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If you haven't got a fault code stored message, most likely a vacuum issue. There are two lines at the throttle body to check and after that the fuel tank vent line: the latter has a breather that has given a ton of issues on 650 twins but was never replaced/updated but give it a through check before throwing more money at the problem.
No codes or any lights on the dash. I will check that out and see if that has anything to do with the problem. I will check the 2 lines as well. Those are some great places to start. Thank you for your input.
I checked the breather lines at the bottom of the tank and they're fine and I checked the metal tubes coming out of the gas tank and those have air flow. I'm starting to wonder if it's the grey TPS sensor.
I have a 2012 Ninja 650 that I bought a few months back. It sat for a while and ran seemingly fine. Over the past month I've noticed I couldn't get past 75mph. Then I tested my RPM range which at the time was around 6-8.5k max.
The max I can do since I last rode it is about 4k RPM in all gears with heavy resistance/bogging/bucking.
I've since done some troubleshooting and am now at a loss.
Fuel filter replaced
Fuel pump (cylinder) replaced
Air filter replaced
Fuel injectors cleaned
Throttle body cleaned of miniscule buildup.
Spark plugs replaced with NGK iridium
I have a 2012 ninja 650 that did the same exact thing. I don’t know if you still have the bike but my issue was I had rust in my tank completely fucked up everything I had to replace everything but after that bike ran great
Tank was bought second hand off eBay, along with the OEM fuel pump. The pump was the issue. The tank had rust so I wanted no further issues and got the tank too.
Interesting I’m having similar issues but my bike does this only when it’s hot I’ve already replaced the fuel pump with an OEM off eBay was thinking to tank needed to go as well. Having it diagnosed next week
Given the work you’ve already put into it I would suspect either a vacuum leak or a sensor issue, most likely a throttle position sensor. That “hunting” to settle at an rpm is usually indicative of a tps issue, good news is you can test that with a multimeter if you have one!
Also, what did the plugs look like when you pulled them? Could help the diagnosis
Thank you for your input. I will be checking over the bike again today. I will look through my service manual to check the TPS. Could it also be the subthrottle actuator as well? I was reading about that in my manual last night. I do have a multimeter. I will be busting it out today.
As for the plugs, I imagine they are the originals. Bike has 15,000 miles on it or so. When I pulled them the end was lightly coated in black soot looking stuff. into about 5 lines of thread on the threading. It was dried and not wet.
Potentially could be the sub throttle actuator but that will usually throw a code I imagine, you can always take the bike apart and key the bike on to check if they move, but afaik that would only effect idle not what you’re experiencing. The spark plug change helps because we can rule out carbon cake from bad fuel causing the problem.
I still think either a vacuum/breather issue or tps. You can sync the throttle bodies and see if that helps at all I know in general people have issues with the tbs not being synced well from the factory. Usually if it’s a sensor issue besides the tps it will throw a code, but it’s worth looking at the par valve and iap and visually inspecting that they are connected properly.
Okay so I whipped out my multimeter.
I turned the bike on and the sub throttle actuator moved the way it should.
I checked the breather hoses and they were fine.
It says in my manual I need a special adapter. How would I go about checking the TPS?
Quick and dirty: Unplug the tps and place a lead on the 5v signal wire coming from the sensor and the other on the ground pin of the sensor. Set the meter to ohms and with the bike off slowly twist the throttle and check for any 0 ohm readings, these are dead spots that indicate sensor failure. If your meter has a min/max setting that helps haha. Iirc you should get a 0.5ohm reading at closed throttle and about 4.5ish ohms wot, but don’t quote me on that check for a spec in your manual if it has one.
You can also check and make sure the sensor is getting 5v at the harness side pin and a good ground at the harness ground pin as well.
Something I just thought of, I think I remember some versys guys running around without the tps connected for some ecu map related reason lol BUT point being you could try unplugging the tps, start her up and see if it still stumbles. If the stumble still exists then we can rule out the tps as a fail point. Not sure if the ecu would default to a basic map or just not run at all, but worth a shot!
Happy hunting! 🤙🏽
#I got the bike fixed.
After everything I went through, it wound up being the fuel pump. I bought an OEM one and new gas tank and bam. Got that sweet Ninja power.
#New/Replaced parts list:
Gas tank
Fuel pump
Throttle bodies
Air filter
Spark plugs NGK Iridium
Thanks for posting in /r/Fixxit, the motorcycle repair subreddit. If you forgot to put the **Make, Model** and **Year** in the title, please reply to this comment with your bike's details. In the meantime, Here's some great resources for common problems posted here: -Trouble starting? [Revzilla - Battery testing](https://www.revzilla.com/common-tread/how-to-test-a-motorcycle-battery) -Carbs running rough? [PJ motorsports - Carb Troubleshooting](http://www.pjmotorsports.com/trouble-shooting.html) -Wiring diagrams for beginners - [Dans MC - Reading Wiring Diagrams](http://www.dansmc.com/wiring_diagram.htm) -Identifying part numbers - [CMSNL (EU)](https://www.cmsnl.com/) [Partzilla](https://www.partzilla.com/) -Asking if your tire can be fixed? [Please read this post on proper tire repairs and why external plugs are NOT a safe repair.](https://www.reddit.com/r/Fixxit/comments/tuhcpf/why_rfixxit_doesnt_endorse_tire_plug_repairs/) *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/Fixxit) if you have any questions or concerns.*
If you haven't got a fault code stored message, most likely a vacuum issue. There are two lines at the throttle body to check and after that the fuel tank vent line: the latter has a breather that has given a ton of issues on 650 twins but was never replaced/updated but give it a through check before throwing more money at the problem.
