1st Gear, Low RPM Troubles

[jhunter]

Greetings. I've been reading around on several forms, Google-returned websites, etc. on an issue I'm having with my bike, and I've pretty much narrowed it down to being a carb-related issue and I was hoping to get some feedback about whether or not I'm on the right track, and how to possibly address the issue.

I decided to get a 250 ninja for my learning bike and even though I was originally going to go for one of the older models, I had an opportunity to pick up a '08 for relatively cheap due to needing some minor mechanical work and a majority of the fairings replaced due to it being laid down previously. I figured that this offered me the chance to learn the mechanics of the bike while also not having to worrying about trashing the thing since the fairings were already messed up anyways.

When the bike was restored to the point where it was working and drivable, I installed a K&N air filter (the original air filter was no where to be found) and that was pretty much the only non-stock thing done to it. Well, that and the firewall thing in the airbox was removed. Forgot to put it back in the airbox before everything was closed back up, and it seemed like too much of a hassle to take everything apart again to install it.

Regardless, the bike is acting a little goofy. It is having a lot of difficulty in 1st gear, particularly in the sub-5k RPM range. If you barely turn the throttle you can slowly, though somewhat adequately (unless haste is necessary), get the bike moving. If you put the throttle down, say, half way, it will sputter and hop between power and nothing. This actually caused me to lay the bike down earlier today, though it's probably more dumb luck that it hadn't done so before that. Finally, if you just torque the throttle down all the way, it drops down to 1k RPM and while I haven't made it stall out, I wouldn't be surprised if it did.

Once you get the bike moving, and it gets above 5-6k RPM in 1st gear, or just out of 1st gear all together, it accelerates fine. I question whether it's running optimally at higher gears and speeds, but my lack of experience in such things leaves me seeking advice from more seasoned individuals on this board.

What may be causing this issue, and what should I do about it?

From what I've read, it appears that I may need to rejet the carbs, but that seems a bit excessive for just putting in an air filter. But if that is the case, the following kit seemed like the best fit for the bike:

http://www.amazon.com/Factory-Pro-Co...dp/B002S4J32W/

In any case, if I could get some assistance from the members of this board, I would be most grateful. I put off taking care of this for about two weeks now, but after laying the bike down today I decided I needed to stop fooling around with it and actually fix the thing before I hurt myself.

Thanks in advance for any insights that may be provided.

[Skippii]

Air filters generally make a much bigger difference than exhaust, so rejetting isn't unreasonable. If you only have issues as low rpm, you need the full jet kit, just adjust the idle screws. If you don't have the same issues in gears other than 1st, jetting isn't the problem.
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[jhunter]

Hey Skippii, thanks for your help.

So to test if it's a rejet issue, I just need to put the bike into a higher gear and force it to try and run at that low rpm range. If it does the same thing in second and third gear, then that would qualify it as a jetting issue, in which case the link I provided would not be sufficient.

Did I understand everything you said correctly?

[PsHYk]

might just be running lean i guess from the air filter im not sure but seems like it might be that try what Skip said about adjusting the the idle screw if not check the carbs and make sure theyre not dirty or something or maybe something stopping the fuel from passing correctly im new too but from other stuff i read thats what i think... check it out though see whats up let us know what you find out...

[DaBlue1]

Originally Posted by jhunter

....the bike is acting a little goofy. It is having a lot of difficulty in 1st gear, particularly in the sub-5k RPM range. If you barely turn the throttle you can slowly, though somewhat adequately (unless haste is necessary), get the bike moving. If you put the throttle down, say, half way, it will sputter and hop between power and nothing. This actually caused me to lay the bike down earlier today, though it's probably more dumb luck that it hadn't done so before that. Finally, if you just torque the throttle down all the way, it drops down to 1k RPM and while I haven't made it stall out, I wouldn't be surprised if it did.

Once you get the bike moving, and it gets above 5-6k RPM in 1st gear, or just out of 1st gear all together, it accelerates fine. I question whether it's running optimally at higher gears and speeds,

What may be causing this issue, and what should I do about it?

