start bike I know of. It takes 3 blasts of the starter on cold days (just 1 when it's a bit warmer) and if it's below say 120-130ish degrees you have to make sure you give it plenty of throttle or the tall gearing will kill the motor before you know it when manuevering. All this and it historicall runs hot when it's warm outside, lol.

All this trouble but when she's warmed up and the tires are too it's nothing but bliss.

[eddyble]

I understand How the choke works and don't need any further clarification, i merely wanted to know if there was a distinction between revving and having the choke on, Not how to warm up my bike, which i have considerable expertise in (i mean, how can you not)

Thanks

ed

[DarC]

Comprehension fail! my bad, lol

I say no, there is not a difference. Either way you are adding an extra amount of fuel that makes the engine idle higher. No other wizardry at work here. The choke is only there so you can set it and forget it rather than manually holding the throttle open.....

And enrichener just adds a little more fuel, just like cracking the throttle.

[CynicalC]

Originally Posted by eddyble

I understand How the choke works and don't need any further clarification, i merely wanted to know if there was a distinction between revving and having the choke on, Not how to warm up my bike, which i have considerable expertise in (i mean, how can you not)

Thanks

ed

If you knew how the choke worked you would know the answer to your own question. No, revving by twisting the throttle is not the same as using the choke but IS the same as turning the idle adjustment knob on the left side of your bike.

[eddyble]

I need to phrase this in a more particular way it seems. I have an elementary understanding of the choke mechanism viz. it increases the fuel to air ratio and hence increases the rpm while idling.

Here we go, for the third time lol

choke on -> bike is now idling at 2000 rpm
Vs
Sustaining 2000 rpm via the throttle

Is there a marked difference? or is it the same thing.

[Jiggles]

I believe the temperature after combustion is different (lower on choke?) but I can't imagine that it makes a difference. Sometimes I will sit at a red light a rev my engine to keep it over 1000, othertimes I'll just have the choke idle at 3.5k

[CynicalC]

Originally Posted by eddyble

choke on -> bike is now idling at 2000 rpm
Vs
Sustaining 2000 rpm via the throttle

Is there a marked difference?

Yes.

[eddyble]

Originally Posted by CynicalC

Yes.

Would you care to elaborate good sir?

AFAIK, revving increases fuel supply to the carburetor which in turn feeds the engine and as a result rpms go up.

Choke from my understanding does exactly the same thing, as i did mention before, i am in no way a wrench monkey and have a very basic understanding (if any) of these systems so i would appreciate it if you could enlighten me in this regard

Thanks

Ed

[akima]

Originally Posted by eddyble

I need to phrase this in a more particular way it seems. I have an elementary understanding of the choke mechanism viz. it increases the fuel to air ratio and hence increases the rpm while idling.

Here we go, for the third time lol

choke on -> bike is now idling at 2000 rpm
Vs
Sustaining 2000 rpm via the throttle

Is there a marked difference? or is it the same thing.

I understood your question the first time and have been waiting for someone to answer

My bike doesn't have a manually operated choke, but I still want to know the answer to your question.

[CynicalC]

When an engine is cold, fuel doesn't ignite as easily as when it's hot. It tends to condense and get blown right through the exhaust unburnt. This is a lean condition. Using the choke enriches the mixture with more fuel to correct the imbalance. Whereas just twisting the throttle doesn't change the mixture, it just increases it. To put it very simply, twisting the throttle doesn't add fuel, it adds air. The carbs add fuel to compensate.

Now whether any of this matters is another story, but it doesn't make any sense to twist the throttle to keep a cold bike running when that's the sole purpose of the choke.

[eddyble]

Originally Posted by CynicalC

When an engine is cold, fuel doesn't ignite as easily as when it's hot. It tends to condense and get blown right through the exhaust unburnt. This is a lean condition. Using the choke enriches the mixture with more fuel to correct the imbalance. Whereas just twisting the throttle doesn't change the mixture, it just increases it. To put it very simply, twisting the throttle doesn't add fuel, it adds air. The carbs add fuel to compensate.

Now whether any of this matters is another story, but it doesn't make any sense to twist the throttle to keep a cold bike running when that's the sole purpose of the choke.

Thank you for this information as this will save me a substantial amount in regard to fuel costs

At the end of the day, (from your elaboration) the choke increases the ratio of fuel to air which effectively helps the engine warm up faster due to the fuels tendency to be inefficient when the engine is cold. Revving the engine will merely increase the output of fuel and due to the aforementioned issue, there will be increased fuel usage to ascertain the same effect. viz. warming the bike

So fundamentally speaking, both techniques (if you can call it that) warm the engine but the choke does it much more efficiently with less waste and considering i'm a student (a la Broke =[) it's much more economical to use the choke in comparison to revving. With this logic (given that the choke isn't left on once the engine is warm) there are no detrimental effects of having the choke on, if anything it's beneficial.

Thank you CynicalC for illuminating that for me

If there was a rep system, i would give you rep but i'm sure a smiley face will suffice

Ed

[CynicalC]

Actually, I can't say it would warm the bike up faster. If anything, it would warm up faster while running lean. It just helps the bike stay running properly while it's warming up. But it keeps your engine happy, and that will keep your wallet happy in the long run.

Also, I'm new to carbs myself so I can't say I understand them completely yet. But that's my story and I'm sticking to it until someone jumps in to correct me.

