You got me on this one...?

Olie · May 19th, 2014, 03:34 PM

I spent the weekend tearing apart the bike to remove the carbs for cleaning, remove the clean air and CA emissions stuff, install the Dynojet kit that came with my Area P exhaust. All went well, test rides were AWESOME and everything seemed fine. Washed her up and parked in the garage for work this morning. I did go back out last night to re-torque the exhaust flange bolts but other than that did nothing else.

Go out this morning and she starts right up. Let it warm for a minute and take off. A block or two into the ride, starts to feel really sluggish. Couple of more blocks and it dies all together. Try starting with no luck. Finally, I put the choke on and am able to get it started but as soon as I reduce the choke it dies again. I limp her home. Run to work to check in then back to try and figure out what is going on. At first I think maybe one of the vacuum lines popped off but they are looking good. So, I start going through in my head anything I did after the last time it ran correctly and the only things were wash and torqued the exhaust nuts. Thinking the water may have gotten into the airbox, I open it up. A little water but nothing major. I start it up again with the choke and just let it run to see what will happen. After a few minutes I turn the choke off and it now holds idle fine and runs like normal.

So, my only guess is that water did get in the airbox or carbs when I washed the bike and it just needed to burn it off. Rode back to work and then home for lunch with no problems.

What a way to start a Monday morning. Any thoughts on what else I should check to make sure all is good?

alex.s · May 19th, 2014, 03:41 PM

sounds like there was something stuck in a pilot jet. i wouldn't worry about it if its running well now. put a better fuel filter on next time you take the fuel system apart

mgentz · May 19th, 2014, 04:00 PM

I was going to guess a water issue.

Olie · May 20th, 2014, 11:16 AM

Well, happened again this morning. Starts right up and idles fine, only gave a couple of minutes for warm up but no choke was needed. Blipped the throttle a couple of times and engine raced and idled down just fine. Rode a couple of blocks and started bogging down then died. Full choke to restart, let it run for a minute or two and then rode just fine. Did my workout for 1 1/2 hours, started up again without choke and ran fine on the ride home.

If it was a clogged pilot jet, wouldn't it not hold idle at all? The warming it up part has me confused. Seems to only happen after sitting overnight and symptoms come on several minutes into the ride. Nothing funnier than a bald guy scratching his head...

alex.s · May 20th, 2014, 11:34 AM

sounds like your float valve is getting stuck closed. or maybe the petcock

mgentz · May 20th, 2014, 11:35 AM

try draining the carb bowls. fuel floats on water but once you get into the needle jet or main jet you start to pull water and the bike dies. Thus, riding it would put you in this circuit versus idle which uses the air and pilot jets. (there are other things working in the carb, but lets keep it simple here)

seriously, drain the bowls.

DaBlue1 · May 20th, 2014, 11:47 AM

What is your idle speed set at?
At what rpms did it start to bog?
Any external fuel filters on the bike?
Tank venting properly?

cbinker · May 20th, 2014, 12:52 PM

i was thinking Idle screw, but water makes sense too.

jeffb502 · May 20th, 2014, 01:02 PM

Did you get aggressive with the water and maybe get some in the spark plug wells? Do these bikes use a coil on plug type system? I haven't needed to look so I'm not sure, but a quick google search for "ninja 250 coil on plug" resulted in some pictures of a coil on plug type system popping up.

On Crown Vics and other similar Fords it was pretty common for people to get a little aggressive with washing under the hood, and water in the coils/spark plug wells would cause rough running for an 8 cylinder engine. I imagine the same problem in a 2 cylinder engine could make it stall. The coils on the Fords were known to work intermittently before going completely dead.

Olie · May 20th, 2014, 01:23 PM

Quote:

Originally Posted by alex.s

sounds like your float valve is getting stuck closed. or maybe the petcock

I started thinking about this also...good advice.

Quote:

Originally Posted by mgentz

try draining the carb bowls. fuel floats on water but once you get into the needle jet or main jet you start to pull water and the bike dies. Thus, riding it would put you in this circuit versus idle which uses the air and pilot jets. (there are other things working in the carb, but lets keep it simple here)

seriously, drain the bowls.

On the list for this afternoon, I'm starting to wonder if after cleaning the carbs the float valves aren't working correctly. Thanks for the suggestions.