Assuming the restoration was properly done and the carbs cleaned and adjusted properly as well, you may not have a carb problem. A simple change in filter (drop in type) will not significantly impact performance, however if you have removed the snorkel, you need to put it back in. The spark arrestor also can change the way the air flows through the intake and should be put back in for the stock configuration.

The Ninja 250 does not have a lot of power in the lower rpm (1/8 - 1/4 throttle range). If the bike starts on the choke, warms up and idles fine, chances are is that you need to hone your launch (take off skills). The Ninja likes higher rpm speed and hates being lugged around at lower rpms below 3k, even in 1st -3rd. When starting to move the bike after it's been warmed, try getting your rpm speed closer to 3k, then shift in the 6-8k range. About 5k is the start of the power range so you will feel the bike pull nicely. Don't wack open the throttle or it will lag a bit especially if the engine is cold. CV carbs operate on a vacuum and needs engine speed create the proper amount to move the slides open inside the carbs. You need to learn to gradually roll on the throttle when learning to ride. Proper clutch and throttle control are going to be essential to controlling the speed/power and manuevering the bike without getting into trouble. The Ninja is a very forgiving bike, so if you make a mistake in shifting or wrong throttle inputs it won't protest too much, but will still let you know by way of poor performance.

Also make sure that your idle speed is adjusted to approx 1300-1350 after the bike is properly warmed, by using the idle adjustment knob next to the fairing. If you are blipping (wacking open the throttle) when the engine is cold and the idle is set wrong the rpms can drop, but it should come back to it's set point. If it stalls, the bike may be too rich at that particular setting.

[jhunter]

Another thing I forgot to mention is that when it's sitting still it seems that there is a potent smell of gas.

I'll check the idle setting, I'm pretty sure it's not set at 1300.

[DaBlue1]

Originally Posted by jhunter

..... when it's sitting still it seems that there is a potent smell of gas.

Is the smell noticeable when the bike is running or when it's off?
Are you using the choke?
Is the smell closer to the tank or the end of the exhaust?
Any noticeable carb leaks?

[jhunter]

Got the idle at 1300 now.

Fuel smell is when it's running. A friend wanted to try out the bike so I left him do so on the lawn with fair warning of the throttle issue. When he stopped it, he commented on the fuel smell so I felt that my suspicions of that not being normal was somewhat supported.lol

It would seem concentrated more towards the exhaust. No carb leaks that I saw and I use the choke to crank it, but once it's running I tend to back it off.

[DaBlue1]

Originally Posted by jhunter

....Fuel smell is when it's running.

....It would seem concentrated more towards the exhaust.

Have you made or the previous owner made any adjustments to the carbs? Seems odd that the OEM filter was missing.

If the gas smell is coming from the exhaust you may be a little rich. You may need to find out from the PO if any changes were done to the carbs or check the carb settings yourself. Take the bike out for an extended ride at higher rpms then check to see if the bike still smells rich at other than low rpms.

[jhunter]

I think I got it fixed for the most part. Something had gotten in the space next to the snorkel and was blocking air flow. Sheesh.

Thanks for all the help!

[DaBlue1]

Originally Posted by jhunter

I think I got it fixed for the most part. Something had gotten in the space next to the snorkel and was blocking air flow. Sheesh.

Thanks for all the help!

That would have been the next thing to look at. So Why was the OEM filter missing?

[jhunter]

The bike was stolen and summarily wrecked before it was returned to the po. He had it stored at his brother-in-laws for a couple years and some pieces just got lost (it was broken down some because he was trying to fix it initially).

The purchase was just a good deal for both of us. I got him out from under the loan and I got a bike that I wanted, but also allowed me the opportunity to learn on. It's been a great learning process thus far.

[YamiLionheart]

Hey jhunter,

I've been experiencing the same issues on my 2009 250r that I bough used about a month or two ago. Seems to have difficulties getting going in first gear, almost as if the throttle isn't putting power to the engine and I have to quickly yank the clutch in to stop the bike from stalling after it already starts moving a little bit.

