High Speed Miss Under Load

SmithSwede · August 30th, 2014, 02:40 PM

Any suggestions?

2012 Ninja 250 with 26,000 miles. Was running fine until problem suddenly developed.

Problem: bike starts missing and bucking under load over about 7000 rpm. This occurs if I try to go over 60 mph. Also occurs if I open throttle way open in lower gears.

Not a problem: bike starts and idles fine. Bike run fine at moderate throttle openings up to about 50 mph. In neutral (no load) bike will rev freely up to redline with no missing.

Bike is regular commuter (100 miles a day). I never leave it sit more than two weeks without doing a 100 mi commute.

What has not fixed it:

Valves adjusted to spec. Air cleaner ok. New spark plugs installed with correct gap. Bought used ECU and swapped. No change. Bought used coils--swapped and no change.

I went through and cleaned all connectors with DeoxIT. All wires and connectors appear sound. There is a good ground. Battery is one year old and fully charged.

Problem exists if bike run with gas cap open (no tank vacuum). Doesn't help if petcock set to prime. Does not help if choke applied while engine missing.

Maybe the pick up coil? (But tach works fine and it will rev to read line in neutral)

Maybe a clogged jet? (But I hate to tamper with carbs and don't see how this could occur on bike run regularly with good fuel)

Overheating a clue??? A few weeks before this missing occurred, the bike would overheat after long freeway run when I was in slow urban traffic. Problem was mud dauber nest on radiator fan preventing rotation and blowing fuse. That's fixed; does not overheat anymore. I would not think these two problems were related, but I'm suspicious because the missing started shortly after the overheat issues.

But how would they be related?

C-Bass · August 30th, 2014, 04:01 PM

Sounds like it could be possible valve trouble?

dcj13 · August 30th, 2014, 04:51 PM

Bad plug wire?

Flat cam lobe? Probably would have noticed that when checking valve clearances, though.

nbleak21 · August 31st, 2014, 07:46 AM

Have you done a compression check?

cuong-nutz · August 31st, 2014, 08:32 AM

How did you know it was overheating?

Did you notice any coolant loss?
Contaminated coolant or oil?
Compression test?
How did your spark plugs look before you replaced it? How are the new ones looking?
No dry rotted vacuum hoses?

JordanB08 · September 3rd, 2014, 07:14 AM

Im having the same issue with my 08. Is your top speed around 70?

On my bike, in 6th, I cant get it past 9K-10K. It bucks, just like your describing, on all gears except neutral. If i find anything ill be sure to past back here! This issue is killing me!!

jkv45 · September 3rd, 2014, 08:21 AM

Seems like the slides may not be lifting properly. I'd reach inside the airbox and lift/drop the slides to make sure they are moving freely. Next step may be to remove and check the diaphragms for damage.

Are both pipes the same temp?

Have you had the carbs off?

Any chance there could be significant moisture sitting in the bottom of the tank? Have you drained the floatbowls and looked at the fuel? You could dump the tank and refill with fresh gas from another location. Bad gas can give you those symptoms as well.

JordanB08 · September 3rd, 2014, 08:41 AM

Sooooo 30 mins or so after my post I checked more forums. There was a gentlemen who had kind of the same issue. He was complaining of his bike reaching 8K rpms but not being able to go further then that.

http://www.newninja.com/forums/f97/8...er-6777-6.html

TL;DR On page 6, the issue was that his girlfriend left gummy bears under the seat and it clogged up his snorkel leading to the air box. After clearing that up he found that his issue was resolved.

I was having similar issues. I went to my air box and found that the snorkel got removed from its spot and part of it pinched closed. I removed the snorkel so it has proper air for the mixture and now it pulls excellent all the way to red line. Ill be rejetting this afternoon too!!!

So, if you think its worth checking, i would check your air box and snorkel to see if its clogged, pinched, or something similar.

Cheers

http://www.kawiforums.com/ninja-250r...g-snorkel.html

SmithSwede · September 3rd, 2014, 10:18 AM

thanks for all the tips! Been too busy at work to investigate further. Will definitely do a compression check.

