Slow acceleration sleep after 40mph

[jackliu239]

I just got this 2006 Ninja 250, so far it only have less than 250 miles on it, I only rode for about 100 miles after the purchase, and this is my first motorcycle. One thing I notice recently is that I can accelerate the bike to 40 mph no problem around the 3-4 gear.

But going from 40mph to 50 is very very hard. Even after I twist the throttle all the way in around the 4th gear, the RPM still goes up very slowly from 6-8, I sometimes have to downshift 1 gears for the RPM to go up to 7-8, then up shift again, but even with all of this. So far I still have not gone more than 50 mph yet. I'm sure if I will eventually get it up to 60+ mph, but I feel like that is going to take a long time to happen.

I don't even want to think how can I ever go to freeways, it will take so long for me to accelerate to 60, I'll be a road hazard.

I am a new rider, so is this normal for 250? And does it have to do with the fact that the bike's engine is still in the break-in period?

Also another thing I notice but might be unrelated, after the RPM goes to more than 7, the sound the engine makes is a bit different, yes it's louder, but I feel like it's a bit more than that, I can't describe it, but the pitch of the sound is much higher as well as the noise level. So when I hear that I always shift gear, I'm afraid it will damage the engine or something.

[DaBlue1]

Other than ride it, what have you checked?
Have you checked the air filter?
What size sprockets are on the bike?
What condition are the spark plugs in?
At what RPM speed do you normally shift gears? 40-50 mph should be very easy to reach in 3rd or 4th gear.

[KawiKid860]

06 with 2500 miles could be gummed up carbs

[jackliu239]

Originally Posted by DaBlue1

Other than ride it, what have you checked?
Have you checked the air filter?
What size sprockets are on the bike?
What condition are the spark plugs in?
At what RPM speed do you normally shift gears? 40-50 mph should be very easy to reach in 3rd or 4th gear.

I have not check air filters, the sprocket are original factory size, I have check the spark plugs, they are good. I normally shift gears at 5-6.

[jackliu239]

Originally Posted by KawiKid860

06 with 2500 miles could be gummed up carbs

Sorry, that was a typo, it has less than 250, not 2500 miles on it.

[ninjamunky85]

Carbs probably need cleaned. Try shifting at 12k rpm's.

[nokfir2]

Originally Posted by jackliu239

Sorry, that was a typo, it has less than 250, not 2500 miles on it.

even worse.

that means it was ridden average 35 miles a year. this bike has done alot of sitting around. def clean those carbs...

also....ninja 250's arn't that fast anyway

[jackliu239]

Oh the carbs are completely cleaned, when I first got it the engine won't even start without cleaning the carbs.

I'm just curious around RPM do you guys shift? For me, it seems I always shift at around 5-6k RPM which is very easy to get for from 1-40 MPH, but after the 3rd or 4th gear after I shift, the RPM meter stays at 5-6k, and it takes a much longer time to go up to 7-8K as well as speed going up.

But I do get the feeling that I should shift the prior gears at much higher RPM and well as my current gear?

[jackliu239]

Originally Posted by nokfir2

even worse.

that means it was ridden average 35 miles a year. this bike has done alot of sitting around. def clean those carbs...

also....ninja 250's arn't that fast anyway

Well, not average of 35 miles a year... more like 100 miles during the first month, and 0 miles for the rest of the 6 years

[jackliu239]

For example, when I'm at 5th gear at around 4-5k RPM, no matter how much gas I give it, the speed won't increase at all.

This is normal right? Because I changed gear too early?

[KawiKid860]

You need to rev a 250. On bigger bikes those speeds+rpms are fine, but the 250 doesn't have anywhere near the power of something larger

[Motofool]

Originally Posted by DaBlue1

Have you checked the air filter?

This is very important.

After 7 years of storage that filter needs oil, ..........if that foam didn't disintegrate itself by now.

If the inbox is free, the next thing to check is any restriction to the supply of fuel.

[SDx]

I shift at around 8k when commuting and somewhere between 9k and 11k when out in the hills

[thisisbenji]

When I had my 250, I don't think I was ever below 5,000 not even when going slow. I'd shift typically around 8,000-9,000.

[quarterliter]

Make sure the bike is warm before your shifting at these high rpm. Touch the case on the right side. If it is too hot to hold your hand on it then your good to rev it. But stay under 5k when the bike is cold. Take a few warm up laps around the subdivision or something before having to go anywhere. Rotella 15w40 for a cheap good oil and a wix filter. Change it every 2000 miles tops. Its cheap easy and a good thing to do. Oil the airfilter and run ethanol free gas. I got my bike with 250 miles on it too. Carb cleaning and oil change etc later, it runs like a champ.

