Erratic idle, wont start cold, etc.

d16soda · August 11th, 2011, 09:33 AM

So, I have a 2005 Ninja 250 - really great condition mechanically. It only has 2,000 miles and has been maintained it's whole life. Recently went to jail, and didnt run the gas out of the carbs before i went. I know, bonehead move. Rebuilt and cleaned the carbs, synchronized the throttle, and put it all back together. Here is my issue:

Wont start cold. Choke seems to make no difference. I have to use ether/carb cleaner to get it started initially.
When it runs, the idle is crazy and wont seem to stay still. I am constantly adjusting it to make it rideable.
While riding, seems to surge a tiny bit, not too much though.
Cant run it anywhere near stable until it is completely warmed up.

What are my options? Ideas? The carb is correctly connected to the airbox with no air leak as far as i am concerned and the two intake hoses to the block are snug and fitted correctly.

Edit: recleaned and resynced carbs, and put it back on the bike. Idles fine, jumps up a little like there is a vacuum leak. About to go on my break at work (work in a mechanics shop so i have access to tools, lifts, etc. on my break) and I am going to fire up my bike and let it warm up to see if problems persist.

Yesterday, although idling fine, I put it in gear, and when i released the clutch the tach and lights would die and the engine would slowly fall like the fuel was being cut. If i pulled the clutch the gauge cluster would come back to life and the engine would continue idling. Now, I dont remember having the kickstand down but I did read that there was a kickstand switch that would prevent it from moving in gear. Also, my battery was very dead (left the key on during work up until lunch). Battery is charged reading 13v, installed, and i will make sure i have the kickstand up this time. Any ideas though why the clutch engaging would kill the enging?

Felipe the Ant · August 11th, 2011, 09:58 AM

The kickstand switch would have killed the engine as soon as you left neutral so I doubt that has much to do with it. How high were you revving it when you were releasing the clutch? If the battery is dead perhaps the bike was just getting barely enough power to run from the alternator? Try charging/swapping the battery first and see where that gets you

Alex · August 11th, 2011, 10:01 AM

I think you're on the right track. Key suspects are either clogged pilot jets (even after the cleaning), or a vacuum leak on reassembly.

d16soda · August 11th, 2011, 10:26 AM

Well, just took it for a quick 15 minute ride. It was idling fine warm but when I clutch in at a stop sign, it seems to hang longer than it needs to. Im not sure where this vacuum leak is :/

d16soda · August 17th, 2011, 09:26 AM

so guys, still having the same problem. Took the carbs off AGAIN, reseated the boots, new clamps, cleaned, resynchronized the throttle plates, and make sure things were in order.

Now, when i spray throttle body cleaner (Carb/choke cleaner) on the little throttle bracket where the wires hook in, the idle shoots up. I dont understand how the throttle bracket could be leaking air. Anything like this ever happened to anyone? Is there a common error here? What exactly over the throttle bracket could even leak into the engine? I am at a loss.

GeorgeRYoung · August 17th, 2011, 10:28 AM

I've never taken the butterflies apart on the EX250 carbs, but I have on another bike (XZ550).

There's supposed to be a seal on the shaft where it passes thru the carb body to keep air from leaking in.

Sounds like your carb is leaking past that seal.

If that is the problem, you might be able to replace them with little O-rings.

d16soda · August 18th, 2011, 09:31 AM

Quote:

Originally Posted by GeorgeRYoung

I've never taken the butterflies apart on the EX250 carbs, but I have on another bike (XZ550).

There's supposed to be a seal on the shaft where it passes thru the carb body to keep air from leaking in.

Sounds like your carb is leaking past that seal.

If that is the problem, you might be able to replace them with little O-rings.

Okay, thanks for the reply. I am trying to match up the seal with what i have in stock in my shop so i can avoid going to a parts store. I have aluminium and copper O-rings of various sizes. Does anyone know ahead of time if these should suffice given I have a size that fits?

d16soda · August 24th, 2011, 09:21 AM

Bump.
Going to try to do this today and was hoping for some isight on the o-rings.

d16soda · August 24th, 2011, 01:52 PM

No one? I cant necessarily figure out to get to the bushing/o-ring behind the throttle. Do i remove the 4 screws on the two throttle plaes inside the carb and it just slides out?

