Lean or Rich?

[xaple]

I have noticed an overall lack of performance in my bike from some time now and i decided to do something about it.

My current setup:
-2009 Ninja 250 with 9500 miles
-Fresh-ish oil and semi new spark plugs. changed around 7-8k miles
-AreaP full exhaust system
-Snorkel removal from air-box
-DynoJet Stage 2 Jet Kit with #98 Main jets, Stock Pilot Jet, 2 1/2 Turns on idle screw, 2 Washers under needle with clip on 3rd notch
(I Have jets 94-100, 104-108)

The symptoms of lean or rich conditions I have are:

-Black on the inside of exhaust end pipe
-Slow and poor acceleration(if i rev to something like 6k and try to take off, it will drop back down close to idle then start moving)
-General power decrease throughout entire power-band, except maybe 2nd and 3rd high rpm.
-What seems to be poor gas mileage. Not thoroughly tested just a hunch
-Idle seems to be poor, fluctuates a little even when warm

I'm not sure if i am lean or rich. I'm leaning towards rich because of the inside of my exhaust being black.

I have not tried to run taking out the air filter because that doesn't seem smart.

I'm thinking of getting the K&N-0990 Pod filter and removing the air-box to offset the richness.
Ideas?

[Motofool]

What the plugs have to say?

http://www.dansmc.com/spark_plugs/sp...s_catalog.html

Clean air filter?

[xaple]

I'll take a look at the plug and snap some pics when it stops raining. i'm pretty sure my air filter is clean, for how old it is. that's why im thinking of getting a kn

[Motofool]

If it was carburating properly before, two things may have happened:

1) Increasing obstruction of air intake (mix becomes progressively rich).

2) Increasing obstruction of fuel flow (mix becomes progressively lean).

If plugs have been installed for some miles, let's say around 300~500 miles, they serve as a thermometer of the combustion.

[xaple]

It has been this way since I installed the exhaust way back, I just let it go. So the change occured once i installed a new exhaust, put in bigger jets, and removed snorkel.

[Motofool]

I see.

I cannot help beyond this point, since I am not familiar with these modifications.

I believe that the new jets have more influence on your problem than the new exhaust and that the air filter may the bottle neck for the flow in this case; but I don't really know enough to help you here.

Other members, like @choneofakind and @Jiggles may show up soon with real good advise.

[xaple]

Thanks for the help, once i can get a pic of the spark plug I'll link your name

[quarterliter]

Did you change heat range with the plugs? How old is the gas in the tank?

[xaple]

I fill up about every 2 weeks. Not sure what you mean by heat range, is that the gap?

[Motofool]

Originally Posted by xaple

.........Not sure what you mean by heat range.........

http://en.wikipedia.org/wiki/Spark_plug#Heat_range

http://faq.ninja250.org/wiki/Changin...rands_to_avoid

http://www.ninjette.org/wiki/Lean_or_Rich

[choneofakind]

First:
Your Ninja 250 will always have black soot in the end of the exhaust can because there's no cats in the exhaust, and the carbs just dump fuel in. That's just how it works. Unless the black build up is excessive, that's not an indicator of being rich.

Couple questions:
-Has the bike sat for any length of time greater than 2-3 weeks?
0Have any of these performance modifications been made recently? If so, was the bike acting like this before the modifications?
0Your idle fluctuation; is it cyclic up and down in a repeated method or is the hot idle just a different speed than the cold idle?

[quarterliter]

What is stock main jets for this bike? 98 seems small with an exhuast and snorkel removal.

[quarterliter]

What plugs did you put in it?

[choneofakind]

98 is the stock main on the new gen. 105 is the stock main on the pregen.
NOTE: I'm talking about Keihin/Factory pro sizes.

A 98 DJ is roughly equivalent to a Keihin 100. See here: http://www.ninjette.org/forums/showthread.php?t=10208 From my experience with these bikes, that should be roughly right for a full exhaust and no snorkel.

However, OP says the high rpm WOT stuff is good. That leads me to think that the main jets are the proper size. I'm betting on on needle height, but I need to ask some more questions once the OP answers my first questions.

[quarterliter]

Wouldnt it be lean if you put an exhuast system on and remove snorkel just a thought. Or maybe the pilot is too small. Just some ideas

[choneofakind]

Not necessarily. Remember he went up from a 98 K to a 100 K main jet. On a stock bike, the 98 K mains are actually pretty rich. Once you add a full exhaust and pull the snorkel, it's pretty much optimal, if not just a touch less rich than it should be (you want to aim for 12.8-13.2 under heavy load)

Since he went up a size, he should be fine.

