Proper way to warm up motorcycle?

Question

I have a Ninja 250 that I bought in July. To start it up, I normally use minimum choke to get the bike started and let it warm up for about 5 minutes. I then drive a few blocks before closing the choke.

Normally this has worked just fine but lately my bike shuts off at the first couple of lights.

Half of my friends tell me that I shouldn't let the bike idle when I first start it and that I should not wait longer than a minute. Then other friends are telling me that I should let the bike warm up for about 5-10 minutes.

I'm so confused! What is the proper way to start the bike? What exactly does choke do and why is it bad to use it?

Answer 1

Twisting the throttle before you try starting only works if your carbs have accellerator pumps. My '79 Kawasaki does, but most new bikes have constant velocity carbs that normally don't have accellerator pumps. Some chokes restrict the air flow which pulls in more fuel. Other bikes, like my '79 don't have that sort of choke. Instead it uses an enriching circuit. The fellow with the 500 Ninja described his bike as reving up after starting and it being necessary to close the choke to reduce the speed. That behavior is typical of carbs with the enriching jets. With the traditional type of choke, the faster you rev the engine with the choke closed, the richer it runs. With the enrichment jet, the faster you rev it, the leaner it runs. With them, you can have the choke partially closed and it will run fine at higher speeds, but slow down at a stop sign and the engine will die from an overly rich mixture. Me, I use just enough choke and just long enough to keep it running ok and get going. Using too much choke will cause the excess gasoline to wash the oil off the cylinder walls and increase engine wear. If your bike misses or "blubs" before it dies, that's a sign of too much choke.

Answer 2

it is not 'bad' to use the choke. it makes the air/fuel mix richer and it is necessary to start a cold engine. (an electronically controlled fuel injected bike or car will make the mix rich automatically during a cold start.. since your bike has carbs and no electronic fuel control you have to make the mix rich at start up yourself with the choke

I own a Ninja 500 with a similar choke setup that is on your bike, and here is the procedure I use. It works for me when I ride in fall weather in the northeast (I ride down to high 30F weather) so it should work for you too

1) if it is a cold morning (less than 50F) then I open the choke fully when starting the bike. In warm weather the bike will start with the choke closed with a little bit of throttle

2) after the engine starts I leave the choke full open for a few seconds and let the bike idle. As the bike warms up the revs will start to climb. I close the choke partway so that the bike idles at around 1750rpm. personally, i do not let the engine rev much past 2000rpm when it is cold. I don't think it is good for the engine.

3) after a little bit you will notice that the coolant temp gauge will start to move. when the coolant needle starts to move i close the choke. I find that i need to roll on the throttle at little bit when i close the choke to keep the bike from stalling out. so at this point, the bike is idling with the choke fully closed. i will not touch the choke level again for the rest of the ride.

4) I usually wait until the coolant temp needle is close to the middle on the gauge before driving off. This is because it takes oil longer to reach operating temp than the coolant, and i want to make sure the oil is warm and flowing well before i rev the bike up.

I think it is a bad idea to ride the bike around with the choke open. if the choke is open the bike isn't warmed up, if it isn't warmed up, why are you riding it around?! also, with the choke open the engine is running very rich and this could cause the plugs to foul.

Answer 3

1. Read owner's guide that came with motorcycle.
2. Follow instructions.

Or you can get advice from know-nothings like me. I live in California. I have a Yamaha Virago 700. I use the choke only in winter, in the morning. As soon as the motorcycle is running, I push the choke back in. I let the motorcycle idle for 15 seconds (that's right, seconds). Then I put it in gear and go.

Don't idle your bike for long periods while choked. You'll foul your spark plugs. You need to pull your plugs out, clean them, and check the gap, make sure they're properly gapped.

If your motorcycle is dying like that, you should also check that the air filter(s) are reasonably clean.

Answer 4

Before starting, twist the throttle once or twice to get gas flowing. If your bike won't kick over after the first few revolutions, then open the choke about half way and try again. If it still won't start then open all the way. Once it's started, you should close it down to half way for about 30-60 seconds and then shut off completely. You can hand throttle it to keep it from dying. A couple of minutes of warm up and you should be ready to go. You're running too rich for too long and it will foul your spark plugs by leaving the choke open.

Answer 5

I agre with the poster above. Now it gets colder, I start with full choke (do not use the accelerator). As soon as it idles to high revolutions, I back the choke off to have it idle calmly for half a minute or so, so the oil gets through the engine. Also I let go of the clutch then (in neutral), to have the gears spin and warm up the cold transmission oil. Then, as you drive away, back off the choke more and more (squeeze the clutch, close the accelerator, then if the idle revs are getting quite high you know you can back off the choke some more). After a few minutes (2 - 5) the engine should be warm enough and you can completely back off the choke.

It is not bad to use the choke, it helps the engine start and warm up. However, it increases your gas useage so you do not want to use it more than necessary.

In warm weather, you do not need as much choke as in the winter. In cold weather, you need more choke (than minimal) to start and also the engine takes longer to warm up.

Answer 6

I somewhat agree with the first poster.

What he said about the description of the choke circuit on your Ninja 250. Allow the engine to run for 10-30 seconds and start to back the choke off. Allowing you bike to warm up does a few things. Number one; all the metal parts in the engine have a chance to expand back to a normal fitment state. Maybe you can envision this; someone comes to you while you are in a deep sleep and while waking you, tells you to start running down the block. Just not right, huh? Since you are on your bike, if you try to accelerate while the engine is cold, it may not respond and die or hesitate, causing you a potentially dangerous situation.
Take notice the next time you start your bike cold, if you have the choke set to on, and the bike wants to die and not fast idle, see if there is a trace of black smoke from the exhaust. If you notice this, it is too rich and the choke should be shut off earlier. Remember, it's just an aid to enrich your mixture and to enable the engine to start when cold. My next guess that the weather is changing and your bike may need a bit more choke when starting and running for the first few minutes.
Always refer to M.O.M. (motorcycle operator's manual) for the factory recommendations on "cold start procedures.

Answer 7

There is no need to warm up an air cooled engine. The choke shuts off the air to the fuel system. It allows a richer mixture for cold start. The choke should be opened as soon as engine starts. If you are leaving it closed or partly closed you are supplying a rich mixture to the engine which is probably causing it to die. If you must keep choke partly closed to ride you need a carb adjustment.

Answer 8

Each bike has its own idiosyncrocites about warming up. However, no matter the bike use the choke as little as possible. Once it's warm enough to idle without the choke turn the choke off. You can still continue to let warm up at idle for awhile but turn that choke off as soon as possible.

Answer 9

There are as many answer to this as riders. Warm the chain by riding the bike for 15 minutes. Clean the chain with kerosene or WD-40. Remember that kerosene is flammable - use it outside. Wipe it clean. Spray on some sort of Chain Wax or Chain Lube made for O-ring chains. Be careful not to spray anything on your tire. Wipe it off gently to remove overspray. Yes, you want it between the links where the o-rings are. Let it set overnight. End of story.

Answer 10

You don't need to "warm up" the engine, but you should start it and let it idle for maybe 30 seconds to make sure the oil has circulated before riding it.