As to the various questions:

On my bike, it won't go past about 55 or 60 mph.

There is nothing obviously wrong on the intake side based on external observation. No missing or pinched hoses, nothing dry rotted, everything seems tight and in the right place.

Good idea about checking inside the air box for blockage, and ensuring the slides work ok.

I know it overheated because the overheat light would come on. Then I discovered a huge mud dauber nest on the radiator fan that prevented its rotation (and caused that fuse to blow). Once that was fixed, it would not overhead.

I've drained a lot of fuel--it's pretty fresh and doesn't seem to have water in it. That transferred fuel worked ok in a riding mower.

jkv45 · September 3rd, 2014, 12:11 PM

Try pulling out the snorkel...

JordanB08 · September 3rd, 2014, 03:02 PM

Quote:

Originally Posted by jkv45

Try pulling out the snorkel...

Jkv45 knows what I'm talkin bout!!

alex.s · September 3rd, 2014, 03:32 PM

i'm putting $5 on an animal in the airbox

JordanB08 · September 3rd, 2014, 04:02 PM

I got 5 on gummy bears

SmithSwede · September 13th, 2014, 02:35 PM

Thanks guys!! Turned out there was a &$:@$ mud dauber built a nest in the lower snorkel channel. Once removed, it now runs like a top.

So the bugs got me twice. They jammed my radiator fan with a nest, leading to overheating in urban traffic. Fixed that, no more overheating, ran fine at high speed.

Couple weeks later, they got my snorkel, causing the high speed miss.

JordanB08 · September 13th, 2014, 07:48 PM

Glad to hear its all worked out. I need to know though, were they any mud dabbers in the nest when you took it out?

SmithSwede · September 14th, 2014, 06:44 AM

Well, I'm afraid that some insects may have been harmed in the production of this scene from my life. I actually kept the nest--will probably frame it for my shop. But no sign of life.

I've now researched these creatures. They drink nectar from flowers and eat spiders. Indeed, their nests are filled with paralyzed spiders. Female finds spiders, stings them into paralysis but doesn't kill them, then stuffs dozens of these zombie spiders into the nest along with her eggs. Hatching larvae then eat the spiders.

Also turns out they are a well known problem for machinery. At least 3 airplane crashes have been caused by mud daubers building nest in pitot tubes, which then interferes with accuracy of air speed gauges.

August 30th, 2014, 02:40 PM	#1
SmithSwede ninjette.org member Name: Prescott Location: Terrell, Texas Join Date: Nov 2011 Motorcycle(s): 2007 BMW F800S; 2012 Ninja 250; 2013 Moto Guzzi V7 Stone, 2016 Triumph Street Triple Rx; 1996 Ducati 900 SS CR Posts: 77	High Speed Miss Under Load Any suggestions? 2012 Ninja 250 with 26,000 miles. Was running fine until problem suddenly developed. Problem: bike starts missing and bucking under load over about 7000 rpm. This occurs if I try to go over 60 mph. Also occurs if I open throttle way open in lower gears. Not a problem: bike starts and idles fine. Bike run fine at moderate throttle openings up to about 50 mph. In neutral (no load) bike will rev freely up to redline with no missing. Bike is regular commuter (100 miles a day). I never leave it sit more than two weeks without doing a 100 mi commute. What has not fixed it: Valves adjusted to spec. Air cleaner ok. New spark plugs installed with correct gap. Bought used ECU and swapped. No change. Bought used coils--swapped and no change. I went through and cleaned all connectors with DeoxIT. All wires and connectors appear sound. There is a good ground. Battery is one year old and fully charged. Problem exists if bike run with gas cap open (no tank vacuum). Doesn't help if petcock set to prime. Does not help if choke applied while engine missing. Maybe the pick up coil? (But tach works fine and it will rev to read line in neutral) Maybe a clogged jet? (But I hate to tamper with carbs and don't see how this could occur on bike run regularly with good fuel) Overheating a clue??? A few weeks before this missing occurred, the bike would overheat after long freeway run when I was in slow urban traffic. Problem was mud dauber nest on radiator fan preventing rotation and blowing fuse. That's fixed; does not overheat anymore. I would not think these two problems were related, but I'm suspicious because the missing started shortly after the overheat issues. But how would they be related?