Quote:

Originally Posted by DaBlue1

What is your idle speed set at?
At what rpms did it start to bog?
Any external fuel filters on the bike?
Tank venting properly?

I set it just under 1500 RPM and it's stable there.
The two times it has happened the RPMs were at different levels but I would say it was under load at approx. 5000 RPM. Weird thing is when revving the engine this morning it was good up to about 8000.
No additional fuel filters
I did remove the clean air system and CA emissions stuff. On the side of the tank, I capped off the two ports and left the overflow drain connected. I want to say the two color coded red and blue leaving the white connected.

Skullz · May 20th, 2014, 01:56 PM

Since the only two things you did were to wash and tighten the bolts.
My guess would be water in the gas, check your gasket on the gas cap and see if something is wrong with it, and get some heet gas treatment to make the water mix with the gas.
If the problem persist after that then i would look into something going on with the carbs and maybe tear back into them to find the source of the problem.

Olie · May 20th, 2014, 07:23 PM

Latest update:
Drained the bowls and all is clean.

Checked float level and it's close, left I think is a little high. Manual says .5-1mm above mating surface but it doesn't say where on the carb. If you go forward then it is above and towards the back it's below so I'm guessing middle of the bowl. Left seems a bit high so I might try to adjust.

Here's what I think the problem is. When setting the petcock to PRI, the bowls emptied but didn't keep flowing from the tank. So I popped the cap open and fuel flowed again.

Here is my question:
Does the tank vent in air through the cap? I know it's suppose to let off pressure but does it allow air in when the fuel level lowers creating a vacuum?

DaBlue1 · May 20th, 2014, 07:43 PM

Quote:

Originally Posted by Olie

Here is my question:
Does the tank vent in air through the cap? I know it's suppose to let off pressure but does it allow air in when the fuel level lowers creating a vacuum?

I've taken the gas cap completely apart. There is a one way valve in the cap so only pressure comes out. There is a fuel tank breather hose connected to the top of the tank just underneath the left fairing that runs to the back of the bike (49 States model). There are a couple of places where it could possibly be pinched.

Olie · May 20th, 2014, 07:58 PM

Quote:

Originally Posted by DaBlue1

I've taken the gas cap completely apart. There is a one way diaphragm in the cap so only pressure comes out. There is a fuel tank breather hose connected to the top of the tank just underneath the left fairing that runs to the back of the bike. There are a couple of places where it could possibly be pinched.

I have the CA model so the tank has 3 ports at the tank. White is the overflow tube, blue and red hoses went to the separator for the clean air system. Using some compressed air, I figured out the red is under the seal of the gas cap and the blue is what goes to the vent in the cap located near the hinge. My guess is I need to leave open the red line allowing air to fill into the tank when a vacuum is created. Because the separator is gone, I should be able to leave the blue port capped as there's nothing on the other end.

DaBlue1 · May 20th, 2014, 08:20 PM

Quote:

Originally Posted by Olie

I have the CA model so the tank has 3 ports at the tank. White is the overflow tube, blue and red hoses went to the separator for the clean air system. Using some compressed air, I figured out the red is under the seal of the gas cap and the blue is what goes to the vent in the cap located near the hinge. My guess is I need to leave open the red line allowing air to fill into the tank when a vacuum is created. Because the separator is gone, I should be able to leave the blue port capped as there's nothing on the other end.

I believe it's the blue one you leave open. Either way, your on the right track.

Olie · May 20th, 2014, 08:33 PM

Did some testing. Capped both red and blue, drained fuel through the bowl until it created enough of a vacuum to stop flow. Popped the red cap and I could hear the suction as soon as the cap came off and fuel flowed again. Opened the gas cap and no suction sound from there. Repeated the vacuum lock and then popped the blue cap. Couldn't hear the suction of air in but fuel flowed again. Opened the gas cap and then I could hear the suction of air as the cap opened.

So it seems I have found my issue, now the question is which port to leave open. It is obvious the red one vents into the tank below the cap seal as the blue vent above the seal. My first guess would be to say leave the red open but then I worry about fuel getting into the line when the tank is full. As I read others posts, they seem to have had success with leaving the blue port open but it makes me wonder if that is creating a slight negative pressure in the system. Is this better than a free flowing fuel supply? Wouldn't the float valves control the amount of fuel in the bowls?

