Hesitating: is the only answer a jet kit?

SFRider23 · April 26th, 2010, 07:59 PM

Okay so I bought my 2008 Ninja 250r used and already installed on it is a Two Brothers exhaust. I noticed it was doing a lot of hesitating when accelerating in the lower gears. I would use the throttle and it would literally hesitate/ignore my action, then it would almost sputter, then get like a burst and then take off. It was really a big problem because I would be trying to accelerate up a hill, avoid a car, or in traffic and it would not react when I need it to.

So... I took it in for a 5,000 mile tune-up and told them about it. The tech guy said it had to do with the aftermarket exhaust and my carbs not being adjusted for the exhaust. He gave me options; 1. they would adjust the carbs and chances are that it will help the issue, but no guarantee or 2. have a jet kit installed and that would absolutely fix it but cost $200 more (parts and labor). I opted for the carb adjustment to save the money.

After the adjustment I will say it is not as bad, but really it is still a problem. If I start my bike up about 10 minutes before I want to go somewhere then it will be fine and dandy... but if I don't, then I will definitely deal with the same hesitating problem.

Any advice for me?

caliente103 · April 26th, 2010, 08:04 PM

you need a jet kit http://www.ninjette.org/forums/showthread.php?t=10208

Alex · April 26th, 2010, 08:38 PM

It's not a good idea to have the bike sitting there for 10 minutes before you ride off. Once it's running smoothly, just start riding. In the bay area, that means about 15 seconds of warmup.

Yes, it is a good idea to be careful with any stops/starts/sharp turns during warmup, just in case the engine doesn't respond exactly how you'd want.

kkim · April 26th, 2010, 08:52 PM

Quote:

Originally Posted by SFRider23

1. they would adjust the carbs and chances are that it will help the issue, but no guarantee

what exactly did they do?

gogoKawi · April 26th, 2010, 08:59 PM

I have the same problem. Since I moved up north, the bike hasn't been as responsive. I think he just doesn't like the cold weather... But, I have an HMF slip-on and was recommended to do a rejet. I probably will in the next couple of weeks. The lag has been down right terrible.

SFRider23 · April 26th, 2010, 09:02 PM

Sounds like I need a jet kit then huh?

kkim, I honestly don't really know what they did. He said something about the carbs performing for the market exhaust and when an aftermarket exhaust is put on that the carbs need adjusting so it performs correctly... or something like that. It's been a good month, so I forgot exactly what his explaination was. I don't know enough about bikes, so I just assumed he knew what he was talking about. Anyway... it didn't fix the problem.

NorCal_250R · April 26th, 2010, 10:28 PM

He didn't do anything with your carbs...probably just cleaned them.
The stock fueling sucks...the main jet is way too rich, the needles are all wrong, and the pilot jets work better as 40s than the stock 38s...

Get the Factory Pro jet kit or Sportisi one.
Get the air filter from Sportisi...
Replace your front springs with the correct ones for your weight and put in 15w oil.

Love the bike after all that is done...it will be fantastic...

kkim · April 26th, 2010, 10:30 PM

shim the carb needles w/ 3 washers and remove the airbox snorkel. if the shop readjusted the mixture screws, they will need to be adjusted again. you should find out from them exactly what was done so you will know how to proceed.

lots of info on the forum to answer any questions you may have on how to do this.

ninja250 · April 27th, 2010, 10:03 AM

Quote:

Originally Posted by kkim

shim the carb needles w/ 3 washers and remove the airbox snorkel. if the shop readjusted the mixture screws, they will need to be adjusted again. you should find out from them exactly what was done so you will know how to proceed.

+1

Shim that sucker. Couple washers from the hardware store. Check the DIY.
Will feel like a whole new bike.

SFRider23 · April 27th, 2010, 05:31 PM

Thanks everyone...

I went back to the shop today and asked the desk guy what they did to "adjust the carbs", he went and asked the tech that worked on it and came back to say that he made the pilot jet more rich.

Now I don't know much about bikes... I'm a new rider so I'm just now getting into it. So what now? Now that we know he made the pilot more rich, what is my next plan of attack? I've heard a couple of suggestions:

Get the Factory Pro jet kit or Sportisi one.
Get the air filter from Sportisi...
Replace your front springs with the correct ones for your weight and put in 15w oil.

and

shim the carb needles w/ 3 washers and remove the airbox snorkel

Hmmmm.... both of those options sound like I would need someone to do it for me. What is cost differences for those two options? Am I going to get the same result with either option?

THanks again everyone, keep the advice coming!

I sure need it.
-Sandy

kkim · April 27th, 2010, 06:10 PM

Sandy,

Sounds like they readjusted the mixture screws. If you are going to pay for labor for someone to work on the bike, I would suggest just having them install a jet kit. Factory Pro or Dyno Jet are reputable/proven kits.

Have the snorkel removed and a free flowing filter installed at the same time.

I suggested shimming the needles cause if you do it yourself, it costs pennies for the parts.