Just wanted to verify that the issue you found was some junk blocking the snorkel? Also what state were your air filters in? Do you think that could have something to do with this?

When I go home I'm going to check the snorkel to see if I also have something blocking it.

[csmith12]

Welcome Mike! Start an intro thread.

[vmax]

hi,

i think you don't need to rejet your bike, cause you bike have a problem only below 5k (not above). First thing, set your mixture screw to default 2,5 L, 1.75 R and see your idle. If your idle not good then set to 2,5 L, 2 R. Then test run your bike and if still problem, maybe your low end was to lean, the try shimming your needles. Hope this help you.

[jhunter]

Originally Posted by YamiLionheart

Hey jhunter,

I've been experiencing the same issues on my 2009 250r that I bough used about a month or two ago. Seems to have difficulties getting going in first gear, almost as if the throttle isn't putting power to the engine and I have to quickly yank the clutch in to stop the bike from stalling after it already starts moving a little bit.

Just wanted to verify that the issue you found was some junk blocking the snorkel? Also what state were your air filters in? Do you think that could have something to do with this?

When I go home I'm going to check the snorkel to see if I also have something blocking it.

Hey Yami,

Yeah, my low power issue was primarily from a bag of stuff a friend had put in my storage area under the passenger seat falling down into the body area beside the snorkel. It caused the bike to randomly have very little power in the low end of first gear which was a little precarious at times (e.g. pulling out on a road ). Once it got into the upper RPM of first and into second it would perform alright, but it would run very rich and put out a fairly heavy scent of gas.

After I found the item blocking the area of the snorkel and removed it, the bike had a noticeable increase in overall performance. It was far more consistent and reliable than it was before. Go figure, right?heh

The filter was a brand new K&N filter with no dirt on it or anything. If your bike is running rich, I suppose I would check the airbox area first to make sure everything is clear and air can move freely through it. This would include the snorkel and also the filter. I think the filters do need to be cleaned from time to time, so it's always good to check it periodically.

As a side note: I later checked my spark plugs just for kicks and noticed that they were pretty burnt up from the previous owner of the motor (ran the thing pretty lean apparently). So I ended up replacing them as well. If you're unsure of the condition of your plugs and you're still having problems after checking the airbox area, it might be worth looking into.

Hope this helps.

[DaBlue1]

Originally Posted by YamiLionheart

....I've been experiencing the same issues on my 2009 250r that I bough used about a month or two ago. Seems to have difficulties getting going in first gear, almost as if the throttle isn't putting power to the engine and I have to quickly yank the clutch in to stop the bike from stalling after it already starts moving a little bit.

How long was your bike sitting before you purchased it and what condition is it in now?
Did the problems just start?
Does the bike run better on full choke?
Is the bike fully warm before trying to take off?
What is your idle speed when fully warmed?
Have you considered using a fuel treatment such as Star Tron or Stabil Ethanol Treatment (90+% of low speed running problems are attributed to dirty carbs)

Here are a few things that could possibly be wrong with yours;

Poor Running at Low Speed:

Fuel/air mixture incorrect:
Pilot screw maladjusted
Pilot jet, or air passage clogged
Air bleed pipe bleed holes clogged
Pilot passage clogged
Air cleaner clogged, poorly sealed, or element missing
Choke plunger stuck open
Fuel level in carburetor float bowl too high or too low
Fuel tank air vent obstructed
Carburetor holder loose
Air cleaner duct loose


Check the Troubleshooting Guide for other symptoms.
90+% of low speed running problems are attributed to dirty carbs.

[rocka81]

Originally Posted by jhunter

Regardless, the bike is acting a little goofy. It is having a lot of difficulty in 1st gear, particularly in the sub-5k RPM range. If you barely turn the throttle you can slowly, though somewhat adequately (unless haste is necessary), get the bike moving. If you put the throttle down, say, half way, it will sputter and hop between power and nothing. This actually caused me to lay the bike down earlier today, though it's probably more dumb luck that it hadn't done so before that. Finally, if you just torque the throttle down all the way, it drops down to 1k RPM and while I haven't made it stall out, I wouldn't be surprised if it did.

