Dying at idle with choke off

jonnybravo9 · September 29th, 2014, 09:09 PM

I'm about ready to chew nails on this one, could really use some advice.

My friends 2009 ninja 250, stock as far as I know, sat for over a year, she says it ran fine when she parked it. Would start but difficult to keep alive when we pulled it out of storage.

Pulled the carbs and went through them completely (tons of varnish and gunk throughout), cleaned everything thoroughly, double-checked the jets to make sure they are clear, drained the gas tank and put in fresh gas. Re-installed everything.

Fired it up. it would start, but ran pretty rough. Took out out for a test spin, it took some coaxing to get the RPMs up, and then had absolutely abysmal power, died at idle, even with the choke on. Tried adjusting the pilot screws out from 2 1/2 turns, could not get any better results.

Tore down the carbs again just to be sure there was no blockage (didn't find anything), followed a breakdown diagram when rebuilding, I'm 99% sure they are back together correctly. This time around, I adjusted the idle up to above 3K RPMs to make it die less. I think I also managed to do something different when I put it back together, because it seems to run better.

It now has good throttle response and power at > 3K RPMs as long as the choke is on, although it "seeks" a little while idling, but does not die. However, as soon as I touch the choke, even halfway, the RPMs start to drop down to a chug, then it dies within 3-5 seconds of touching the choke.

I also checked the left side spark plug, it looked fine (no black or white buildup) so I didn't bother pulling the right.

It must be running lean right? Or possibly a vacuum leak as well? I'm going to replace all the hoses tomorrow, and remove the California emissions garbage (plugging and re-routing per a guide I found on this forum).

I haven't messed with the pilot screws much yet because it's nearly impossible for me to get my hands in there and adjust them, I just left them at about 2 3/4 turns. Does anyone have reccomendations for how to adjust those damn things more easily?

If anyone can give me some suggestions for possible fixes to try, I would greatly appreciate it.

csmith12 · September 29th, 2014, 09:14 PM

Welcome John!

Don't just throw parts at it. To check for a vac leak, spritz some carb cleaner around things and listen for idle changes. But first... I assume you checked the air box right? And... it seems as of late, bugs have been infesting bike's snorkle tubes. So don't forget to check that too.

jonnybravo9 · September 29th, 2014, 09:32 PM

Thanks Chris!

I'm not sure what you mean by "checked the air box"? As in for wasp nests and crap? I did open up the side, filter looks clean, I didn't notice anything unusual. Where all should I check elsewise? Did a quick bit of googling but cannot find the snorkel tube location? Although the bugs out here in SoCal are generally not too bad.

Edit: Will do the carb cleaner check, you're supposed to hit all the connection points for the vacuum fittings and intake connections, right?

csmith12 · September 29th, 2014, 09:53 PM

Quote:

Originally Posted by jonnybravo9

I'm not sure what you mean by "checked the air box"? As in for wasp nests and crap? I did open up the side, filter looks clean, I didn't notice anything unusual.

Yep exactly! And look all up inside there too, a light goes a long way.

Quote:

Originally Posted by jonnybravo9

Did a quick bit of googling but cannot find the snorkel tube location? Although the bugs out here in SoCal are generally not too bad.

Edit: Will do the carb cleaner check, you're supposed to hit all the connection points for the vacuum fittings and intake connections, right?

This pic should help and again, a little light goes a long way. And yep, just a little spritz of carb cleaner around those areas is enough to change how the bike runs if it's vac leaking.

jonnybravo9 · September 29th, 2014, 10:00 PM

Got it!

Will do tomorrow and post a follow up

choneofakind · September 30th, 2014, 02:03 AM

It has sat for a year. Pour the correct amount of carb cleaner in with the gas and ride that thing for an hour hard. It will help.

jonnybravo9 · October 2nd, 2014, 09:17 PM

Hey, so I finally had time to mess with it today (crazy week at work). Airbox and snorkel tubes are clean.

I discovered that my boots between the airbox and carbs, and also between the carbs and engine block were not seated right. Got everything seated and fired it up, still running as I described, but seemed a bit better.

After spraying bursts of carb cleaner around, I narrowed it down to the spot shown in the picture below (sorry for quality). Spritzing a burst at site 1 seems to produce the largest rev. Sites 2 and 3 produce medium ish revs. All other locations get nothing.

I'm guessing it's the boot between the carb and engine that isn't sealed properly. I don't know what else it would be.... I tightened the clamps as much as possible on the boot and that didn't make a difference. I don't see how I could have managed it, but maybe I screwed up the boot when installing it and damaged it somehow.

