|Topic Review (Newest First)|
|07-29-2014 09:09 AM|
|Clownin||Yes, that worked. Thank you. Also at the bottom of the review is a review for the 2008 250. :-)|
|07-29-2014 08:56 AM|
Ok, here is a link to a very informative 3rd party article in motorcycle.com with some good reasons why you should consider jetting your bike, that is if you are looking for optimum performance? It talks specifically about a 2010 ninja and specifically about the dynojet kit, it's fuel needles and jets etc.
Hope it helps.
|07-29-2014 06:44 AM|
Ok, I have an '08 250. The manual that, I found under the seat, stated the bike is an EX250J. I still have not read through it completely. Since the 18th of July, this is what I have currently done to the bike: new oil mobile 1 4T race Syn 10w-40, new K&N high flow oil filter, new K&N high flow cotton air filter, Danmoto JISU slip on exhaust and last NGK Iridium spark plugs(yesterday) + almost 1100 miles haha. Before I had done anything to the bike the snorkel was already off and the bike idled smooth, at 1500 when warmed up. when I changed oil + filter and air filter, the bike started idling around 1800-1900 approx. When I put the exhaust on the dike started to idle around 2000 give/take 50. I retarded the idle with the adjustment knob on the left side of the bike to 1300-1400 approx.
My idle now bounces from 1400 to 1300 +/- 50 when the bike is warmed up. The guy I bought the bike from (my old boss) did not do any work to or even pull the fairings off the bike and only had put 100-200 miles on the bike before I bought it. A gal had the bike as a commuter to college and had taken it to a well known motorcycle shop in Vancouver, WA and had a tune up before the bike sat in a garage for approx. a year before my boss purchased it. That is all the information I have on the bike without taking it in and having it disected.
|07-29-2014 03:23 AM|
Originally Posted by TurtleSE View Post
What they all have in common is a similar AFR curve. For all technical purposes any AFR above 14.7:1 is lean any AFR below that is rich. So when people use the terms running lean or running rich it can be misleading.
Both generation Ninjas have a point where the AFR is close to the technically lean side. It is not uncommon in the low range (2k-5k RPM) to hit the 15.0:1 mark under moderate to hard acceleration for a few brief seconds, but the engine is not in danger, providing the main jets are not too small. Because the Ninja 250 runs at high rpms, it needs to run rich in the 12.8-13.2 range. With bigger jets the AFR can get around 11.1
Here is something everyone jetting a bike should read. It's from an article on Pipe Jetting.
" Carbureted powersports vehicle manufacturers do not jet their carburetors perfectly, for two reasons. First, there are emissions considerations, mostly affecting the idle and midrange carburetor circuits. Consequently these circuits are jetted leaner than normal, and should be richened slightly for better performance. However, this rarely requires more than an adjustment to the idle mixture screw, and in some cases an adjusted slide needle height. Second, manufacturers ship their product to many different places across the globe. They purposely jet too rich on the main jet, the carburetor circuit that presents the most liability in terms of engine overheating. Therefore, all road-going powersports vehicles are jetted "fat" on the main jet. Contrary to what many people believe, but true nonetheless. Manufacturers do this because they cannot jet individually for each market, so they simply err on the rich side rather than the lean side, because the latter would present more problems. The fact is, engines are much more forgiving of a 3% rich condition than an equal lean condition, and just as importantly, few customers will notice a rich main jet, while nearly all will complain about a lean one."
The dyno jet kit #96 main jet is commonly equated to a Keihin #97.5 main jet. Stock is a Keihin # 98.
|07-29-2014 02:08 AM|
|TurtleSE||The Ninja 250, 08-12' is set up from the factory to be a bike that will pass California emissions. I don't live in California! I was having issues with my bike! I live In a city that is approximately 3500 feet above sea level. Took it in and had it re-jetted, problem solved! It was rejetted with the stage 2 dynojet kit. I have the # 96 main jets, idle was adjusted properly, carbs were balanced, Adjustable fuel needles that come in the dynojet kit are installed. I run stock exhaust and stock intake. I have very snappy throttle response and couldn't be happier. May have negatively affected my average fuel ratio slightly, but it was worth it! Take into account your regional differences and modifications then go from there. Maybe even call the dynojet tech line to see what they can specifically recommend for your set up and region? It is a little unclear in your posts, do you know if your carbs have already been jetted or not?|
|07-28-2014 11:01 AM|
Enjoy the ride and the noise.
|07-28-2014 08:19 AM|
[QUOTE=DaBlue1;51969]With the Dan Moto exhaust and a K&N air filter, you need to at the very least shim the needles. Depending on your bike, you may also need to remove the snorkel. But this may also dependent on a few other factors like altitude, temp, and humidity.
Is it better for the carbs to have a jet kit installed? That way the carbs can be synced/tuned with the engine. Will I have to adjust or have to adjust the carb after putting in the washers? Also, my bike came with the snorkel already removed. When I pulled off the stock exhaust, and was putting on the Danmoto, the pipes smelled a litte gasy like the carb may already be running rich. The carbs were re-jetted or shimmed, with the person possibly thinking the carb needed to be modded after removing the snorkel? I purchased my bike from an old boss that purchased it for someone that moved out of state and didn't pay for the bike hence why I now have purched the bike. He hadn't put more than 100 - 200 miles on the bike before I purchased so he hadn't pulled the carb out or done maintenance to it.
|07-28-2014 07:27 AM|
Your idle speed should be adjusted to 1300 +/- 50 rpms after the engine is fully warmed and the choke is off. Even though it may sound smooth at 1500 rpms, it's not necessary unless it cuts out, then you have another problem.
|07-27-2014 08:16 PM|
|TurtleSE||Not sure about the U.S. But up here when I took the 2012 in for its 1st 1000 kilometre service at the dealership the shop rate was $115/hr Canadian. So that doesn't sound too bad?|
|07-27-2014 08:00 PM|
|Clownin||Thank you, I will look in to that. Is $80 an hour a decent price for a Mech. to look at and work on my bike|
|This thread has more than 10 replies. Click here to review the whole thread.|