'06 EX250 slow accel, hits a wall at 65mph

[Tessou]

Hello,

Sorry for the lack of a new member introduction. I'll get to it, promise.

I recently bought a lovely Ninjette for a low price as the owner was complaining of a lack of highway ability after owning it for three months. He thought the bike topped out at 60mph, so he was selling it to buy a 600. I noticed the same issue when I took it home. The bike accelerates really slowly. In the supposed ~7 second 0-60 timeframe, I'm fighting the bike to go over 45. I got smoked by my wife riding my other "bike", a Honda Reflex maxi scooter, from a dead stop and wailing the throttle to 11k at every shift.

Took it to my local shop, explaining that it feels like I'm getting zero throttle response past 1/2 twist. As in, if feels like the same pull at "full throttle" as I do at 1/2. Here's what they did to solve the problem.

- Unstuck cam chain tensioner.
- Replaced air filter.
- Valve job.
- Timing job.

I got a phone call yesterday morning saying that the bike runs a lot better and was good to go. The bike indeed sounded much healthier, but within a few minutes on the road I realized that all the sound in the world meant nothing since it was still accelerating slower than all of the traffic around me (they were driving leisurely while I'm pegging the tach just to keep pace). I angrily brought it right back to the shop and explained the problem that they failed to solve.

The story they're giving me is that the problem I'm describing is incredibly hard to diagnose and locate on the bike without spending a lot of money to poke around everything. My "the throttle feels half-hearted" comment seemed to mean something to them, but I haven't heard anything from them since.

I'm hoping it's something stupid like bad plugs or a battery issue, but I'm prepared for a call for a carb clean. This is my first real motorcycle since getting my endorsement, and I knew I was getting a problem child, but I'd rather not have to spend the price I paid for the bike again just to make it roadworthy.

Thoughts? Am I missing something here?

[Roark]

Is there anyone you know that can test ride it? The ninja really isn't that fast of a bike.. It's possible you're just expecting too much from it

[Ghostt]

Is it just slow? Or is it revving slowly? What's the history of the bike? Any modifications? Service history? Fresh gas? Etc...

It could be a number of things, carburetors, fuel flow issue due to faulty petcock, bad plugs, spark plug caps need to be cleaned, valve adjustment.

I'm sorry but the list isn't short.

If your in need of carburetor services PM @ducatiman. I can personally vouch for him, along with other members here and over at EX-500.com his prices are highly affordable, cheaper than most shops, and turn around time is short.

Custom Carb Service

The other items such as plugs, caps, petcock is all easley checked.

Here a write-up on the cleaning the spark plug caps, I recommend changing the plugs with NGK Iridium plugs.

Even bad plugs should do something, unless they are totally shot.

Did you renew the HT leads, and disassemble the caps?

Make sure you disassemble the caps, and clean them, and yes the caps get cruddy.

Here my write-up,

Short explanation: The inside of the hard plastic caps accumulate crud the can short out the spark. This can cause rough running or failure to start. Every time you do any work on the bike: remove them disassemble and clean them and renew the wires or at least the connections.

The long Explanation, Warning engineering information can cause Drowsiness.
The ancient cylinder design of the engine dictates that the spark emanate form the center of the combustion chamber. In order to get it there, the plugs had to be located down deep in a well between the cams. This well is a perfect place for dirt and moisture to accumulate. Then because there is no cooling water at this point the metal around the plug runs very hot. Surround this with the large amount of cool metal and you have a recipe for condensation. Now K did drill a drain hole between the fins to help (a little) but it often gets plugged up.

The moisture boils off the base of the plug and the vapor condenses on the cool plastic cap and the plug insulator. This moisture forms a easier path for the electrons to ground than jumping the gap at the plug to make a spark. Misfire.
This issue is right up there with Pilot jets as a cause of trouble.

Here's some pictures that might be helpful. I took these when I replaced the wires themselves, as it was a good time for a write-up, and the wires were OEM from 1998.