When I added a full exhaust and opened my intake lid, I went up one size and it felt perfect. Another newgen rider around me took his bike to my shop and had them install a Yoshi full system and remove the snorkel and put in a high flow filter. They went up to a 100 K main. (same size as the OP is using). I'm pretty sure that his main is either right or close enough to be fine, even if he is at sea level. I'm not that much higher than sea level to really make a significant difference.

[xaple]

Stepped out for food about to head back to answer questions

[xaple]

Originally Posted by choneofakind

First:
Couple questions:
-Has the bike sat for any length of time greater than 2-3 weeks?
0Have any of these performance modifications been made recently? If so, was the bike acting like this before the modifications?
0Your idle fluctuation; is it cyclic up and down in a repeated method or is the hot idle just a different speed than the cold idle?

-No it has not sat for longer than a day or two.
-No recent modifications, all were done 4 months ago, the prob;ems started at that time though. It ran fine before modifications
-The idle cycles up and down, when the bike is hot and warmed up you can hear the change in rpms while idleing

Originally Posted by quarterliter

What plugs did you put in it?

NGK CR8E

Originally Posted by choneofakind

98 is the stock main on the new gen. 105 is the stock main on the pregen.
NOTE: I'm talking about Keihin/Factory pro sizes.

A 98 DJ is roughly equivalent to a Keihin 100. See here: http://www.ninjette.org/forums/showthread.php?t=10208 From my experience with these bikes, that should be roughly right for a full exhaust and no snorkel.

However, OP says the high rpm WOT stuff is good. That leads me to think that the main jets are the proper size. I'm betting on on needle height, but I need to ask some more questions once the OP answers my first questions.

The WOT isn't necessarily good, its not terrible but its lacking power for sure.

[choneofakind]

Originally Posted by xaple

-The idle cycles up and down, when the bike is hot and warmed up you can hear the change in rpms while idling

This is not a big issue. Sync the carbs.
http://faq.ninja250.org/wiki/How_do_...-bottle_method

Originally Posted by xaple

The WOT isn't necessarily good, its not terrible but its lacking power for sure.

Does it feel soggy? Does it feel like it's surging a bit? Does it feel flat? Does it hesitate before pulling?

First part is finding the right main jet.

[xaple]

Originally Posted by choneofakind

Does it feel soggy? Does it feel like it's surging a bit? Does it feel flat? Does it hesitate before pulling?

First part is finding the right main jet.

It feels like if i twist the throttle all the way open it lags behind a bit, like if i turn the throttle it doesn't respond immediately and i should be going faster. It definitely hesitate whens accelerating whether its WOT or at 3k rpm.

[xaple]

Here are pics of my spark plugs they look pretty ok, Whats the worse that can happen if the gap is too large or too small? @Motofool

[choneofakind]

Try the DJ 96. OEM air filter right?

Plug checks are really only valid if the engine is cut exactly where the fuel delivery is in question. That being said, those don't look like they've been under any long term abuse. Maybe a bit rich, but nothing bad.


EDIT: if you don't want to change jets, try going for a ride at night when it's cooler and see if the top end is better or worse. Better means your main jets are a bit big. Worse means the main jets are a bit small.

[xaple]

Originally Posted by choneofakind

Try the DJ 96. OEM air filter right?

Plug checks are really only valid if the engine is cut exactly where the fuel delivery is in question. That being said, those don't look like they've been under any long term abuse. Maybe a bit rich, but nothing bad.


EDIT: if you don't want to change jets, try going for a ride at night when it's cooler and see if the top end is better or worse. Better means your main jets are a bit big. Worse means the main jets are a bit small.

OEM filter is right, I'll drop down a size in jets. Would it be wise to get a better quality filter? I was thinking about the K&N pod filter to get rid of the air box since i always hate taking out the carbs.

[kbryant]

Originally Posted by xaple

I have noticed an overall lack of performance in my bike from some time now and i decided to do something about it.

My current setup:
-2009 Ninja 250 with 9500 miles
-Fresh-ish oil and semi new spark plugs. changed around 7-8k miles
-AreaP full exhaust system
-Snorkel removal from air-box
-DynoJet Stage 2 Jet Kit with #98 Main jets, Stock Pilot Jet, 2 1/2 Turns on idle screw, 2 Washers under needle with clip on 3rd notch
(I Have jets 94-100, 104-108)

The symptoms of lean or rich conditions I have are:

-Black on the inside of exhaust end pipe
-Slow and poor acceleration(if i rev to something like 6k and try to take off, it will drop back down close to idle then start moving)
-General power decrease throughout entire power-band, except maybe 2nd and 3rd high rpm.
-What seems to be poor gas mileage. Not thoroughly tested just a hunch
-Idle seems to be poor, fluctuates a little even when warm

I'm not sure if i am lean or rich. I'm leaning towards rich because of the inside of my exhaust being black.

