• Welcome to the new GTAM. Have a look around and please post any issues in the Support Forum. Be sure to check out your profile settings to confirm all your settings.

Bike does not rev past 2-3K

Ghostrider619

Well-known member
Buddy's Ninja 300 does not rev past 2-3K. Bike bounces off 2-3K when you twist the throttle wide open.
It sounds exactly like when a bike has the pit lane limiter on or launch control on.
Anything that he should look at before he takes it to a mechanic ?
 

TK4

Well-known member
Buddy's Ninja 300 does not rev past 2-3K. Bike bounces off 2-3K when you twist the throttle wide open.
It sounds exactly like when a bike has the pit lane limiter on or launch control on.
Anything that he should look at before he takes it to a mechanic ?
Throttle position sensor - the service manual should have specs.
 

boyoboy

Well-known member
Interesting thread. TK4 Im curious about your choice of checking the TPS. Was the OP's description of the bike bouncing off 2-3k revs what made you think TPS? I really have no idea, but I would like to know a bit more of your thinking on this issue (as a free tech lesson lol) thx.
 

GreyGhost

Well-known member
Site Supporter
My thoughts would be since it sounds like active control of the RPM, the computer is annoyed about something. What inputs would force the computer into active protection? No TPS signal makes sense, low oil pressure could also make sense but I don't know if that is monitored. If it just made no power, I would lean towards an ignition or fueling issue.
 

TK4

Well-known member
Interesting thread. TK4 Im curious about your choice of checking the TPS. Was the OP's description of the bike bouncing off 2-3k revs what made you think TPS? I really have no idea, but I would like to know a bit more of your thinking on this issue (as a free tech lesson lol) thx.
If the TPS fails, the ECU may think its running at full throttle and shut down the fuel pump.
If the fuel pump is ticking when the key is turned on that's not likely at fault.
I believe there are resistance values in the service manual, the only problem is that the part isn't sold separately - you'd have to replace the entire throttle body.
 

jeff96

Well-known member
If the ECU thinks the rev limit is being reached, I wouldn't have thought it would touch the fuel pump. Wouldn't it limit the revs by grounding the ignition temporarily? Is there a procedure to read trouble codes on the 'dash' display?
 

TK4

Well-known member
If the ECU thinks the rev limit is being reached, I wouldn't have thought it would touch the fuel pump. Wouldn't it limit the revs by grounding the ignition temporarily? Is there a procedure to read trouble codes on the 'dash' display?
It likely does both, to save on potential motor damage. I'm not hip to whether or not there's a trouble code readout, best get the factory service manual to find out.
 

TK4

Well-known member
It likely does both, to save on potential motor damage. I'm not hip to whether or not there's a trouble code readout, best get the factory service manual to find out.
I just did some checking, and I'm fairly certain you'll have to hook it up to the Kawasaki Diagnostic System software.
 

Robbo

Well-known member
Did your buddy unhook the battery for 10 mins and hook it back up...see if the problem is still there?

Costs nothing.


Sent from my iPhone using Tapatalk
 

FJRgeezer

Well-known member
I would definitely suggest you get the bike connected to whatever is kawasaki’s version of a code reader. I know from unfortunate personal experience that if the ecu has gone into “protection “ mode, which sounds like what you are describing, there are all kinds of things that can cause the ecu to try and “protect” the motor. Most of them not very serious, as an example a failing engine coolant temp. sensor, or a coolant pressure sensor. Get the codes pulled before you spend a bunch of unnecessary money, at least that’s what I would do.
 

boyoboy

Well-known member
Did your buddy unhook the battery for 10 mins and hook it back up...see if the problem is still there?

Costs nothing.


Sent from my iPhone using Tapatalk
Interesting thought. and easy to do for free. I like free. Let us know OP? Maybe check for corrosion in plugs/wiring while you are disconnecting the battery?
 
Last edited:

Brian P

Well-known member
Moderator
Site Supporter
It's more likely that the TPS is indicating that the throttle is shut all the time. When the throttle actually is shut (at idle), it idles OK, but if you try to open it, the engine gets more air but not more fuel ... resulting in sputtering and missing from the excessively lean situation.