August 31st, 2014, 08:32 AM	#5
cuong-nutz RIP Alex Name: Cuong Location: Houston, TX Join Date: Apr 2011 Motorcycle(s): '10 250r, '09 265r Posts: A lot. Blog Entries: 2	How did you know it was overheating? Did you notice any coolant loss? Contaminated coolant or oil? Compression test? How did your spark plugs look before you replaced it? How are the new ones looking? No dry rotted vacuum hoses? __________________________________________________ HalfFast Racing Team Serving Greater Houston Area Riders:WFO Riders MotoHouston HPC CMRA Ride Smart Fastline Lone Star Track Days

September 3rd, 2014, 03:32 PM	#12
alex.s wat Name: wat Location: tustin/long beach Join Date: Sep 2009 Motorcycle(s): wat Posts: Too much. Blog Entries: 5 MOTM - Oct '12, Feb '14	i'm putting $5 on an animal in the airbox __________________________________________________

September 13th, 2014, 02:35 PM	#14
SmithSwede ninjette.org member Name: Prescott Location: Terrell, Texas Join Date: Nov 2011 Motorcycle(s): 2007 BMW F800S; 2012 Ninja 250; 2013 Moto Guzzi V7 Stone, 2016 Triumph Street Triple Rx; 1996 Ducati 900 SS CR Posts: 77	Thanks guys!! Turned out there was a &$:@$ mud dauber built a nest in the lower snorkel channel. Once removed, it now runs like a top. So the bugs got me twice. They jammed my radiator fan with a nest, leading to overheating in urban traffic. Fixed that, no more overheating, ran fine at high speed. Couple weeks later, they got my snorkel, causing the high speed miss.
	1 out of 1 members found this post helpful.

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August 30th, 2014, 04:01 PM	#2
C-Bass ninjette.org member Name: C-Bass Location: Alberta Join Date: Mar 2014 Motorcycle(s): Currently own: 98 Honda VTR1000, 02 Suzuki's DR200 & DR650, 04 & 08 BUSA's, 05 Ducati SS1000, 12 Ninja 250R SE Posts: 59	Sounds like it could be possible valve trouble?

August 30th, 2014, 04:51 PM	#3
dcj13 Participant Name: Dave Location: South of Seattle Join Date: Oct 2012 Motorcycle(s): '94 K75 std Posts: Too much. MOTM - Aug '15	Bad plug wire? Flat cam lobe? Probably would have noticed that when checking valve clearances, though.

August 31st, 2014, 07:46 AM	#4
nbleak21 ninjette.org member Name: Nick Location: TN Join Date: Aug 2014 Motorcycle(s): '09 Ninja 250r Posts: 43	Have you done a compression check?

September 3rd, 2014, 07:14 AM	#6
JordanB08 ninjette.org member Name: Jordan Location: Viera, FL Join Date: Jul 2014 Motorcycle(s): 08 Ninja 250 Posts: 15	Im having the same issue with my 08. Is your top speed around 70? On my bike, in 6th, I cant get it past 9K-10K. It bucks, just like your describing, on all gears except neutral. If i find anything ill be sure to past back here! This issue is killing me!!

September 3rd, 2014, 08:21 AM	#7
jkv45 Rev Limiter Name: Jay Location: WI Join Date: Jul 2013 Motorcycle(s): '06 SV650n, '00 Derbi GPR, '64 CA77 Dream 305, '70 CL450 Scrambler, numerous dirt bikes Posts: A lot. MOTM - Jun '18, Oct '16	Seems like the slides may not be lifting properly. I'd reach inside the airbox and lift/drop the slides to make sure they are moving freely. Next step may be to remove and check the diaphragms for damage. Are both pipes the same temp? Have you had the carbs off? Any chance there could be significant moisture sitting in the bottom of the tank? Have you drained the floatbowls and looked at the fuel? You could dump the tank and refill with fresh gas from another location. Bad gas can give you those symptoms as well.

