lost power? possible causes. looking for advice.

[walty87]

I have a 2012 ninja 250. I do have a slip on mgp growler exhaust and have shimmed with 2 washers on each needle. After doing so the bike ran great and I had zero problems.

Yesterday I took my bike to work after a week of not riding it, and I noticed if I tried to give it a lot of throttle that the engine would really rev, but it seemed like I wasn't going anywhere. Also for example I used to be able to hit 100mph in 6th at 12k or 13k rpms now im lucky to get 85 at the same rpms in 6th gear. I also noticed that if I slowly gave it throttlle it seemed to pick up speed alright, but if I just give it a lot, just the rpms drop.

anyone have any idea what's going on? Its been kind of windy, but i don't think that's the issue. Anything i should try doing to test it or anything i should check? Thanks in advance for the helps and i appreciate you reading this
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[bob706]

how's the air filter, plugs?

[DaBlue1]

An engine That won't respond when the throttle is snapped open, but it picks up speed as the throttle is closed is exhibiting a typical lean condition, however a too-large main jet can also mimic this symptom.

You shimmed, but did you remove the snorkel as well? Has the temperature changed from the time you did your mods til now. Does the engine work better when cold? Has performance fallen off as it warms up or the ambient temperature increases?

Also, if you have stock gears, it is possible you were not in 6th.
12.3k rpms in 6th= 99.8 mph
12.3k rpms in 5th= 89.1 mph

[FrugalNinja250]

Clutch is slipping. Speed and engine RPM are fixed to each other for each gear. The only way to go slower with the same RPM and gear is slipping clutch.

[jdoucet93]

+1 for the slipping clutch. There is no possible way for your rpm's to increase faster than your speed in sixth gear.
Unless you have been intentionally destroying your clutch, you need to bring your bike to a dealership and get the clutch replaced(should be covered under warrantee).

Just for future reference. I know there's a picture of a pre-gen in the back ground. But, it's the same for the 2012s.
http://dmitriy.levchenkov.com/misc/n...pm/index1.html

[Alex]

It's more likely an ignitor issue than a slipping clutch. As it fails it cause both erroneous tach readings, as well as affecting actual engine performance if it gets really bad.

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

A slipping clutch wouldn't show consistently higher tach readings for a given speed. Under load it would continue to slip more and more (very noticeably).

[walty87]

I am going to check my jet needles my next day off and make sure they're still fine. It has been a little cold lately, but I've rode it with no issues in colder conditions. Maybe I should add another washer on each side and see if that fixes the problem if it is indeed running lean?

In regards to the clutch I did notice that my couch is really tight, meaning i barley even ha e to pull in / touch my clutch lever to use it. Maybe its too tight and activating the clutch hense it reving but not going?

And is there anything i can do about the ignitor? Or test to see? Im not getting any check engine lights or anything.

Thanks guys
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[Alex]

Tell-tale symptom of the ignitor problem would be if:

- when it is cold out or when the bike first starts up, the tach reads 9000 at 70 mph
- when it is warm out or when the bike has been run for awhile, the tach now reads 10000 at 70 mph.

The actual numbers don't matter of course, the trigger is that when the ignitor gets warm, it is causing the tach to read different for the same road speed in the same gear.

[DaBlue1]

Originally Posted by Alex

...A slipping clutch wouldn't show consistently higher tach readings for a given speed. Under load it would continue to slip more and more (very noticeably).

Originally Posted by walty87

...In regards to the clutch I did notice that my couch is really tight, meaning i barley even ha e to pull in / touch my clutch lever to use it.

...is there anything i can do about the ignitor?

A bad tach could be a possibility, but unlikely by the way you describe your problem. Also a slipping clutch at high speed would likely not be fully engaged and possibly jump out of gear quick. The clutch on the Ninja does not need a lot of movement of the lever (about 3-5mm) to engage/disengage. However as a precaution you should inspect/adjust it.

[walty87]

I don't think it's just an error of wrong reading rpms. Its when I give it heavy throttle it seems like I've lost power. At first I though it was the Wind. Because I can win the engine up super loud where like I said I would be going 100mph now im stuck at 85 wot..

I need to check my needles, idk. Its just strange that it just started happening yesterday
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[Alex]

It could be a few things as listed in this thread, but some of the ignitor problems did cause what you're seeing as well. Bad fuel economy, loss of power, etc. The bad tach readings alone were more common, though.

[walty87]

so just rode it 40 miles home from work. hardly windy

this is whats happening:

I'm cruising at 70 mph at 9k rpm's in 6th geer. When I give it more throttle my rpm's will go up to 12k / 13k depending on how much throttle I give it, but the bike feels no increase... well barley any increase in power / speed. If I release the throttle, the bike kinda "catches up with itself" and barley goes faster then it was before.

Argh so annoying. I'm kinda feeling like it may be running lean and that something happened to my shim job on the carb needles. Is that possible?

[TnNinjaGirl]

Check your spark plugs and see if you are running rich/lean. That might point you in a direction.

[Alex]

Based on the last post, it does sound more like a slipping clutch. If you are giving it throttle, and you hear the engine speeding up & the tach reporting the engine going faster, yet the bike is not accelerating, then there is something wrong with the drivetrain itself (likely the clutch).

[Jinx250]

Follow the golden rule of KISS. Keep it simple S-

When you hammer the throttle and the RPMs go up but the speed does not, your clutch is slipping. BUT. That does not mena your clutch is bad. 99% of the time it's the clutch cable being in need of adjustment. Why fool around going to the dealer and swapping parts and pulling carbs when you can easily check for the most likely culprit in less than 10 minutes with zero cost? Worst case scenario, it isn't the adjustment and you move on to the next thing.

[DaBlue1]

First let's start with the basics...
With the small mods you have the bike will stop making / reach max power @ about 11k rpm. So there maybe no noticeable seat of the pants jerking power. You are close to tapped out. Also keep in mind ambient temp changes, wind and fuel blend can affect engine performance. Even though 13k rpm is the limit it is not good to ride there all the time. (not saying you do)

Riding at constant high rpms can also affect the way oil is pumped and flows. The correct oil level and a quality oil can help a lot. It is a known fact that under the right conditions, oils can shear down to a lower grade (i.e 40w becomes 30w). Is your engine unusually louder or clanky? Did it go into gear smoothly? At what rpms do you normally shift at? How does the bike perform in 5th gear? Does the same thing happen as far as high rpms and no speed?

I would take a few measures to try to reduce constant high rpm riding (just my opinion) by changing sprockets (if you have not already done so). shaving some rpms can help ensure the longevity of your engine, especially if you do a lot of hwy riding.

There has been as case where another rider's engine prematurely failed @ 6900 miles, despite better than average maintenance. (http://www.kawiforums.com/ninja-250r...n-scratch.html) All signs point to high rpms and heat.

Here are some things that others have suggested you check;
Clutch adjustment
Snorkel
Spark plugs
IC Ignitor
Tachometer (see this thread http://www.ninjette.org/forums/showp...&postcount=113)
Engine noises & oil level

Good luck

[cliff0529]

Yup, sounds like a clutch to me. Did you change your oil lately? Use a synthetic car oil maybe?

Adjust your clutch lever first, maybe it's just not adjusted right. If that doesn't address the issue, you'll need to replace the clutch pack. If it's a 2012, and you only have a few thousand miles on it take it to the dealer and get them to fix it. Unless you've been trying to stunt on the bike or doing burnouts, there's no reason you should have fried a clutch this quick.