Loss of power after 11000rpm?

Robbo81 · January 29th, 2010, 02:30 AM

Has anybody else noticed a loss in power after 11000rpm? It doesn't bog down or anything like that, it just feels like its not making any more power after 11000rpm. Is this normal?

Since I'ved shimmed the carb needles my bike goes way better than before throughout the rev range but I can't really remember how it performed up that high in the revs as I didn't have the bike for long before carrying out this mod. I've noticed alot of people talked about getting aftermarket exhaust systems to over come this issue but I thought I better ask on the forum just incase. Maybe I need to remove or install another shim? I currently have 2 shims under each needle with the snorkal removed, apart from that my bike is completely stock. I'm just a bit worried cause I don't want to burn anything out.

The reason I ask is because I just took my mates zzr250 for a run (that is completely stock) and it keeps pulling right through the rev range and I've heard that both these bikes are very similar mechanically so why would mine be any differant? Could it be cause the zzr's have duel exhausts from factory meaning less restrictions on a standard exhaust system? Or maybe the run richer than our bikes?

Alex · January 31st, 2010, 12:46 AM

The pre-gen motors do seem less restricted as the revs get up there, but even so a new-gen motor shouldn't feel like it's making no more power over 11K. Hard to say if everything is running as it should without figuring out how it ran before changing the shims, but odds are 2 washers aren't going to change a heck of alot at full throttle at high revs anyway.

kkim · January 31st, 2010, 12:58 AM

try dropping the main jets one step and see if the power builds thru to redline. it sounds like it may be a tad rich at full throttle.

is your air cleaner element clean? how do your plugs look?

250Rocket · January 31st, 2010, 01:28 AM

Normal to a certain degree. The peak hits between 9.5k to 11.5k RPM. SO you will feel a loss, i know i do, but it's not night and day, just slightly noticeable.

Robbo81 · January 31st, 2010, 01:37 AM

Hmmm. I was thinking the same thing guys. Was kind of hoping you would all come back and say, hey they all do that and don't worry about it..... Doh!! My bike always runs on 98 octane fuel here in aus if that has anything to do with it. Might have to do as you said. Time to strip it down and remove a washer. It doesn't stall, hold back or anything, and it still revs fine. Just once I hit 11000rpm, It doesn't pull the way it does at 9000rpm. I haven't checked my plugs yet, but I know my filter is clean. Maybe she is running a bit rich because ever since the carb shimming my mpg isn't as good as before.

Thanx heaps guy's. Might try to strip it down through the week and test it out next weekend. I think I'll replace those JIS screws with something easier to access, in hex maybe. I'll let you know. And please let me know if you guys think of something else.

Robbo81 · January 31st, 2010, 01:42 AM

Sorry Rob I just saw your post. As you said its not a huge drop, but enough to notice.

Might do what KKim said first and check my plugs. Its white for lean, black for rich and gold for just right isn't it?

kkim · January 31st, 2010, 01:42 AM

http://faq.ninja250.org/wiki/How_to_...e_your_jetting

kkim · January 31st, 2010, 01:46 AM

Quote:

Originally Posted by Robbo81

Its white for lean, black for rich and gold for just right isn't it?

http://www.usaimports.co.uk/Mopar_Te...ug_Reading.htm

Robbo81 · January 31st, 2010, 01:57 AM

Thanks KKim, Legend

bdavison · January 31st, 2010, 07:14 AM

At 11g you are reaching the upper limits of the powerband. The powerband is between 8-11g...with the peak right around 10g.

250Rocket · January 31st, 2010, 01:05 PM

http://www.mcnews.com/mcn/features/200806ninja.pdf

Last page, has all the stock stats from a reliable source.

Look at the graphs and you'll see why.

Cedilla · January 31st, 2010, 02:08 PM

Mine feels the same way, I think thats how its supposed to be.

Angel-be-Good · January 31st, 2010, 10:01 PM

Here's a dyno (blue is stock).