September 3rd, 2014, 08:41 AM	#8
JordanB08 ninjette.org member Name: Jordan Location: Viera, FL Join Date: Jul 2014 Motorcycle(s): 08 Ninja 250 Posts: 15	Sooooo 30 mins or so after my post I checked more forums. There was a gentlemen who had kind of the same issue. He was complaining of his bike reaching 8K rpms but not being able to go further then that. http://www.newninja.com/forums/f97/8...er-6777-6.html TL;DR On page 6, the issue was that his girlfriend left gummy bears under the seat and it clogged up his snorkel leading to the air box. After clearing that up he found that his issue was resolved. I was having similar issues. I went to my air box and found that the snorkel got removed from its spot and part of it pinched closed. I removed the snorkel so it has proper air for the mixture and now it pulls excellent all the way to red line. Ill be rejetting this afternoon too!!! So, if you think its worth checking, i would check your air box and snorkel to see if its clogged, pinched, or something similar. Cheers http://www.kawiforums.com/ninja-250r...g-snorkel.html

September 3rd, 2014, 10:18 AM	#9
SmithSwede ninjette.org member Name: Prescott Location: Terrell, Texas Join Date: Nov 2011 Motorcycle(s): 2007 BMW F800S; 2012 Ninja 250; 2013 Moto Guzzi V7 Stone, 2016 Triumph Street Triple Rx; 1996 Ducati 900 SS CR Posts: 77	thanks for all the tips! Been too busy at work to investigate further. Will definitely do a compression check. As to the various questions: On my bike, it won't go past about 55 or 60 mph. There is nothing obviously wrong on the intake side based on external observation. No missing or pinched hoses, nothing dry rotted, everything seems tight and in the right place. Good idea about checking inside the air box for blockage, and ensuring the slides work ok. I know it overheated because the overheat light would come on. Then I discovered a huge mud dauber nest on the radiator fan that prevented its rotation (and caused that fuse to blow). Once that was fixed, it would not overhead. I've drained a lot of fuel--it's pretty fresh and doesn't seem to have water in it. That transferred fuel worked ok in a riding mower.

September 3rd, 2014, 12:11 PM	#10
jkv45 Rev Limiter Name: Jay Location: WI Join Date: Jul 2013 Motorcycle(s): '06 SV650n, '00 Derbi GPR, '64 CA77 Dream 305, '70 CL450 Scrambler, numerous dirt bikes Posts: A lot. MOTM - Jun '18, Oct '16	Try pulling out the snorkel...

September 3rd, 2014, 04:02 PM	#13
JordanB08 ninjette.org member Name: Jordan Location: Viera, FL Join Date: Jul 2014 Motorcycle(s): 08 Ninja 250 Posts: 15	I got 5 on gummy bears

September 13th, 2014, 07:48 PM	#15
JordanB08 ninjette.org member Name: Jordan Location: Viera, FL Join Date: Jul 2014 Motorcycle(s): 08 Ninja 250 Posts: 15	Glad to hear its all worked out. I need to know though, were they any mud dabbers in the nest when you took it out?

September 14th, 2014, 06:44 AM	#16
SmithSwede ninjette.org member Name: Prescott Location: Terrell, Texas Join Date: Nov 2011 Motorcycle(s): 2007 BMW F800S; 2012 Ninja 250; 2013 Moto Guzzi V7 Stone, 2016 Triumph Street Triple Rx; 1996 Ducati 900 SS CR Posts: 77	Well, I'm afraid that some insects may have been harmed in the production of this scene from my life. I actually kept the nest--will probably frame it for my shop. But no sign of life. I've now researched these creatures. They drink nectar from flowers and eat spiders. Indeed, their nests are filled with paralyzed spiders. Female finds spiders, stings them into paralysis but doesn't kill them, then stuffs dozens of these zombie spiders into the nest along with her eggs. Hatching larvae then eat the spiders. Also turns out they are a well known problem for machinery. At least 3 airplane crashes have been caused by mud daubers building nest in pitot tubes, which then interferes with accuracy of air speed gauges.