[jackliu239]

Thanks, great advice. Maybe just one more question, I find my bike is really slow to warm up, sometimes I need to open the choke partially for up to a few minutes otherwise the engine just shuts off on me. I assume this is because the engine is not hot enough right?

Or is my fuel tank have water inside of it? Because I left the bike at friend's place for 2 days, I found out that his sprinkler system turns on every morning for about 15 minutes and my bike is all wet because of it, I'm just afraid that there might be water drops gather at the top of the fuel tank and leaking inside. So is there anyway to check if you have water in your fuel tank?

[jackliu239]

Also during the warm up process, the engine won't start with full choke on, unless I give it a bit of gas to start.

What I have to do is that, press the start button, I would hear this put-put-put then it quickly dies out. UNLESS at the same time of starting the put-put-put I give it throttle then immediately the engine would start come online and jumps to about 4-5k RPM (I can let go of throttle and it still runs) it stays there until the engine fully warms up, (this is with choke on btw), but if I ever put off the choke in the process of warming up, the engine would dies right away.

I'm not worried about turning off choke and engine dies during warm up, I heard this is normal.

But is the other part normal? The one that immediate after the engine starts I have to give it gas to make it from dying out (once I give it gas to start, the engine can keep going with no problem).

With everything else being said, the bike runs excellent (I think).

[agentbad]

Try putting some seafoam in the gas tank and see if that helps the carbs. If it's warm out you shouldn't really need to use the choke.

[jkv45]

You're not going to go anywhere on a 250 Ninja if you don't rev it to where the power is. The older Pre Gen Ninjas need to be near 10,000 to really get rolling. There's not much power or torque available at 5000 or 6000.

Change the oil and filter if you haven't already, check the basic maintenance items, and let 'er rip. Don't hesitate to go to 10,000 or beyond if you need to (once it's at operating temp - as Quarterliter noted).

If you want a 250 that doesn't need to rev to that range you need to look at the CBR250R. The 250 single isn't a screamer like the Ninja's twin.

As long as you do the proper maintenance and use decent oil (and keep track of the oil level), the high revs aren't a problem.

Here's a comparison of 250 power curves. The Ninja curve is the later model than yours, and actually makes its power lower, but you can see why you need to spin pretty high to get to the power.

[DaBlue1]

Originally Posted by jackliu239

.... I find my bike is really slow to warm up, sometimes I need to open the choke partially for up to a few minutes otherwise the engine just shuts off on me. I assume this is because the engine is not hot enough right?

Originally Posted by jackliu239

....Also during the warm up process, the engine won't start with full choke on, unless I give it a bit of gas to start.

What I have to do is that, press the start button, I would hear this put-put-put then it quickly dies out. UNLESS at the same time of starting the put-put-put I give it throttle then immediately the engine would start come online and jumps to about 4-5k RPM (I can let go of throttle and it still runs) it stays there until the engine fully warms up, (this is with choke on btw), but if I ever put off the choke in the process of warming up, the engine would dies right away.

.

Sounds like your idle speed may be too low. Once the bike is fully warmed, set the idle speed @ 1500 rpms and see how it does. Also add some Star Tron Fuel Treatment and some fresh 87 octane gas to your tank.

[Chuffmonkey]

Originally Posted by jackliu239

But going from 40mph to 50 is very very hard. Even after I twist the throttle all the way in around the 4th gear, the RPM still goes up very slowly from 6-8, I sometimes have to downshift 1 gears for the RPM to go up to 7-8, then up shift again, but even with all of this. So far I still have not gone more than 50 mph yet. I'm sure if I will eventually get it up to 60+ mph, but I feel like that is going to take a long time to happen.

I'm not sure that your original question was answered definitively - this is not normal. This sounds nothing like an issue with you not being in the powerband, and everything like poor ignition.

Can you define slowly - how many seconds does it take to accelerate from 40 to 50?

If you're on the flat and go WOT there should be absolutely no need to have to downshift to accelerate - my (admittedly newgen) Ninja had enough pull in top gear to get me from 40 to 50 without requiring a downshift.

As was mentioned you need to check airflow, spark and fueling - any of these can cause a power loss.

As for needing the choke to start, my Ninja always needed the choke, no matter what the ambient temperature was - and I often had to give it gas right away. I would treat these as 2 separate issues and worry about the poor acceleration first - but again, please define "slowly" for us.