[eddyble]

Originally Posted by CynicalC

Actually, I can't say it would warm the bike up faster. If anything, it would warm up faster while running lean. It just helps the bike stay running properly while it's warming up. But it keeps your engine happy, and that will keep your wallet happy in the long run.

Hmn, that's rather counter intuitive as you did mention before that some fuel will go unspent and be wasted when the bike is cold (lean condition), so... less engine activity = hotter engine? my contention is that it would be the inverse :/ it's like saying less tyre revolutions = hotter tyres?

[CynicalC]

Nope a lean engine actually runs hotter than a rich one, as counterintuitive as it sounds.

[massacremasses]

in an internal combustion engine when you run lean the engine runs hotter than if it was running rich. Since (correct me if im wrong) the combustion of the gas and oxygen is more violent and creates more heat.

enriching the engine with the choke uses more gas to keep the same amount of it being burnt up and so it doesnt run lean. running lean is hard on any type of engine because of what I previously mentioned...

Someone chime in if I explained that right. Im new to carbs and motorcycles as well, but the whole rich and lean issue is not new at all to me as I have messed with cars for awhile now...

[CynicalC]

Originally Posted by massacremasses

in an internal combustion engine when you run lean the engine runs hotter than if it was running rich. Since (correct me if im wrong) the combustion of the gas and oxygen is more violent and creates more heat.

enriching the engine with the choke uses more gas to keep the same amount of it being burnt up and so it doesnt run lean. running lean is hard on any type of engine because of what I previously mentioned...

Someone chime in if I explained that right. Im new to carbs and motorcycles as well, but the whole rich and lean issue is not new at all to me as I have messed with cars for awhile now...

[nezumiamalek]

I typically start it w/ choke @ 75-80% then turn it up to 100% while its still on the stand. I heard it can clog your sparkplugs? 3-5 minutes idling w/ choke and I'm good to go. I'm typically putting on my equipment (helmet/glasses/gloves) during that process.

[Boom King]

Originally Posted by nezumiamalek

I typically start it w/ choke @ 75-80% then turn it up to 100% while its still on the stand. I heard it can clog your sparkplugs?

Maybe if you rode the bike 20 miles with the choke on you might get a bit of carbon fouling. For the 3 mins or so you have your choke on and then turn it off, once the plugs reach operating temps they will self-clean themselves to an extent.

[eddyble]

I find it incredibly strange that people keep answering the question i never asked....

[heylookitsfranco]

Originally Posted by eddyble

I find it incredibly strange that people keep answering the question i never asked....

lol. it's a somewhat informative thread nonetheless

[massacremasses]

your question was answered so I dont know what you are complaining about?

[etiainen]

That's how forums work:P

[CynicalC]

Originally Posted by massacremasses

your question was answered so I dont know what you are complaining about?

Give him a detailed answer and he can't comprehend it. Give him a one word answer and he asks for more details. Give him more details and he complains that we're helping him.

Hurrr

[eddyble]

haha, that's funny

I was commenting on the fact that people kept providing advice on how to warm up the bike instead of the question i initially posited. A man as smart as yourself should see that

thanks for the advice once again

ed

[heylookitsfranco]

Read your own post, man. You asked about the difference between choke operation and throttle input with specific regard towards warming up your motorcycle.

[LoD575]

Originally Posted by eddyble

Hi guys,

I'm from Australia and hence have a carbureted version of the ninja. From my understanding, it's detrimental to ride whilst the the choke is engaged and the warm up procedure (choke on) should be done prior to heading off. AFAIK choke enriches the fuel/air mixture which makes the engine rev higher (i'm sure there is much more to it, but those are the effects that i can see)

My question is that If i don't have the time to warm up my bike in the morning, can i slightly rev the engine when stopped to have it not stall? viz. Is there an actual distinction between revving and choke?

tl;dr
Is revving the same as having the choke on?

Thanks
Regards,
Ed

Lets break this down.
Is it detrimental to ride while the the choke is engaged? No it's not.

AFAIK choke enriches the fuel/air mixture which makes the engine rev higher. This is correct. The choke adds additional fuel while keeping the amount of air the same.

My question is that If i don't have the time to warm up my bike in the morning, can i slightly rev the engine when stopped to have it not stall?
Yes, you can do this with the desired results being the same.

Is revving the same as having the choke on?
The difference here is by using the throttle more air is being delivered to the engine which normally adds more fuel causing the engine to rev higher but it might stutter/run rough when cold due to a possible lean condition.

Using the choke even slightly the engine still revs higher by adding more fuel while keeping amount of air the same eliminating the lean condition resulting in smoother operation of the engine until normal operating temperature is obtained.

Hopefully this answers your questions.

[TBC]

Originally Posted by LoD575

Lets break this down.

I don't know about the OP, but that sure cleared things up for me. Thanks!

[250rr]

How should I warm my bike?

[TBC]

Originally Posted by 250rr

How should I warm my bike?

I vote for mittens - they are by far the cutest option.

[akima]

+1

[Sailariel]

There is no right or wrong way in warming up the bike. You do what works for you.
My bike is garaged. I open the door, fire up the bike, and get my gear on. By that time the bike is ready to go. That works for me.

My new bike has FI. It still needs to be warmed up.

The 250R and the Honda NT-700 both have wet clutches. They work better with warm oil. You may notice that when the engine is cold, engaging first gear is usually accompanied with a clunk and sometimes a slight jerking motion forward. That becomes less evident if you use Synthetic Oil. I used Rotella T-6 in the Ninja and also use it in the Honda. It's good stuff and available everywhere.