Good luck... I'm sure you'll love the bike once the work has been completed.

SFRider23 · April 28th, 2010, 10:02 PM

KKim, thanks so much... quick question though, what will the snorkel removal and free flowing filter do for the bike/ride? And how much time/labor time would I be adding to do this?

Thanks!

kkim · April 28th, 2010, 10:17 PM

http://www.ninjette.org/forums/showthread.php?t=10090

Removing the snorkel and installing a free flowing air filter will maximize the amount of air the bike is able to ingest with the stock airbox. This, in conjunction with the slip on you presently have, will enable the engine to breathe/process air/fuel a lot better.

The jet kit, once properly installed, with optimize the extra air the bike is now able to process, making more power.

The peak horsepower will be raised by a few, but the real dividend in doing all of this will be the bike's power should be smoother/fatter from idle to redline, resulting in an easier to ride bike.

If you are using a shop to install the jet kit, it would be crucial for them to test the jetting on a dyno for maximum gain. Short of that, be sure they understand if they install the the jet kit and you're not happy with the results, they will fine tune the jetting for you at no additional cost in the future. I they balk at that, find a shop that does dyno work to install the jet kit and test.

Personally, I would suggest you and a mechanically inclined friend install the jet kit so you can learn what's involved, so you can work on your own bike in the future.

Anyone can install a jet kit... it's the fine tuning (every bike is different as to what it takes to be optimum) that really makes the bike come alive.

April 26th, 2010, 07:59 PM	#1
SFRider23 ninjette.org newbie Name: Sandy Location: San Francisco, CA Join Date: Mar 2010 Motorcycle(s): 2008 Ninja 250R Posts: 6	Hesitating: is the only answer a jet kit? Okay so I bought my 2008 Ninja 250r used and already installed on it is a Two Brothers exhaust. I noticed it was doing a lot of hesitating when accelerating in the lower gears. I would use the throttle and it would literally hesitate/ignore my action, then it would almost sputter, then get like a burst and then take off. It was really a big problem because I would be trying to accelerate up a hill, avoid a car, or in traffic and it would not react when I need it to. So... I took it in for a 5,000 mile tune-up and told them about it. The tech guy said it had to do with the aftermarket exhaust and my carbs not being adjusted for the exhaust. He gave me options; 1. they would adjust the carbs and chances are that it will help the issue, but no guarantee or 2. have a jet kit installed and that would absolutely fix it but cost $200 more (parts and labor). I opted for the carb adjustment to save the money. After the adjustment I will say it is not as bad, but really it is still a problem. If I start my bike up about 10 minutes before I want to go somewhere then it will be fine and dandy... but if I don't, then I will definitely deal with the same hesitating problem. Any advice for me?

April 26th, 2010, 08:04 PM	#2
caliente103 ninjette.org member Name: HECTOR Location: Bronx NY Join Date: Oct 2009 Motorcycle(s): Red 08 250r Posts: 218	you need a jet kit http://www.ninjette.org/forums/showthread.php?t=10208 __________________________________________________ http://www.nycsportbikeriders.com/ Jetkit,15/43,HID Last futzed with by caliente103; April 27th, 2010 at 04:05 AM.

April 26th, 2010, 08:38 PM	#3
Alex ninjette.org dude Name: 1 guess :-) Location: SF Bay Area Join Date: Jun 2008 Motorcycle(s): '13 Ninja 300 (white, the fastest color!), '13 R1200RT, '14 CRF250L, '12 TT-R125LE Posts: Too much. Blog Entries: 7	It's not a good idea to have the bike sitting there for 10 minutes before you ride off. Once it's running smoothly, just start riding. In the bay area, that means about 15 seconds of warmup. Yes, it is a good idea to be careful with any stops/starts/sharp turns during warmup, just in case the engine doesn't respond exactly how you'd want. __________________________________________________ Montgomery Street Motorcycle Club / cal24.com / crf250l.org / ninjette.org ninjette.org Terms of Service Shopping for motorcycle parts or equipment? Come here first. The friendliest Ninja 250R/300/400 forum on the internet! (especially Unregistered)

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
08+ Jet Kit	Donnyd21	Motorcycle-related	2	October 25th, 2014 09:26 PM
jet kit	james250ninja	1986 - 2007 Ninja 250R Tech Talk	5	October 8th, 2013 05:32 AM
WTB- Tool kit, R-0990, jet kit	jman511115	Items Wanted	3	July 17th, 2012 01:44 PM
jet kit	greatwhiteninja	Motorcycle-related	0	July 8th, 2011 08:12 PM
08-09 250r jet kit and hid kit for sale	09250r	Motorcycle-related	7	September 10th, 2009 03:41 PM

April 26th, 2010, 08:59 PM	#5
gogoKawi ninjette.org sage Name: Dre Location: DMV Join Date: Aug 2009 Motorcycle(s): 2014 Ninja 300, 2008 ZX6, 2011 Ninja 1000 Posts: 622	I have the same problem. Since I moved up north, the bike hasn't been as responsive. I think he just doesn't like the cold weather... But, I have an HMF slip-on and was recommended to do a rejet. I probably will in the next couple of weeks. The lag has been down right terrible.