[crazymadbastard]

I believe that your choke is messed up, I had the same issue but with a boat and it was the choke not opening.Take a look at the choke cable and its operation. If the choke is on at high speed, the motor is getting too much fuel.

[jackliu239]

Originally Posted by Chuffmonkey

I'm not sure that your original question was answered definitively - this is not normal. This sounds nothing like an issue with you not being in the powerband, and everything like poor ignition.

Can you define slowly - how many seconds does it take to accelerate from 40 to 50?

If you're on the flat and go WOT there should be absolutely no need to have to downshift to accelerate - my (admittedly newgen) Ninja had enough pull in top gear to get me from 40 to 50 without requiring a downshift.

As was mentioned you need to check airflow, spark and fueling - any of these can cause a power loss.

As for needing the choke to start, my Ninja always needed the choke, no matter what the ambient temperature was - and I often had to give it gas right away. I would treat these as 2 separate issues and worry about the poor acceleration first - but again, please define "slowly" for us.

I think the slow acceleration is my driving problem, I was at 4th or 5th gear at 4-5k rpm and it won't go fast no matter how much gas I give it, but today, I tried to shift only at near 6-7k RPM and I see some very big improvements. So far I have not yet gone faster than 50 mph yet, and I think if I only shift around 7k rpm it shouldn't be a problem.

What I am more concerned is potential water in my fuel tank, my bike was soaked from my friend's water sprinkler system. Does anyone know if Ninja's fueling port have some kind of seal? Preventing water from leaking inside when it's fully closed?

[jackliu239]

Originally Posted by crazymadbastard

I believe that your choke is messed up, I had the same issue but with a boat and it was the choke not opening.Take a look at the choke cable and its operation. If the choke is on at high speed, the motor is getting too much fuel.

Would be, when I try to cold start, it will only start with choke all the way on, and I have to give it a bit of gas from engine dying out, and once the engine starts with full choke on, it immediately jumps to 5-6k RPM.

I need to keep this for at least 1 minute, during this 1 minute, any lowering of the choke will kill the engine, but after 1 minutes or a bit more, I can try to lower the choke a bit and it might go down to 4k rpm, but if I'm not carefully, if I accidentally lower the choke too much the engine dies as well.

[jackliu239]

Originally Posted by DaBlue1

Sounds like your idle speed may be too low. Once the bike is fully warmed, set the idle speed @ 1500 rpms and see how it does. Also add some Star Tron Fuel Treatment and some fresh 87 octane gas to your tank.

Once the bike is fully warmed and in operation, the idle speed is actually just around 1.5k RPM. The bike runs great after 10 minutes or so, it's just the first few minutes gets my all worried every time I start it up.

[jackliu239]

Originally Posted by jkv45

You're not going to go anywhere on a 250 Ninja if you don't rev it to where the power is. The older Pre Gen Ninjas need to be near 10,000 to really get rolling. There's not much power or torque available at 5000 or 6000.

Change the oil and filter if you haven't already, check the basic maintenance items, and let 'er rip. Don't hesitate to go to 10,000 or beyond if you need to (once it's at operating temp - as Quarterliter noted).

If you want a 250 that doesn't need to rev to that range you need to look at the CBR250R. The 250 single isn't a screamer like the Ninja's twin.

As long as you do the proper maintenance and use decent oil (and keep track of the oil level), the high revs aren't a problem.

Here's a comparison of 250 power curves. The Ninja curve is the later model than yours, and actually makes its power lower, but you can see why you need to spin pretty high to get to the power.

Thanks for the tip, I didn't know that. This is my first motorcycle, when I drove my car I never let the RPM go more than 3k acceleration or starting. Everything was so smooth lol, I'm just afraid that rev the engine too hard will make my Ninja explode, but I know now this is not the case.

[n4mwd]

When you cleaned your carbs, did you clean the pilot jets as well? A lot of people miss those.

Here is what normal acceleration on an unmodified Ninja 250 is like:

Link to original page on YouTube.

FYI: If you lean forward, you can avoid accidental wheelies.

[Motofool]

Originally Posted by jackliu239

.......when I try to cold start, it will only start with choke all the way on, and I have to give it a bit of gas from engine dying out, and once the engine starts with full choke on, it immediately jumps to 5-6k RPM...........

Those high rpm are hurting your cold engine.

Lubricate your choke mechanism and cable to be able to fine adjust the rpms' at start up never higher than 3K.

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

What about that neglected poor air filter?

[quarterliter]

immediatly jumps to 5-6k

[ninjamunky85]

That's what it will do with the choke fully on.