Wires are just 7mm copper core, with clear silicone jacket



















Testing the petcock, is easy, disconnect the fuel line from the carburetor, find a container, then start the bike, it should flow pretty quick, don't forget to check in both the run and RES position, then shut the bike off, no fuel should flow.

Another write-up

If your petcock is shot, save your time, and money and get a new one, the cost of rebuilding it isn't much cheaper, due to you need two separate kits, as they for some reason don't make just one.

New one cost about $65.00

http://www.partzilla.com/parts/detai...1023-1139.html

Also be sure to order the orings(92022-183 WASHER,6.2X11X1.5)and new bolts(92001-1091BOLT,6X20),trust me you'll be better off in the long run.

Rebuilding kits are about $60 total.

K&L Supply Diaphragm Only for Fuel Petcock Repair Kit 18-6638 https://www.amazon.com/dp/B0055DWO60..._s1CGub1W9N3PH

K&L Supply Fuel Petcock Repair Kit 18-2723 https://www.amazon.com/dp/B001KO2JRW..._U1CGub05DT5NT

IMHO not worth it rebuilding, also be sure to check vacuum and fuel lines for wear, holes, and cracks, if in doubt replace them. Also replace the two small O-rings on the bolts for the petcock part# 92022.

Odds are the bike was never properly serviced or taken care of, so I'd recommend a valve adjustment, you did mention the shop did a valve job, I'm assuming they did the adjustment.

Some Ninjettes live a poor and abused life, being an entry level bike.


SIDENOTE:

I did the Kawasaki ZX Ignition Coil Pack modification to eliminate the spark plug caps problem, and a stronger spark.

[ducatiman]

Tessou-

an '06 that likely sat a lot...I'll go out on a limb and suspect a fueling issue (carb internal)

I've test ridden my neighbors pregen 250 after carb work and easily reached 95 mph. Your 45 and 60 benchmarks were reached effortlessly.

Consider my carb services...https://www.ninjette.org/forums/showthread.php?t=226815

Get a price from your shop, then PM me for comparison. All you'll have to do is provide your own labor to get them off and back on again (properly)

[xXecuterXx2]

I agree with the others, 60 mph isn't were it tops out, i've hit 109 before i got scared the bike was gonna blow, and they're packed with enough acceleration to do a small wheelie in first. I would say your suffering from fuel starvation issues, or fuel delivery issues. I'll pm you with some info in a sec, just some tips that helped me sort my issues out.

[csmith12]

Air + gas + spark + compression = speed

You some some amount of all 4 already, but running out of one of them early. Check your petcock first, it's easy. I am hoping it's that simple for you.

[Tessou]

Thanks to everybody for the replies. I've been suspecting it was a fuel issue. The bike is getting 180-200 miles out of the tank before I switch to RES, so I wasn't alarmed by a loss of mileage.

Previous owner only owned the bike for three months. It had been dropped by the owner before that, resulting in two cracks in the fairing but nothing else (that he noticed, obviously). The PO simply believed that 60mph was the limit for the bike, and that the acceleration was normal. It was his first bike and he took it in for oil and filters at least once in that three months. I don't blame him for anything.

I know how quick these things should be able to go. It's not some sort of delusion where I bought an EX250 expecting ZX-6R levels of thrust. The 0-60 for the bike is stated in many places, and this bike simply doesn't hit it. I shouldn't be pegging the tach in 2nd gear to reach 40. A bike that can effortlessly zip up to 80 should not have the needle fighting to touch 60 on the speedo.

I will talk to the shop on Monday (closed Sunday) about a potential fueling issue and get back to you with their response and estimate before doing anything.

Again, thank you to everybody that chimed in.

[22R88]

Originally Posted by Tessou

Thanks to everybody for the replies. I've been suspecting it was a fuel issue. The bike is getting 180-200 miles out of the tank before I switch to RES, so I wasn't alarmed by a loss of mileage.