Any ideas before I order a new one and slap it on there?

carb.png

September 29th, 2014, 09:09 PM	#1
jonnybravo9 ninjette.org newbie Name: John Location: Los Angeles Join Date: Sep 2014 Motorcycle(s): 2009 Ninja 250, 2001 Honda CBR F4i Posts: 4	Dying at idle with choke off I'm about ready to chew nails on this one, could really use some advice. My friends 2009 ninja 250, stock as far as I know, sat for over a year, she says it ran fine when she parked it. Would start but difficult to keep alive when we pulled it out of storage. Pulled the carbs and went through them completely (tons of varnish and gunk throughout), cleaned everything thoroughly, double-checked the jets to make sure they are clear, drained the gas tank and put in fresh gas. Re-installed everything. Fired it up. it would start, but ran pretty rough. Took out out for a test spin, it took some coaxing to get the RPMs up, and then had absolutely abysmal power, died at idle, even with the choke on. Tried adjusting the pilot screws out from 2 1/2 turns, could not get any better results. Tore down the carbs again just to be sure there was no blockage (didn't find anything), followed a breakdown diagram when rebuilding, I'm 99% sure they are back together correctly. This time around, I adjusted the idle up to above 3K RPMs to make it die less. I think I also managed to do something different when I put it back together, because it seems to run better. It now has good throttle response and power at > 3K RPMs as long as the choke is on, although it "seeks" a little while idling, but does not die. However, as soon as I touch the choke, even halfway, the RPMs start to drop down to a chug, then it dies within 3-5 seconds of touching the choke. I also checked the left side spark plug, it looked fine (no black or white buildup) so I didn't bother pulling the right. It must be running lean right? Or possibly a vacuum leak as well? I'm going to replace all the hoses tomorrow, and remove the California emissions garbage (plugging and re-routing per a guide I found on this forum). I haven't messed with the pilot screws much yet because it's nearly impossible for me to get my hands in there and adjust them, I just left them at about 2 3/4 turns. Does anyone have reccomendations for how to adjust those damn things more easily? If anyone can give me some suggestions for possible fixes to try, I would greatly appreciate it.

September 29th, 2014, 09:14 PM	#2
csmith12 The Corner Whisperer Name: Chris (aka Reactor) Location: Northern KY Join Date: May 2011 Motorcycle(s): 2010 250 (track), 1992 250, 2006 R6 (street/track), 2008 R6 (track) Posts: Too much. MOTY 2015, MOTM - Nov '12, Nov '13	Welcome John! Don't just throw parts at it. To check for a vac leak, spritz some carb cleaner around things and listen for idle changes. But first... I assume you checked the air box right? And... it seems as of late, bugs have been infesting bike's snorkle tubes. So don't forget to check that too. __________________________________________________ Goal: Shake A Million Hands \| Look through the corners \| Track Day Prep \| Closest track? \| The Mid-Ohio School

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September 29th, 2014, 09:32 PM	#3
jonnybravo9 ninjette.org newbie Name: John Location: Los Angeles Join Date: Sep 2014 Motorcycle(s): 2009 Ninja 250, 2001 Honda CBR F4i Posts: 4	Thanks Chris! I'm not sure what you mean by "checked the air box"? As in for wasp nests and crap? I did open up the side, filter looks clean, I didn't notice anything unusual. Where all should I check elsewise? Did a quick bit of googling but cannot find the snorkel tube location? Although the bugs out here in SoCal are generally not too bad. Edit: Will do the carb cleaner check, you're supposed to hit all the connection points for the vacuum fittings and intake connections, right?

September 29th, 2014, 10:00 PM	#5
jonnybravo9 ninjette.org newbie Name: John Location: Los Angeles Join Date: Sep 2014 Motorcycle(s): 2009 Ninja 250, 2001 Honda CBR F4i Posts: 4	Got it! Will do tomorrow and post a follow up

September 30th, 2014, 02:03 AM	#6
choneofakind ninjette.org certified postwhore Name: . Location: . Join Date: Feb 2011 Motorcycle(s): . Posts: Too much. MOTM - Feb '13, Feb '14	It has sat for a year. Pour the correct amount of carb cleaner in with the gas and ride that thing for an hour hard. It will help.

October 2nd, 2014, 09:17 PM	#7
jonnybravo9 ninjette.org newbie Name: John Location: Los Angeles Join Date: Sep 2014 Motorcycle(s): 2009 Ninja 250, 2001 Honda CBR F4i Posts: 4	Hey, so I finally had time to mess with it today (crazy week at work). Airbox and snorkel tubes are clean. I discovered that my boots between the airbox and carbs, and also between the carbs and engine block were not seated right. Got everything seated and fired it up, still running as I described, but seemed a bit better. After spraying bursts of carb cleaner around, I narrowed it down to the spot shown in the picture below (sorry for quality). Spritzing a burst at site 1 seems to produce the largest rev. Sites 2 and 3 produce medium ish revs. All other locations get nothing. I'm guessing it's the boot between the carb and engine that isn't sealed properly. I don't know what else it would be.... I tightened the clamps as much as possible on the boot and that didn't make a difference. I don't see how I could have managed it, but maybe I screwed up the boot when installing it and damaged it somehow. Any ideas before I order a new one and slap it on there? carb.png