After 11k, power starts to trail off, to about 15-20% less than peak power by redline.

Robbo81 · February 1st, 2010, 12:55 AM

Hmmmm, Maybe there is nothing wrong with it then. Looks like I'll have to either con the mrs into letting me get a full exhaust or I'll have to just start shifting earlier

almost40 · February 3rd, 2010, 11:57 AM

Dynojet ket with a 100 main jet and full exhaust and youll bounce the bike off the rev limiter while still pulling hard. No more flat spot after 11k.

January 29th, 2010, 02:30 AM	#1
Robbo81 ninjette.org member Name: Robert Location: sydney Join Date: Sep 2009 Motorcycle(s): 250r Posts: 35	Loss of power after 11000rpm? Has anybody else noticed a loss in power after 11000rpm? It doesn't bog down or anything like that, it just feels like its not making any more power after 11000rpm. Is this normal? Since I'ved shimmed the carb needles my bike goes way better than before throughout the rev range but I can't really remember how it performed up that high in the revs as I didn't have the bike for long before carrying out this mod. I've noticed alot of people talked about getting aftermarket exhaust systems to over come this issue but I thought I better ask on the forum just incase. Maybe I need to remove or install another shim? I currently have 2 shims under each needle with the snorkal removed, apart from that my bike is completely stock. I'm just a bit worried cause I don't want to burn anything out. The reason I ask is because I just took my mates zzr250 for a run (that is completely stock) and it keeps pulling right through the rev range and I've heard that both these bikes are very similar mechanically so why would mine be any differant? Could it be cause the zzr's have duel exhausts from factory meaning less restrictions on a standard exhaust system? Or maybe the run richer than our bikes? Last futzed with by Robbo81; January 30th, 2010 at 06:29 PM.

January 31st, 2010, 12:46 AM	#2
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	The pre-gen motors do seem less restricted as the revs get up there, but even so a new-gen motor shouldn't feel like it's making no more power over 11K. Hard to say if everything is running as it should without figuring out how it ran before changing the shims, but odds are 2 washers aren't going to change a heck of alot at full throttle at high revs anyway. __________________________________________________ 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)

January 31st, 2010, 01:28 AM	#4
250Rocket ninjette.org member Name: Rob Location: Montreal, Canada Join Date: Apr 2009 Motorcycle(s): '09 Ninja 250R Posts: 171	Normal to a certain degree. The peak hits between 9.5k to 11.5k RPM. SO you will feel a loss, i know i do, but it's not night and day, just slightly noticeable. __________________________________________________ Back on the road again Season 2010 Dam it feels good!

January 31st, 2010, 01:05 PM	#11
250Rocket ninjette.org member Name: Rob Location: Montreal, Canada Join Date: Apr 2009 Motorcycle(s): '09 Ninja 250R Posts: 171	http://www.mcnews.com/mcn/features/200806ninja.pdf Last page, has all the stock stats from a reliable source. Look at the graphs and you'll see why. __________________________________________________ Back on the road again Season 2010 Dam it feels good!

January 31st, 2010, 02:08 PM	#12
Cedilla ninjette.org sage Name: Chris Location: Huntsville, AL Join Date: May 2009 Motorcycle(s): 2009 Ninja 250 (sold) Posts: 755	Mine feels the same way, I think thats how its supposed to be. __________________________________________________ The Ninjette is not a disposable bike. You are not ever supposed to get rid of it. It is like a [friendly] herpes virus.... once you got it, you get keep it forever. Originally posted by-Headshrink

January 31st, 2010, 12:58 AM	#3
kkim Join Date: Nov 2008 Posts: Too much.	try dropping the main jets one step and see if the power builds thru to redline. it sounds like it may be a tad rich at full throttle. is your air cleaner element clean? how do your plugs look?