Previous owner only owned the bike for three months. It had been dropped by the owner before that, resulting in two cracks in the fairing but nothing else (that he noticed, obviously). The PO simply believed that 60mph was the limit for the bike, and that the acceleration was normal. It was his first bike and he took it in for oil and filters at least once in that three months. I don't blame him for anything.

I know how quick these things should be able to go. It's not some sort of delusion where I bought an EX250 expecting ZX-6R levels of thrust. The 0-60 for the bike is stated in many places, and this bike simply doesn't hit it. I shouldn't be pegging the tach in 2nd gear to reach 40. A bike that can effortlessly zip up to 80 should not have the needle fighting to touch 60 on the speedo.

I will talk to the shop on Monday (closed Sunday) about a potential fueling issue and get back to you with their response and estimate before doing anything.

Again, thank you to everybody that chimed in.

I can personally attest to Ducatiman's carb work. He refurbished my 04 250 Ninja carbs and it runs, starts and idles like a bike from the showroom. He is also quick and inexpensive and very professional to work with. Best of luck whatever you do and keep us posted.

22R88

[jkv45]

I'm thinking carb issues as well.

You will save a ton of money if you can remove the carbs yourself and send them to Ducatiman instead of having the dealer pull them and go through them.

I would say you will most likely also get a better quality job and they will be adjusted more precisely by having someone that knows Ninja carbs clean and rebuild them.

[22R88]

Originally Posted by jkv45

I'm thinking carb issues as well.

You will save a ton of money if you can remove the carbs yourself and send them to Ducatiman instead of having the dealer pull them and go through them.

I would say you will most likely also get a better quality job and they will be adjusted more precisely by having someone that knows Ninja carbs clean and rebuild them.

I concur !! If you don't think you have the ability to get carbs off maybe somebody you know can help ya as a shop is going to charge out of the wazzou to do it... it is not so hard as time consuming

22R88

[Duckfiz]

Watch this video for easy way to remove carbs then send them directly to Ducatiman.......


https://www.youtube.com/watch?v=AD5br8HCfn0

[Tessou]

Definitely taking this advice if it turns out to be the carbs. Can't get hands on the bike until tomorrow but I will update as soon as I do.

[Ghostt]

Removing them is easy, installing them is a bit harder.

[xXecuterXx2]

Originally Posted by Ghostt

Removing them is easy, installing them is a bit harder.

True dat, i've taken them out over 9 times just to get em right, still have a little bit of trouble each time i do, oh and speaking of which, some of you might remember my carb issues, i sorted them out. running like a top now

[Ghostt]

The airbox modification makes it a lot easier for sure.

http://faq.ninja250.org/wiki/Battery...r_carb_removal

[22R88]

Originally Posted by Ghostt

The airbox modification makes it a lot easier for sure.

http://faq.ninja250.org/wiki/Battery...r_carb_removal

[Tessou]

Just talked with the shop. They're going to knock out a few other maintenance items I wanted done before handing it back to me so I can pull the carbs.

[Motofool]

Originally Posted by Tessou

Just talked with the shop. They're going to knock out a few other maintenance items I wanted done before handing it back to me so I can pull the carbs.

Ask them to run a compression test and give you those numbers.

[jkv45]

Originally Posted by Tessou

Just talked with the shop. They're going to knock out a few other maintenance items I wanted done before handing it back to me so I can pull the carbs.

After this, I would invest in some tools and tackle the maintenance stuff yourself. From the sound of it, you can do it.

These bikes are pretty straight-forward to work on, and you will find that a lot of shops just bang-out the work theses days. Plenty of simple mistakes are made by "trained technicians" that shouldn't be - especially on entry level machines. You ultimately take the responsibility for any work done on your cycle, and it's usually best to learn to do it yourself so you get familiar with what to look for before a seemingly insignificant issue turns into a big problem on the road.

I'm pretty confident that a proper carb cleaning and adjustment will solve your problems - but let us know.

[Tessou]

Originally Posted by Motofool

Ask them to run a compression test and give you those numbers.

