'07 250 running one cylinder

regelbrecha · February 23rd, 2013, 01:27 PM

Hi guys,

Last summer I bought my '07 250 at 6700 miles. I'm at 10,500 now after a lot of off season riding and a grueling 11 hour trip from midcoast Maine to Rochester.
The bike started losing power intermittantly in the right cylinder a couple of months ago, only a little at first but now it's predominantly running on the left cylinder alone. I've taken the carbs off, cleaned them, checked the air and fuel filter changed the plugs and oil.
The fuel is getting to the carbs, and the bike starts fine so I should have compression. The bike will sometimes catch in both cylinders for 20 seconds or so, then it will die back down and the revs will be slow to climb. Additionally, the left cylinder plug looks a healthy brown but the right is black with buildup. Could this be a valve thing?

I guess I'm asking if any of you have had similar or identical problems, and if so what the best method of diagnosis would be. I'm going out to check the spark right now, just trying not to lose momentum. I've been stumped with this problem for the past two months

Kevin H · February 23rd, 2013, 02:12 PM

I had the same problem,it was a bad coil. You could test yours by swapping coils from one cylinder to the other. I picked up a set on ebay.

FvnnyL3tt3r1ng · February 23rd, 2013, 02:35 PM

Just had a very similar problem. Very possible it's a fuel flow issue. Since you are fine on one cylinder I would assume the fuel line into the carbs is fine. You might want to replace your float valves ($60 total from kneedraggers.com) if they haven't been replaced before.

You can open up the drain on the bowls and see how much fuel is coming into your bowls while you hold the starter button. Motofool told me it should be at least 2cc a second, which is basically a steady stream. When I ran my test one of my carbs was peeing just fine while the other was just barely dripping. Easy troubleshooting; you don't even have to remove plastics.

regelbrecha · March 4th, 2013, 10:02 PM

Hi again,
Sorry for the late reply and thanks for your ideas!

I checked the fuel flow first. Both carburators flow fule at the same rate from the flot bowl drains.

After seeing an intermittent spark I opted for a new coil off E-bay ($15). I went to install it today and found one of the terminals on the coil was seriously corroded (road salt) and the connection was loose

I't seems likely this could be an issue in other connections as well since the engine still ran on 1 cyl after the new coil unit.

Another reason I'm linking this to road salt is because it was running better after a rain. The bad connections conduct better when submerged in saltwater, whereas dry salt does not conduct electricity.

Will go over connections with sandpaper and then coat with small amounts of di-electric grease ASAP and post results (if any).
Posted via Mobile Device

regelbrecha · March 6th, 2013, 01:29 PM

Problem solved. After I fixed the coil terminals issue the bike's battery was too low to spark. I charged it overnight and got her up and running full power this morning. Thanks again!
Posted via Mobile Device

FvnnyL3tt3r1ng · March 7th, 2013, 02:11 PM

Quote:

Originally Posted by regelbrecha

Problem solved. After I fixed the coil terminals issue the bike's battery was too low to spark. I charged it overnight and got her up and running full power this morning. Thanks again!
Posted via Mobile Device

Great! hopefully the bike still charges normally though as batteries don't like to be discharged too much without breaking.

February 23rd, 2013, 01:27 PM	#1
regelbrecha ninjette.org newbie Name: kalle Location: 434 varnumville rd Join Date: Feb 2013 Motorcycle(s): '07 Ninja 250 Posts: 3	'07 250 running one cylinder Hi guys, Last summer I bought my '07 250 at 6700 miles. I'm at 10,500 now after a lot of off season riding and a grueling 11 hour trip from midcoast Maine to Rochester. The bike started losing power intermittantly in the right cylinder a couple of months ago, only a little at first but now it's predominantly running on the left cylinder alone. I've taken the carbs off, cleaned them, checked the air and fuel filter changed the plugs and oil. The fuel is getting to the carbs, and the bike starts fine so I should have compression. The bike will sometimes catch in both cylinders for 20 seconds or so, then it will die back down and the revs will be slow to climb. Additionally, the left cylinder plug looks a healthy brown but the right is black with buildup. Could this be a valve thing? I guess I'm asking if any of you have had similar or identical problems, and if so what the best method of diagnosis would be. I'm going out to check the spark right now, just trying not to lose momentum. I've been stumped with this problem for the past two months

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February 23rd, 2013, 02:12 PM	#2
Kevin H ninjette.org member Name: Kevin Location: NYC Join Date: Oct 2012 Motorcycle(s): 1997 Kawasaki EX 250, 1997 HD Road King, 1980 HD Sportster Posts: 14	I had the same problem,it was a bad coil. You could test yours by swapping coils from one cylinder to the other. I picked up a set on ebay.

February 23rd, 2013, 02:35 PM	#3
FvnnyL3tt3r1ng ninjette.org certified postwhore Name: Justin Location: Florida Join Date: Aug 2012 Motorcycle(s): Ninja 250 2001 Posts: A lot.	Just had a very similar problem. Very possible it's a fuel flow issue. Since you are fine on one cylinder I would assume the fuel line into the carbs is fine. You might want to replace your float valves ($60 total from kneedraggers.com) if they haven't been replaced before. You can open up the drain on the bowls and see how much fuel is coming into your bowls while you hold the starter button. Motofool told me it should be at least 2cc a second, which is basically a steady stream. When I ran my test one of my carbs was peeing just fine while the other was just barely dripping. Easy troubleshooting; you don't even have to remove plastics.

March 4th, 2013, 10:02 PM	#4
regelbrecha ninjette.org newbie Name: kalle Location: 434 varnumville rd Join Date: Feb 2013 Motorcycle(s): '07 Ninja 250 Posts: 3	Hi again, Sorry for the late reply and thanks for your ideas! I checked the fuel flow first. Both carburators flow fule at the same rate from the flot bowl drains. After seeing an intermittent spark I opted for a new coil off E-bay ($15). I went to install it today and found one of the terminals on the coil was seriously corroded (road salt) and the connection was loose I't seems likely this could be an issue in other connections as well since the engine still ran on 1 cyl after the new coil unit. Another reason I'm linking this to road salt is because it was running better after a rain. The bad connections conduct better when submerged in saltwater, whereas dry salt does not conduct electricity. Will go over connections with sandpaper and then coat with small amounts of di-electric grease ASAP and post results (if any). Posted via Mobile Device

March 6th, 2013, 01:29 PM	#5
regelbrecha ninjette.org newbie Name: kalle Location: 434 varnumville rd Join Date: Feb 2013 Motorcycle(s): '07 Ninja 250 Posts: 3	Problem solved. After I fixed the coil terminals issue the bike's battery was too low to spark. I charged it overnight and got her up and running full power this morning. Thanks again! Posted via Mobile Device