choneofakind · August 24th, 2011, 02:12 PM

I'm sorry. I've never taken apart that portion of the carbs

August 11th, 2011, 09:33 AM	#1
d16soda ninjette.org member Name: pj Location: Atlanta Join Date: Jun 2011 Motorcycle(s): 2005 Ninja 250 Posts: 37	Erratic idle, wont start cold, etc. So, I have a 2005 Ninja 250 - really great condition mechanically. It only has 2,000 miles and has been maintained it's whole life. Recently went to jail, and didnt run the gas out of the carbs before i went. I know, bonehead move. Rebuilt and cleaned the carbs, synchronized the throttle, and put it all back together. Here is my issue: Wont start cold. Choke seems to make no difference. I have to use ether/carb cleaner to get it started initially. When it runs, the idle is crazy and wont seem to stay still. I am constantly adjusting it to make it rideable. While riding, seems to surge a tiny bit, not too much though. Cant run it anywhere near stable until it is completely warmed up. What are my options? Ideas? The carb is correctly connected to the airbox with no air leak as far as i am concerned and the two intake hoses to the block are snug and fitted correctly. Edit: recleaned and resynced carbs, and put it back on the bike. Idles fine, jumps up a little like there is a vacuum leak. About to go on my break at work (work in a mechanics shop so i have access to tools, lifts, etc. on my break) and I am going to fire up my bike and let it warm up to see if problems persist. Yesterday, although idling fine, I put it in gear, and when i released the clutch the tach and lights would die and the engine would slowly fall like the fuel was being cut. If i pulled the clutch the gauge cluster would come back to life and the engine would continue idling. Now, I dont remember having the kickstand down but I did read that there was a kickstand switch that would prevent it from moving in gear. Also, my battery was very dead (left the key on during work up until lunch). Battery is charged reading 13v, installed, and i will make sure i have the kickstand up this time. Any ideas though why the clutch engaging would kill the enging?

August 11th, 2011, 10:01 AM	#3
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	I think you're on the right track. Key suspects are either clogged pilot jets (even after the cleaning), or a vacuum leak on reassembly. __________________________________________________ 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)

August 17th, 2011, 10:28 AM	#6
GeorgeRYoung ninjette.org member Name: George Location: Ottawa, Canada Join Date: Jun 2011 Motorcycle(s): EX250, C10 Concours Posts: 109	Butterfly shaft seals I've never taken the butterflies apart on the EX250 carbs, but I have on another bike (XZ550). There's supposed to be a seal on the shaft where it passes thru the carb body to keep air from leaking in. Sounds like your carb is leaking past that seal. If that is the problem, you might be able to replace them with little O-rings.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Gas smell and erratic idle	Noobman	2008 - 2012 Ninja 250R Tech Talk	5	May 25th, 2014 10:57 PM
Erratic idle	Jefft	2008 - 2012 Ninja 250R Tech Talk	4	November 4th, 2013 12:38 PM
Sluggish rev, erratic idle, dies with throttle	Fappy	2008 - 2012 Ninja 250R Tech Talk	12	October 8th, 2012 06:20 AM
Idle jumps to 9000 rpm on choke then wont stay idle after off	Shawn250	2008 - 2012 Ninja 250R Tech Talk	1	June 19th, 2012 06:45 AM
bike wont idle	james250ninja	1986 - 2007 Ninja 250R Tech Talk	7	April 1st, 2010 12:05 PM

August 11th, 2011, 09:58 AM	#2
Felipe the Ant ninjette.org sage Name: . Location: . Join Date: May 2011 Motorcycle(s): 2011 Ninja 250R SE GREEN! Posts: 562	The kickstand switch would have killed the engine as soon as you left neutral so I doubt that has much to do with it. How high were you revving it when you were releasing the clutch? If the battery is dead perhaps the bike was just getting barely enough power to run from the alternator? Try charging/swapping the battery first and see where that gets you

August 11th, 2011, 10:26 AM	#4
d16soda ninjette.org member Name: pj Location: Atlanta Join Date: Jun 2011 Motorcycle(s): 2005 Ninja 250 Posts: 37	Well, just took it for a quick 15 minute ride. It was idling fine warm but when I clutch in at a stop sign, it seems to hang longer than it needs to. Im not sure where this vacuum leak is :/

August 17th, 2011, 09:26 AM	#5
d16soda ninjette.org member Name: pj Location: Atlanta Join Date: Jun 2011 Motorcycle(s): 2005 Ninja 250 Posts: 37	so guys, still having the same problem. Took the carbs off AGAIN, reseated the boots, new clamps, cleaned, resynchronized the throttle plates, and make sure things were in order. Now, when i spray throttle body cleaner (Carb/choke cleaner) on the little throttle bracket where the wires hook in, the idle shoots up. I dont understand how the throttle bracket could be leaking air. Anything like this ever happened to anyone? Is there a common error here? What exactly over the throttle bracket could even leak into the engine? I am at a loss.

August 24th, 2011, 09:21 AM	#8
d16soda ninjette.org member Name: pj Location: Atlanta Join Date: Jun 2011 Motorcycle(s): 2005 Ninja 250 Posts: 37	Bump. Going to try to do this today and was hoping for some isight on the o-rings.

August 24th, 2011, 01:52 PM	#9
d16soda ninjette.org member Name: pj Location: Atlanta Join Date: Jun 2011 Motorcycle(s): 2005 Ninja 250 Posts: 37	No one? I cant necessarily figure out to get to the bushing/o-ring behind the throttle. Do i remove the 4 screws on the two throttle plaes inside the carb and it just slides out?

August 24th, 2011, 02:12 PM	#10
choneofakind ninjette.org certified postwhore Name: . Location: . Join Date: Feb 2011 Motorcycle(s): . Posts: Too much. MOTM - Feb '13, Feb '14	I'm sorry. I've never taken apart that portion of the carbs