April 26th, 2010, 09:02 PM	#6
SFRider23 ninjette.org newbie Name: Sandy Location: San Francisco, CA Join Date: Mar 2010 Motorcycle(s): 2008 Ninja 250R Posts: 6	Sounds like I need a jet kit then huh? kkim, I honestly don't really know what they did. He said something about the carbs performing for the market exhaust and when an aftermarket exhaust is put on that the carbs need adjusting so it performs correctly... or something like that. It's been a good month, so I forgot exactly what his explaination was. I don't know enough about bikes, so I just assumed he knew what he was talking about. Anyway... it didn't fix the problem.

April 26th, 2010, 10:28 PM	#7
NorCal_250R ninjette.org member Name: Jordan Location: Corte Madera Join Date: Jun 2009 Motorcycle(s): 06 Ninja 650R, 08 Ninja 250R, 00 Aprilia SR50 (dead) Posts: 94	He didn't do anything with your carbs...probably just cleaned them. The stock fueling sucks...the main jet is way too rich, the needles are all wrong, and the pilot jets work better as 40s than the stock 38s... Get the Factory Pro jet kit or Sportisi one. Get the air filter from Sportisi... Replace your front springs with the correct ones for your weight and put in 15w oil. Love the bike after all that is done...it will be fantastic...

April 26th, 2010, 10:30 PM	#8
kkim Join Date: Nov 2008 Posts: Too much.	shim the carb needles w/ 3 washers and remove the airbox snorkel. if the shop readjusted the mixture screws, they will need to be adjusted again. you should find out from them exactly what was done so you will know how to proceed. lots of info on the forum to answer any questions you may have on how to do this.

April 27th, 2010, 05:31 PM	#10
SFRider23 ninjette.org newbie Name: Sandy Location: San Francisco, CA Join Date: Mar 2010 Motorcycle(s): 2008 Ninja 250R Posts: 6	Thanks everyone... I went back to the shop today and asked the desk guy what they did to "adjust the carbs", he went and asked the tech that worked on it and came back to say that he made the pilot jet more rich. Now I don't know much about bikes... I'm a new rider so I'm just now getting into it. So what now? Now that we know he made the pilot more rich, what is my next plan of attack? I've heard a couple of suggestions: Get the Factory Pro jet kit or Sportisi one. Get the air filter from Sportisi... Replace your front springs with the correct ones for your weight and put in 15w oil. and shim the carb needles w/ 3 washers and remove the airbox snorkel Hmmmm.... both of those options sound like I would need someone to do it for me. What is cost differences for those two options? Am I going to get the same result with either option? THanks again everyone, keep the advice coming! I sure need it. -Sandy

April 27th, 2010, 06:10 PM	#11
kkim Join Date: Nov 2008 Posts: Too much.	Sandy, Sounds like they readjusted the mixture screws. If you are going to pay for labor for someone to work on the bike, I would suggest just having them install a jet kit. Factory Pro or Dyno Jet are reputable/proven kits. Have the snorkel removed and a free flowing filter installed at the same time. I suggested shimming the needles cause if you do it yourself, it costs pennies for the parts. Good luck... I'm sure you'll love the bike once the work has been completed.

April 28th, 2010, 10:02 PM	#12
SFRider23 ninjette.org newbie Name: Sandy Location: San Francisco, CA Join Date: Mar 2010 Motorcycle(s): 2008 Ninja 250R Posts: 6	KKim, thanks so much... quick question though, what will the snorkel removal and free flowing filter do for the bike/ride? And how much time/labor time would I be adding to do this? Thanks!

April 28th, 2010, 10:17 PM	#13
kkim Join Date: Nov 2008 Posts: Too much.	http://www.ninjette.org/forums/showthread.php?t=10090 Removing the snorkel and installing a free flowing air filter will maximize the amount of air the bike is able to ingest with the stock airbox. This, in conjunction with the slip on you presently have, will enable the engine to breathe/process air/fuel a lot better. The jet kit, once properly installed, with optimize the extra air the bike is now able to process, making more power. The peak horsepower will be raised by a few, but the real dividend in doing all of this will be the bike's power should be smoother/fatter from idle to redline, resulting in an easier to ride bike. If you are using a shop to install the jet kit, it would be crucial for them to test the jetting on a dyno for maximum gain. Short of that, be sure they understand if they install the the jet kit and you're not happy with the results, they will fine tune the jetting for you at no additional cost in the future. I they balk at that, find a shop that does dyno work to install the jet kit and test. Personally, I would suggest you and a mechanically inclined friend install the jet kit so you can learn what's involved, so you can work on your own bike in the future. Anyone can install a jet kit... it's the fine tuning (every bike is different as to what it takes to be optimum) that really makes the bike come alive.