That's one of the things I asked them to do as I feared a dead cylinder at first. I'm next in line, so they're doing work on it tomorrow and Wednesday, then handing the bike to me.

As for getting tools and doing it myself: definitely. My garage is set up with space for a workshop now, so it's in the cards.

[rc racer]

When I first got my 09 ninja 250 it acted just like you describe, struggling to reach 60mph. I went through the carbs twice, replaced plugs and air filter with little to no improvement. Then I realized the battery cable where not very tight. Tightened them up with a 10mm socket (not a Phillips screwdriver) and the bike sprang to life easily pulling up to 90mph and more.

Such an easy thing to check it should have been the first thing I did not the last. Would have saved me many hours.

[Tessou]

Originally Posted by rc racer

When I first got my 09 ninja 250 it acted just like you describe, struggling to reach 60mph. I went through the carbs twice, replaced plugs and air filter with little to no improvement. Then I realized the battery cable where not very tight. Tightened them up with a 10mm socket (not a Phillips screwdriver) and the bike sprang to life easily pulling up to 90mph and more.

Such an easy thing to check it should have been the first thing I did not the last. Would have saved me many hours.

I will do this as soon as I get the bike back. I love when the problem is something so devilishly simple.

[Tessou]

Update:

Carbs have been removed and inspected. There were holes in the slide diaphragms (yes, both of them) that I could stick my finger through. Bad vacuum = power loss. Carbs otherwise in decent shape. I wish I could ask the previous previous owner what the hell they did to the bike, and also so I can punch them in the face for mistreating it like this.

Battery cables were snug. Nothing wrong there. She gets put back together for a test run in the morning. Too dang could out here to do anything right now.

[xXecuterXx2]

Stick your fingers thru?? Good Lord, think you've found your issues...

[xXecuterXx2]

also, before you splurge on new diaphragms, go give google a search on patching them, plenty of people do it.

[Tessou]

Bike is buttoned up and done. Can't test ride it as the weather is absolutely terrible since yesterday and doesn't seem to be letting up.

From everything we could test, it's running very well. I just haven't taken it out to test the speed yet.

[VaFish]

Originally Posted by Tessou

Bike is buttoned up and done. Can't test ride it as the weather is absolutely terrible since yesterday and doesn't seem to be letting up.

From everything we could test, it's running very well. I just haven't taken it out to test the speed yet.

Did you replace the diaphragms?

[xXecuterXx2]

Originally Posted by VaFish

Did you replace the diaphragms?

i sure would hope so, else he'll be going thru a loop.

[Tessou]

Originally Posted by VaFish

Did you replace the diaphragms?

Of course.

[Tessou]

She's tested and out of the shop. Runs like a champ, got her up to about 65 before I ran out of road, but there was plenty of power left at that point so I'm not worried. She's acting and accelerating just like every other EX250 I see on youtube.

We guess that at some point a PO got a cheap carb job or did it themselves poorly, and the springs punctured the diaphragms. I don't know how they could be foolish enough to pop both of them and not notice*, but they did. I could literally put my middle finger through the holes, which is fitting, as I was pissed off when I found them.

I'm also entertaining the idea that a PO botched the carb job, realized the bike was running badly, and sold it for a pittance to somebody that either didn't know better or was looking for a TLC bike. The guy I bought it from, once again, had no idea that anything was wrong with her, so I think he just got it cheap from the culprit and thought he got a good deal.

On a sour note, the first snow hits Iowa today, so as soon as I got her home, she got put on the center stand and will sleep for the winter.

[Ghostt]

This is why whenever I get a used bike I do a full teardown, and R.D.I., no surprises.

[brian12]

Mine tops out at an indicated 105 and I seriously doubt your wife could smoke me on your Honda Reflex maxi scooter.

[Tessou]

I would certainly hope not. Now that the bike is back to 100%, she gets left squarely in the dust from "go". The scooter's dead spot in the transmission between 25-40 also doesn't help her.