I have not tried to run taking out the air filter because that doesn't seem smart.

I'm thinking of getting the K&N-0990 Pod filter and removing the air-box to offset the richness.
Ideas?

A few things - in South Florida conditions - hot humid - it would not be surprising at all to see it running on the rich side of things. Try going down on the main jet to a 96 and see if it improves.

Also, you note that you have "2 Washers under needle with clip on 3rd notch" No washers go under the clip. You are in affect raising the needle way too much, which would cause a very rich condition. The washers go above the clip. So if indeed you have installed them like that, correct that first before changing the main jet to a 96. This may very well be your issue.

[choneofakind]

If you want. I'm not a huge fan of the pod filters. They sound great. But they're loud.

They definitely will make taking the carbs out much easier.

EDIT: I didn't catch that. Kerry's right.

[xaple]

Originally Posted by choneofakind

EDIT: I didn't catch that. Kerry's right.

Originally Posted by kbryant

A few things - in South Florida conditions - hot humid - it would not be surprising at all to see it running on the rich side of things. Try going down on the main jet to a 96 and see if it improves.

Also, you note that you have "2 Washers under needle with clip on 3rd notch" No washers go under the clip. You are in affect raising the needle way too much, which would cause a very rich condition. The washers go above the clip. So if indeed you have installed them like that, correct that first before changing the main jet to a 96. This may very well be your issue.

My mistake, the washer are in fact above the clip, like the diagram in the jet kit shows. Looks like going down a jet size should help out.

Not sure if you remember but i was the kid who will called the full stainless steel system in lake worth when you were down here, called you a few times when i put the system on and my bike wouldn't idle because I accidentally turned the knob on the side that adjusts idle?

[xaple]

Originally Posted by choneofakind

If you want. I'm not a huge fan of the pod filters. They sound great. But they're loud.

They definitely will make taking the carbs out much easier.

EDIT: I didn't catch that. Kerry's right.

Loud as in louder than the short can?

[choneofakind]

Louder as in I have a Muzzy full system and the pod is louder than that. I find it annoying. Some people like it.


But Kerry still brought up a good question. Are you confusing needle height response with main jet top end pull? When you're judging the main jet, just focus on how smoothly and powerfully the bike reacts under WOT at high rpm's. How it acts as you're rolling on is not the main jet.

[xaple]

Originally Posted by choneofakind

Louder as in I have a Muzzy full system and the pod is louder than that. I find it annoying. Some people like it.


But Kerry still brought up a good question. Are you confusing needle height response with main jet top end pull? When you're judging the main jet, just focus on how smoothly and powerfully the bike reacts under WOT at high rpm's. How it acts as you're rolling on is not the main jet.

Ill take a look at my needles and check if anything is wrong, this is what they should be

[DaBlue1]

Originally Posted by xaple

....I'm thinking of getting the K&N-0990 Pod filter and removing the air-box to offset the richness.
Ideas?

Getting pods won't offset the richness. You will end up putting in even bigger jets and being even richer. You be testing more than riding.

Originally Posted by xaple

It feels like if i twist the throttle all the way open it lags behind a bit, like if i turn the throttle it doesn't respond immediately and i should be going faster. It definitely hesitate whens accelerating whether its WOT or at 3k rpm.

There can be a slight lag in the CV carb when you wack on the throttle. How does it react when you roll on the throttle?

Originally Posted by xaple

....OEM filter is right, I'll drop down a size in jets. Would it be wise to get a better quality filter?

You may want to add a little more air to mix. Get yourself something that breaths a little better. Less headaches.
WIX- P/N: 49721
UNI Air Filter- P/N: NU-2303 or
Pipercross Performance Air Filter- P/N: MXP166 (highly recommended),

[xaple]

Originally Posted by DaBlue1

Getting pods won't offset the richness. You will end up putting in even bigger jets and being even richer. You be testing more than riding.

I wanted the pods because it will make taking out carbs easier. I done it around 7 times already in the past 6 months and its a pain being my only mode of transportation i have to get it back together quick.

Originally Posted by DaBlue1

There can be a slight lag in the CV carb when you wack on the throttle. How does it react when you roll on the throttle?

Rolling on the throttle is a little smoother, not too much hesitation but again i feel like i should be going faster than i do.