DaBlue1 · May 20th, 2014, 08:56 PM

Quote:

Originally Posted by Olie

.... Is this better than a free flowing fuel supply? Wouldn't the float valves control the amount of fuel in the bowls?

Yes the floats control the amount of fuel in the bowls. It's not a free flowing system unless you put the petcock on PRI. The 49 States model tank operate basically the same way except with one less hose.

Olie · May 20th, 2014, 09:31 PM

Maybe I shouldn't have used "free flowing system" in my last post. I guess what I'm asking is with the blue line open it still leaves a vacuum or negative pressure in the tank as the red line open allows air to enter unrestricted. Which would be better, a slight negative pressure or basically zero pressure? Am I making sense...in my head it does but my fat, old man fingers won't type what I'm thinking!!!

May 19th, 2014, 03:34 PM	#1
Olie New Old Guy Name: Olie Location: Oahu, Hawaii Join Date: Mar 2014 Motorcycle(s): 2011 250R SE Posts: 57 Blog Entries: 1	You got me on this one...? I spent the weekend tearing apart the bike to remove the carbs for cleaning, remove the clean air and CA emissions stuff, install the Dynojet kit that came with my Area P exhaust. All went well, test rides were AWESOME and everything seemed fine. Washed her up and parked in the garage for work this morning. I did go back out last night to re-torque the exhaust flange bolts but other than that did nothing else. Go out this morning and she starts right up. Let it warm for a minute and take off. A block or two into the ride, starts to feel really sluggish. Couple of more blocks and it dies all together. Try starting with no luck. Finally, I put the choke on and am able to get it started but as soon as I reduce the choke it dies again. I limp her home. Run to work to check in then back to try and figure out what is going on. At first I think maybe one of the vacuum lines popped off but they are looking good. So, I start going through in my head anything I did after the last time it ran correctly and the only things were wash and torqued the exhaust nuts. Thinking the water may have gotten into the airbox, I open it up. A little water but nothing major. I start it up again with the choke and just let it run to see what will happen. After a few minutes I turn the choke off and it now holds idle fine and runs like normal. So, my only guess is that water did get in the airbox or carbs when I washed the bike and it just needed to burn it off. Rode back to work and then home for lunch with no problems. What a way to start a Monday morning. Any thoughts on what else I should check to make sure all is good?

May 19th, 2014, 03:41 PM	#2
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	sounds like there was something stuck in a pilot jet. i wouldn't worry about it if its running well now. put a better fuel filter on next time you take the fuel system apart __________________________________________________

May 20th, 2014, 11:34 AM	#5
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	sounds like your float valve is getting stuck closed. or maybe the petcock __________________________________________________

May 20th, 2014, 12:52 PM	#8
cbinker Track Clown Name: Chris Location: Kingman, AZ Join Date: May 2012 Motorcycle(s): '08 250R, 21 MV F3 800, Kawasaki 400 build Posts: A lot. MOTM - Sep '15	i was thinking Idle screw, but water makes sense too. __________________________________________________ TEAM ALFALFA www.apexassassins.com

May 19th, 2014, 04:00 PM	#3
mgentz Board Member Name: ... Location: WI Join Date: Dec 2011 Motorcycle(s): 250R (street), 250R (dirt) Posts: A lot.	I was going to guess a water issue.

May 20th, 2014, 11:16 AM	#4
Olie New Old Guy Name: Olie Location: Oahu, Hawaii Join Date: Mar 2014 Motorcycle(s): 2011 250R SE Posts: 57 Blog Entries: 1	Well, happened again this morning. Starts right up and idles fine, only gave a couple of minutes for warm up but no choke was needed. Blipped the throttle a couple of times and engine raced and idled down just fine. Rode a couple of blocks and started bogging down then died. Full choke to restart, let it run for a minute or two and then rode just fine. Did my workout for 1 1/2 hours, started up again without choke and ran fine on the ride home. If it was a clogged pilot jet, wouldn't it not hold idle at all? The warming it up part has me confused. Seems to only happen after sitting overnight and symptoms come on several minutes into the ride. Nothing funnier than a bald guy scratching his head...

May 20th, 2014, 11:35 AM	#6
mgentz Board Member Name: ... Location: WI Join Date: Dec 2011 Motorcycle(s): 250R (street), 250R (dirt) Posts: A lot.	try draining the carb bowls. fuel floats on water but once you get into the needle jet or main jet you start to pull water and the bike dies. Thus, riding it would put you in this circuit versus idle which uses the air and pilot jets. (there are other things working in the carb, but lets keep it simple here) seriously, drain the bowls.