[jackliu239]

Originally Posted by Motofool

Those high rpm are hurting your cold engine.

Lubricate your choke mechanism and cable to be able to fine adjust the rpms' at start up never higher than 3K.

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

What about that neglected poor air filter?

Thanks, that's good advice, I'll check air filer as well as choke line.

I'll try the best method to perfecting my warm up process. I got to say, motorcycles requires A LOT more hands on attention than my SUV lol. So is all carbrated bike like this? Are fuel injection bikes like CBR250 don't need to warm up?

[jkv45]

Originally Posted by jackliu239

Are fuel injection bikes like CBR250 don't need to warm up?

They don't need any input from the rider during warm-up. The F.I. system reads the engine temp, air temp, etc and enrichens the mixture just enough to maintain a slightly high idle for only as long as necessary.

The choke isn't that big of a deal. Once you get it figured out you won't think about it.

[n4mwd]

The choke control is touchy, but you can get it to idle at 3K RPM with a little practice.

Nevertheless, it still sounds like your carbs aren't right.

[jackliu239]

The carb has been stripped and clean to the very last detail, includes the jets.

I may have figure out the problem, when I open the seat cover, I can see 3 rubber tube supplying oxygen going to the crab (I think), one of the tube is bend in the middle, for example, have you ever tried to wash your car at your own drive way, then suddenly the water flow stops or became very slow, then you figure out that the hose rubber tube is twisted onto it self and water flow became a problem. It is exactly like that for one rubber line, and there is no way to straighten it, because I think it has been bend for so long, the rubber has became fatigue and permanently bend out of shape.

[The_big_dill]

There are two very good points that have been previously mentioned, and until you check them, you are not going to be able to diagnose the problem correctly.

1. Is your Air Filter clean?

2. Did you clean the pilot jet when you cleaned the carbs?

- These are hard to get to and pretty much invisible when installed.

Edit, you replied as i was typing this message

[The_big_dill]

Originally Posted by jackliu239

The carb has been stripped and clean to the very last detail, includes the jets.

I may have figure out the problem, when I open the seat cover, I can see 3 rubber tube supplying oxygen going to the crab (I think), one of the tube is bend in the middle, for example, have you ever tried to wash your car at your own drive way, then suddenly the water flow stops or became very slow, then you figure out that the hose rubber tube is twisted onto it self and water flow became a problem. It is exactly like that for one rubber line, and there is no way to straighten it, because I think it has been bend for so long, the rubber has became fatigue and permanently bend out of shape.

Which hose is it? Can you take a picture?

[DaBlue1]

Originally Posted by jackliu239

.... I can see 3 rubber tube supplying oxygen going to the crab (I think), one of the tube is bend in the middle,

You may be referring to CA. Emission hoses on the tank. Instead of venting the tank directly to the air, gas fumes are contained in a closed system (if it's still installed on the bike.)



The middle hose is just a vent hose and connects to nothing. The hoses on the left and right connect to a canister.

[jackliu239]

Originally Posted by DaBlue1

You may be referring to CA. Emission hoses on the tank. Instead of venting the tank directly to the air, gas fumes are contained in a closed system (if it's still installed on the bike.)



The middle hose is just a vent hose and connects to nothing. The hoses on the left and right connect to a canister.

It is the far right one, the previous owner must have lock it under the seating locking mechanism and put it like that for many years, now the hose is permanently bend somewhere in the middle. Do you know what does that hose connect to?

[jackliu239]

Originally Posted by The_big_dill

There are two very good points that have been previously mentioned, and until you check them, you are not going to be able to diagnose the problem correctly.

1. Is your Air Filter clean?

2. Did you clean the pilot jet when you cleaned the carbs?

- These are hard to get to and pretty much invisible when installed.

Edit, you replied as i was typing this message

I don't know if the filter is clear or not, I took it out and it looks clean enough, I even use my vacuum machine to vacuum on it a bit as well as use my compressor to blow air on it quite a bit, some dust come off it, but not that much.

Both pilot jet was clogged, they have to use the needle and wire to clean it very carefully, now it's cleaned, before it was not cleaned the bike won't even start at all.

At this point I have to wait until tomorrow to start the bike to see any difference, because I want it to cool down to the air temperature first, I will also see if there is anything I can do to the hose to strengthen it a bit.

[n4mwd]

This might help a little:



But it doesn't look like any of this stuff would interfere with the engine that bad. It connects to the overflow line of the carb and another spot connects to the airbox. There is nothing standing out that would actually interfere with the running of the bike that I can see.