January 31st, 2010, 01:37 AM	#5
Robbo81 ninjette.org member Name: Robert Location: sydney Join Date: Sep 2009 Motorcycle(s): 250r Posts: 35	Hmmm. I was thinking the same thing guys. Was kind of hoping you would all come back and say, hey they all do that and don't worry about it..... Doh!! My bike always runs on 98 octane fuel here in aus if that has anything to do with it. Might have to do as you said. Time to strip it down and remove a washer. It doesn't stall, hold back or anything, and it still revs fine. Just once I hit 11000rpm, It doesn't pull the way it does at 9000rpm. I haven't checked my plugs yet, but I know my filter is clean. Maybe she is running a bit rich because ever since the carb shimming my mpg isn't as good as before. Thanx heaps guy's. Might try to strip it down through the week and test it out next weekend. I think I'll replace those JIS screws with something easier to access, in hex maybe. I'll let you know. And please let me know if you guys think of something else.

January 31st, 2010, 01:42 AM	#6
Robbo81 ninjette.org member Name: Robert Location: sydney Join Date: Sep 2009 Motorcycle(s): 250r Posts: 35	Sorry Rob I just saw your post. As you said its not a huge drop, but enough to notice. Might do what KKim said first and check my plugs. Its white for lean, black for rich and gold for just right isn't it?

January 31st, 2010, 01:57 AM	#9
Robbo81 ninjette.org member Name: Robert Location: sydney Join Date: Sep 2009 Motorcycle(s): 250r Posts: 35	Thanks KKim, Legend

January 31st, 2010, 07:14 AM	#10
bdavison Wartown, USA Name: Bryan Location: Warner Robins, GA Join Date: Nov 2009 Motorcycle(s): 2009 Ninja 250R SE, 2007 Ninja 650R, and assorted other bikes Posts: A lot.	At 11g you are reaching the upper limits of the powerband. The powerband is between 8-11g...with the peak right around 10g.

January 31st, 2010, 10:01 PM	#13
Angel-be-Good ninjette.org guru Name: Ryan Location: San Francisco Join Date: Dec 2008 Motorcycle(s): '08 Ninja 250, '11 Street Triple R Posts: 337	Here's a dyno (blue is stock). After 11k, power starts to trail off, to about 15-20% less than peak power by redline. __________________________________________________ The Sunday Best \| Current mileage: 50,000

February 1st, 2010, 12:55 AM	#14
Robbo81 ninjette.org member Name: Robert Location: sydney Join Date: Sep 2009 Motorcycle(s): 250r Posts: 35	Hmmmm, Maybe there is nothing wrong with it then. Looks like I'll have to either con the mrs into letting me get a full exhaust or I'll have to just start shifting earlier

February 3rd, 2010, 11:57 AM	#15
almost40 ninjette.org Monkey Spank Name: Kevin Location: Illinois Join Date: Apr 2009 Motorcycle(s): 2008 250R Track-Bike Woodcraft clip-ons and rearsets FZ-6 track bike Posts: A lot.	Dynojet ket with a 100 main jet and full exhaust and youll bounce the bike off the rev limiter while still pulling hard. No more flat spot after 11k. __________________________________________________ Black 250R Full Area P QC Dyno Jet Kit 100 main 41T Rear Sprocket

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
loss of power	reignman	1986 - 2007 Ninja 250R Tech Talk	7	June 1st, 2013 04:04 AM
Loss of power, but I think I know why...	rmorse	2008 - 2012 Ninja 250R Tech Talk	1	August 13th, 2012 08:16 AM
Loss of power?	oblivion007	2008 - 2012 Ninja 250R Tech Talk	2	June 4th, 2011 08:07 PM
Loss of power on highway (all the power)	aldenso	2008 - 2012 Ninja 250R Tech Talk	10	May 7th, 2011 10:27 PM
Loss of power?	sudapuff	1986 - 2007 Ninja 250R Tech Talk	1	October 19th, 2010 10:48 AM