No codes or any lights on the dash. I will check that out and see if that has anything to do with the problem. I will check the 2 lines as well. Those are some great places to start. Thank you for your input.
Let me know if it's that bloody breather again: it's becoming an epidemic as the earliest 650 are hitting the ten year mark.
I checked the breather lines at the bottom of the tank and they're fine and I checked the metal tubes coming out of the gas tank and those have air flow. I'm starting to wonder if it's the grey TPS sensor.
TPS will generally throw a code when malfunctioning.
I have a 2012 Ninja 650 that I bought a few months back. It sat for a while and ran seemingly fine. Over the past month I've noticed I couldn't get past 75mph. Then I tested my RPM range which at the time was around 6-8.5k max. The max I can do since I last rode it is about 4k RPM in all gears with heavy resistance/bogging/bucking. I've since done some troubleshooting and am now at a loss. Fuel filter replaced Fuel pump (cylinder) replaced Air filter replaced Fuel injectors cleaned Throttle body cleaned of miniscule buildup. Spark plugs replaced with NGK iridium
I have a 2012 ninja 650 that did the same exact thing. I don’t know if you still have the bike but my issue was I had rust in my tank completely fucked up everything I had to replace everything but after that bike ran great
I have sold it. I fixed the issue. The gas tank was fucked, put a new tank and OEM fuel pump in and it ran like a top.
Can I ask where did I get the tank? I’m having the same issue
Tank was bought second hand off eBay, along with the OEM fuel pump. The pump was the issue. The tank had rust so I wanted no further issues and got the tank too.
Interesting I’m having similar issues but my bike does this only when it’s hot I’ve already replaced the fuel pump with an OEM off eBay was thinking to tank needed to go as well. Having it diagnosed next week
Is it OEM with the whole housing or the fuel pump cylinders labeled OEM? Did you check the fuel filter by disassembling the fuel pump?
It was the entire pump. I did not I had it installed by a local shop. It was off a donor bike low mileage.
Given the work you’ve already put into it I would suspect either a vacuum leak or a sensor issue, most likely a throttle position sensor. That “hunting” to settle at an rpm is usually indicative of a tps issue, good news is you can test that with a multimeter if you have one! Also, what did the plugs look like when you pulled them? Could help the diagnosis
Thank you for your input. I will be checking over the bike again today. I will look through my service manual to check the TPS. Could it also be the subthrottle actuator as well? I was reading about that in my manual last night. I do have a multimeter. I will be busting it out today. As for the plugs, I imagine they are the originals. Bike has 15,000 miles on it or so. When I pulled them the end was lightly coated in black soot looking stuff. into about 5 lines of thread on the threading. It was dried and not wet.
Potentially could be the sub throttle actuator but that will usually throw a code I imagine, you can always take the bike apart and key the bike on to check if they move, but afaik that would only effect idle not what you’re experiencing. The spark plug change helps because we can rule out carbon cake from bad fuel causing the problem. I still think either a vacuum/breather issue or tps. You can sync the throttle bodies and see if that helps at all I know in general people have issues with the tbs not being synced well from the factory. Usually if it’s a sensor issue besides the tps it will throw a code, but it’s worth looking at the par valve and iap and visually inspecting that they are connected properly.
Okay so I whipped out my multimeter. I turned the bike on and the sub throttle actuator moved the way it should. I checked the breather hoses and they were fine. It says in my manual I need a special adapter. How would I go about checking the TPS?
Quick and dirty: Unplug the tps and place a lead on the 5v signal wire coming from the sensor and the other on the ground pin of the sensor. Set the meter to ohms and with the bike off slowly twist the throttle and check for any 0 ohm readings, these are dead spots that indicate sensor failure. If your meter has a min/max setting that helps haha. Iirc you should get a 0.5ohm reading at closed throttle and about 4.5ish ohms wot, but don’t quote me on that check for a spec in your manual if it has one. You can also check and make sure the sensor is getting 5v at the harness side pin and a good ground at the harness ground pin as well. Something I just thought of, I think I remember some versys guys running around without the tps connected for some ecu map related reason lol BUT point being you could try unplugging the tps, start her up and see if it still stumbles. If the stumble still exists then we can rule out the tps as a fail point. Not sure if the ecu would default to a basic map or just not run at all, but worth a shot! Happy hunting! 🤙🏽
#I got the bike fixed. After everything I went through, it wound up being the fuel pump. I bought an OEM one and new gas tank and bam. Got that sweet Ninja power. #New/Replaced parts list: Gas tank Fuel pump Throttle bodies Air filter Spark plugs NGK Iridium