The KDS is the official way to diagnose this, but the shop manual should have a procedure for checking the TPS with a voltmeter. On a bike that has a PowerCommander installed, you can simply go into the PC software with the engine running to see what it reports for TPS.

If it turns out that the TPS is bad, the official repair procedure is to replace the entire throttle body assembly. Kawasaki doesn't trust anyone with adjusting (or replacing) the TPS. The TPS is an off the shelf part from a supplier, which ought to be able to be tracked down, and I wouldn't be surprised one bit if many bikes and cars use the same one.
 

bitzz

Well-known member
Did your buddy unhook the battery for 10 mins and hook it back up...see if the problem is still there?

Costs nothing.


Sent from my iPhone using Tapatalk
That would be a "soft" reset and won't do much.

Do a "hard" reset by disconnecting the positive battery terminal and touching it to the negative terminal for a few seconds.
That will flatten all the capacitors and force the ECU into learn mode.

TPS is easy to test.
Three wire: Check you have 5 volt input and good ground reference. Measure the voltage output. Zero is a dead sensor. Output should vary with throttle movement, from somewhere over zero (usually one volt) to a high of 5 volts.
Two wire: test resistance across the sensor. Zero or infinite is a dead sensor. The resistance should vary with throttle movement.
 

Robbo

Well-known member
That would be a "soft" reset and won't do much.

Do a "hard" reset by disconnecting the positive battery terminal and touching it to the negative terminal for a few seconds.
That will flatten all the capacitors and force the ECU into learn mode.

TPS is easy to test.
Three wire: Check you have 5 volt input and good ground reference. Measure the voltage output. Zero is a dead sensor. Output should vary with throttle movement, from somewhere over zero (usually one volt) to a high of 5 volts.
Two wire: test resistance across the sensor. Zero or infinite is a dead sensor. The resistance should vary with throttle movement.
Never owned a bike with an ecu so didn’t want to recommend anything beyond my comfort level.

Thanks for stepping in and providing some more specific and relevant guidance/advice .


Sent from my iPhone using Tapatalk
 

Rob

Well-known member
Any flashing lights or check engine warnings on? Is bad fuel a possibility? An engine can idle ok with bad fuel and poor spark but once a load is added these things need to step up on their delivery.
Sounds like a possible mis-fire. Check to ensure plug boots are connected tightly and there is no moisture. Check plug conditions. Attach photos and even better a video of the bike doing what it is doing.
 

Mad Mike

Well-known member
For a Ninja 300, there are a few things to check:

If the bike is 2013, there is a ECU recall. This may be your problem as it presents like this.

Next, check the battery. If the battery and charging circuit is OK AND there is an ECU detected fault, a little yellow light will appear on upper right of the cluster. If the battery or charging circuit is failing, the ECU will not light the check engine lamp however the ECU will still store the service code. Make sure ignition is off when you test fuel injection sensors/controls otherwise the ECU will see them as faulty AND will record those fault codes until you reset the ECU.

Note:

Try self Self Diag mode:
- turn ignition on (don't start)
- press the left button on the dash until the cluster switches to ODO (Odometer)
- press the left button again for more than 2 sec and the service codes should display one at a time in the Odometer field.

Service Codes:
11 Main throttle sensor malfunction
12 Intake air pressure sensor malfunction
13 Intake air temperature sensor malfunction
14 Water temperature sensor malfunction
21 Crankshaft sensor malfunction
24 Speed sensor malfunction
31 Vehicle-down sensor malfunction
32 Subthrottle sensor malfunction
33 Oxygen sensor inactivation
51 Stick coil #1 malfunction
52 Stick coil #2 malfunction
56 Radiator fan relay malfunction
62 Subthrottle valve actuator malfunction
64 Air switching valve malfunction
67 Oxygen sensor heater malfunction
94 Oxygen sensor malfunction
3A Purge valve malfunction

If a service code pops up, check the part and the wiring for open/short then repair. I don't think you can reset the ECU fault codes

If the battery is good, check power and ground to ECU. If no codes are displayed, you have a bad ECU or a mechanical issue.

Sadly, I don't think the Ninja 300 ECU can be hard reset. It stores service codes for warranty purposes.

If you are stuck, I have a service manual in PDF format. PM me with your mail and I will send.
 

Top Bottom