May 20th, 2014, 11:47 AM	#7
DaBlue1 Long Time Rider Name: Blue Location: Charlotte, NC Join Date: Sep 2010 Motorcycle(s): 2009 Kawasaki Ninja 250R Posts: A lot.	What is your idle speed set at? At what rpms did it start to bog? Any external fuel filters on the bike? Tank venting properly?

May 20th, 2014, 01:02 PM	#9
jeffb502 ninjette.org guru Name: Jeff Location: Santa Maria, CA Join Date: Oct 2013 Motorcycle(s): 2013 White Ninja 300, 2010 Red Ninja 250r (Sold) Posts: 335	Did you get aggressive with the water and maybe get some in the spark plug wells? Do these bikes use a coil on plug type system? I haven't needed to look so I'm not sure, but a quick google search for "ninja 250 coil on plug" resulted in some pictures of a coil on plug type system popping up. On Crown Vics and other similar Fords it was pretty common for people to get a little aggressive with washing under the hood, and water in the coils/spark plug wells would cause rough running for an 8 cylinder engine. I imagine the same problem in a 2 cylinder engine could make it stall. The coils on the Fords were known to work intermittently before going completely dead.

May 20th, 2014, 01:56 PM	#11
Skullz ninjette.org guru Name: Ray Location: 48162 Join Date: Aug 2013 Motorcycle(s): 2012 Ninja 250 Posts: 450	Since the only two things you did were to wash and tighten the bolts. My guess would be water in the gas, check your gasket on the gas cap and see if something is wrong with it, and get some heet gas treatment to make the water mix with the gas. If the problem persist after that then i would look into something going on with the carbs and maybe tear back into them to find the source of the problem.

May 20th, 2014, 07:23 PM	#12
Olie New Old Guy Name: Olie Location: Oahu, Hawaii Join Date: Mar 2014 Motorcycle(s): 2011 250R SE Posts: 57 Blog Entries: 1	Latest update: Drained the bowls and all is clean. Checked float level and it's close, left I think is a little high. Manual says .5-1mm above mating surface but it doesn't say where on the carb. If you go forward then it is above and towards the back it's below so I'm guessing middle of the bowl. Left seems a bit high so I might try to adjust. Here's what I think the problem is. When setting the petcock to PRI, the bowls emptied but didn't keep flowing from the tank. So I popped the cap open and fuel flowed again. Here is my question: Does the tank vent in air through the cap? I know it's suppose to let off pressure but does it allow air in when the fuel level lowers creating a vacuum?

May 20th, 2014, 08:33 PM	#16
Olie New Old Guy Name: Olie Location: Oahu, Hawaii Join Date: Mar 2014 Motorcycle(s): 2011 250R SE Posts: 57 Blog Entries: 1	Did some testing. Capped both red and blue, drained fuel through the bowl until it created enough of a vacuum to stop flow. Popped the red cap and I could hear the suction as soon as the cap came off and fuel flowed again. Opened the gas cap and no suction sound from there. Repeated the vacuum lock and then popped the blue cap. Couldn't hear the suction of air in but fuel flowed again. Opened the gas cap and then I could hear the suction of air as the cap opened. So it seems I have found my issue, now the question is which port to leave open. It is obvious the red one vents into the tank below the cap seal as the blue vent above the seal. My first guess would be to say leave the red open but then I worry about fuel getting into the line when the tank is full. As I read others posts, they seem to have had success with leaving the blue port open but it makes me wonder if that is creating a slight negative pressure in the system. Is this better than a free flowing fuel supply? Wouldn't the float valves control the amount of fuel in the bowls?

May 20th, 2014, 09:31 PM	#18
Olie New Old Guy Name: Olie Location: Oahu, Hawaii Join Date: Mar 2014 Motorcycle(s): 2011 250R SE Posts: 57 Blog Entries: 1	Maybe I shouldn't have used "free flowing system" in my last post. I guess what I'm asking is with the blue line open it still leaves a vacuum or negative pressure in the tank as the red line open allows air to enter unrestricted. Which would be better, a slight negative pressure or basically zero pressure? Am I making sense...in my head it does but my fat, old man fingers won't type what I'm thinking!!!