Sounds like carb's are getting too much fuel to me.

[YamiLionheart]

Originally Posted by csmith12

Welcome Mike! Start an intro thread.

Hey thanks man! I'll do that in a few

[YamiLionheart]

Originally Posted by jhunter

Hey Yami,

Yeah, my low power issue was primarily from a bag of stuff a friend had put in my storage area under the passenger seat falling down into the body area beside the snorkel. It caused the bike to randomly have very little power in the low end of first gear which was a little precarious at times (e.g. pulling out on a road ). Once it got into the upper RPM of first and into second it would perform alright, but it would run very rich and put out a fairly heavy scent of gas.

After I found the item blocking the area of the snorkel and removed it, the bike had a noticeable increase in overall performance. It was far more consistent and reliable than it was before. Go figure, right?heh

The filter was a brand new K&N filter with no dirt on it or anything. If your bike is running rich, I suppose I would check the airbox area first to make sure everything is clear and air can move freely through it. This would include the snorkel and also the filter. I think the filters do need to be cleaned from time to time, so it's always good to check it periodically.

As a side note: I later checked my spark plugs just for kicks and noticed that they were pretty burnt up from the previous owner of the motor (ran the thing pretty lean apparently). So I ended up replacing them as well. If you're unsure of the condition of your plugs and you're still having problems after checking the airbox area, it might be worth looking into.

Hope this helps.

Thanks for the response!

There are a lot of things that I still have to check on the bike before I can definitely blame it on this. The other night I rode it and had no problems at all, and all I did was turn the idle up a bit. (It was idling at around 1000-1100 previously, and it's cold on long island, around 30-40 degrees right now). Now it's idling around 1300. Not sure if that had anything to do with it, or if the problem is simply more sporadic.

Still have plenty of winter time to check everything on my days off so I just gotta take it day by day. Never the less, I love this damn thing haha. So glad I found one in blue, such a pretty little thing

[YamiLionheart]

Originally Posted by DaBlue1

How long was your bike sitting before you purchased it and what condition is it in now?
Did the problems just start?
Does the bike run better on full choke?
Is the bike fully warm before trying to take off?
What is your idle speed when fully warmed?
Have you considered using a fuel treatment such as Star Tron or Stabil Ethanol Treatment (90+% of low speed running problems are attributed to dirty carbs)

1. Bought the bike in November, the previous owner had ridden the bike during that season. I believe maybe just 2 weeks before I had purchased it. It was always garage kept, had 7100 miles on it.

I keep it in my garage now, and always let it warm up with the choke (cold here on long island right now so choke is necessary to get it to run) until it's warm enough to idle on it's own without any choke before I ride it.

2. Problems have seem to just started, I've only ridden the bike maybe 3 or 4 times since I still only have my permit, and the cold weather isn't super pleasant to ride in. The problem isn't something that happens every time though. It is sporadic. Last time I rode I had no problems with low end power in first, getting going, etc.

3. Assuming when you say run the bike you mean actually riding it around, I've never ridden the bike with the choke on, always let it warm up to where I don't need to have the choke on while riding, so I can't say if it rides better with the choke on. Once it's warmed up, If I put the choke on it will idle right up to around 5k.

4. Yes. Always let it warm all the way up (assuming that once the bike idles at it's normal speed without any choke assistance means that it is fully warmed up).

5. Recently adjusted the idle screw since it's very cold here right now. Last time when I had the problems it was idling around 1100. I read that was a little bit low, and adjusted the screw when the bike was warmed up, it now idles around 1300.

6. Haven't thought into the issue that much, but I will read about those and consider them.

I'm off today so if I get a chance I'll play around on my blue baby a bit and see how she's feeling. Temps where I am might get up into the low 50's today which would be the warmest I've ridden it in so far. I'll let you know how it feels.

Thanks a ton for the questions and suggestions Blue, I appreciate it!

[himynameisjoe]

Just so you know, warming up your bike is bad. Choke her and ride. Just slowly reduce the choke in your ride until she's warm. Only takes like 5 minutes. Even in 20 degree weather!