Originally Posted by DaBlue1

You may want to add a little more air to mix. Get yourself something that breaths a little better. Less headaches.
WIX- P/N: 49721
UNI Air Filter- P/N: NU-2303 or
Pipercross Performance Air Filter- P/N: MXP166 (highly recommended),

I can't find that pipercross filter anywhere, when i search the only thing that came up is ninja 250 threads, nowhere to buy.

@kbryant @choneofakind I just put in the 96 Jets ill be able to test it out tomorrow to see how it worked

[xaple]

Side note, what is this? fell from somewhere when i was unscrewing the screw from the carb-engine header on the right side of the bike near the coolant reservoir. Its a hollow plaster like screw with a cap looking top, has notches around the side like a grip and the end has a jagged piece of plastic like it could have snapped off something

[kbryant]

Originally Posted by xaple

Not sure if you remember but i was the kid who will called the full stainless steel system in lake worth when you were down here, called you a few times when i put the system on and my bike wouldn't idle because I accidentally turned the knob on the side that adjusts idle?

Ah ok. I do remember you (and also the "idle" issue)
Don't be afraid to experiment. I have seen bikes respond well to DJ94 mj in South Florida conditions.

[DaBlue1]

Originally Posted by xaple

....I can't find that pipercross filter anywhere, when i search the only thing that came up is ninja 250 threads, nowhere to buy.

http://www.solomotoparts.com/Pipercr...or-250R-08-10/
http://stores.sportbiketrackgear.com/Detail.bok?no=9426
http://www.podiumsuperbike.com/store...idProduct=1118

[DaBlue1]

Originally Posted by xaple

.... i feel like i should be going faster than i do.

And you can....

Still running stock gears? If so, you need to change them. Extra HP means nothing if you don't take advantage of the power with proper gearing.

A 15 tooth front sprocket will gain you approx 4 mph on top end and lower your rpm speed by about 500 rpms. 15/43 is a good combo. Will add about 10 mph on the top end and lower your rpms speed by 1000 rpms.

[xaple]

Originally Posted by kbryant

Ah ok. I do remember you (and also the "idle" issue)
Don't be afraid to experiment. I have seen bikes respond well to DJ94 mj in South Florida conditions.

Will do thanks!

Originally Posted by DaBlue1

http://www.solomotoparts.com/Pipercr...or-250R-08-10/
http://stores.sportbiketrackgear.com/Detail.bok?no=9426
http://www.podiumsuperbike.com/store...idProduct=1118

Will one of these filters allow for the same amount of air movement as a pod filter?

Originally Posted by DaBlue1

And you can....

Still running stock gears? If so, you need to change them. Extra HP means nothing if you don't take advantage of the power with proper gearing.

A 15 tooth front sprocket will gain you approx 4 mph on top end and lower your rpm speed by about 500 rpms. 15/43 is a good combo. Will add about 10 mph on the top end and lower your rpms speed by 1000 rpms.

Will it make it faster off the line or just faster top end? I never max out my speed but I do like to get up and go faster.

[DaBlue1]

Originally Posted by xaple

.....Will one of these filters allow for the same amount of air movement as a pod filter?

No. The Pipercross (MX-166) is a high flow replacement for the stock filter (a flat panel). Pods flow more air.
See close up pics of the Pipercross Filter.

Originally Posted by xaple

....Will it make it faster off the line or just faster top end? I never max out my speed but I do like to get up and go faster.

It's not going to make your bike a 600, but you will notice a difference in how you shift. You will stay in a gear a little longer giving you more speed ( in other words you won't shift as quick). If you want to get up and go...twist the throttle a little more, but don't wack it wide open like you've been doing.

[xaple]

Originally Posted by DaBlue1

No. The Pipercross (MX-166) is a high flow replacement for the stock filter (a flat panel). Pods flow more air.
See close up pics of the Pipercross Filter.




It's not going to make your bike a 600, but you will notice a difference in how you shift. You will stay in a gear a little longer giving you more speed ( in other words you won't shift as quick). If you want to get up and go...twist the throttle a little more, but don't wack it wide open like you've been doing.

I don't really ever WOT I hardly ever go above 9k rpm. I don't want to make the wrong decision buying a new filter.

[DaBlue1]

Originally Posted by xaple

..... I don't want to make the wrong decision buying a new filter.

That's understandable. Here's some interesting info on the airbox.

[xaple]

Originally Posted by DaBlue1

That's understandable. Here's some interesting info on the airbox.

Going to leave the airbox in and go with the filter you recommended, should i keep the snorkel in? I saw alot of people saying the snorkel should be kept in.