[CrfrallyBCboy]

Hi everyone. Im new to motorcycling and amateur at dirtbiking. Bought a pretty used 2017 rally. I got my license and on my first actual street ride it started revving on its own. High and then low out of no where. Im also getting backfire when i try to pull the throttle. I opened the casing that holds the throttle cable and it wasnt stuck or snapped or anything. Im so lost and dont know what to do. Its really turning me off on being on a bike. Especially having that happen on the road. Anyways this is the video. I hope someone can help. Thanks for the read and stay safe everyone! (I have also checked for leaks and ive already checked all fluids everything seems good.)

[JimDirt]

Welcome to the site !!

No link is showing up , so either you forgot to post it or something ......

As far as your description , it sounds to me like the bike has something going on with the fuel pump surging or something of that nature where it is causing a lean condition , then rich , maybe a filter that is partially clogged , or even a injector that is going bad , possibly even the ECU is acting up ...... if the throttle works freely and "snaps back" when you twist it then let go , then it has to be something in the throttle body , or a electrical issue , as any cable binding would be noticed by the throttle sticking or hanging up physically , where you would have to manually twist the throttle back to stop and the issue goes away , I have not heard of this issue with them before , but that does not mean there is not a issue with yours .....

[CrfrallyBCboy]

Sorry this is the youtube link I cant upload on here

[CrfrallyBCboy]

Welcome to the site !!

No link is showing up , so either you forgot to post it or something ......

As far as your description , it sounds to me like the bike has something going on with the fuel pump surging or something of that nature where it is causing a lean condition , then rich , maybe a filter that is partially clogged , or even a injector that is going bad , possibly even the ECU is acting up ...... if the throttle works freely and "snaps back" when you twist it then let go , then it has to be something in the throttle body , or a electrical issue , as any cable binding would be noticed by the throttle sticking or hanging up physically , where you would have to manually twist the throttle back to stop and the issue goes away , I have not heard of this issue with them before , but that does not mean there is not a issue with yours .....

Sorry that is the link.

[JimDirt]

That definitely sounds like it is fuel surging , maybe Leardriver will chime in soon , if anyone can figure this out , it is him if it is fuel related ...... I have never heard one do this before , so this issue is new to me .... , it reminds me back in the early 80's when I raced Drag Boats , I had a Blown Gas Flat Bottom and Blown Alcohol Hydro , and they would surge like that we used to call it Blower Surging , , only time I have ever heard anything sound that way ....

Pretty much like this Blown Fuel Hydro

[CrfrallyBCboy]

That definitely sounds like it is fuel surging , maybe Leardriver will chime in soon , if anyone can figure this out , it is him if it is fuel related ...... I have never heard one do this before , so this issue is new to me .... , it reminds me back in the early 80's when I raced Drag Boats , I had a Blown Gas Flat Bottom and Blown Alcohol Hydro , and they would surge like that we used to call it Blower Surging , , only time I have ever heard anything sound that way ....

Pretty much like this Blown Fuel Hydro

Thanks for giving me some clues man. Im surprised this would be happening to a fuel injected bike. If fuel is surging does that mean il need new injectors? Also forgot to add the fuel is a few months old. I have to drain it. I might give that a try after work.

[Back2-2]

My suspicion is you have a inlet or exhaust sensor that is failed or failing. Similar to a MFS -Mass flow sensor on your car.

You might try disconnecting the battery and see if you can "reset" the ECU. If that fixes it, that probably is not going to fix it for any length of time but it will give you some info. to continue trouble shooting.

Don't give up on riding bikes just because your bike as something that needs to be corrected. Bikes are a joy and pleasure to have and ride.

[CrfrallyBCboy]

My suspicion is you have a inlet or exhaust sensor that is failed or failing. Similar to a MFS -Mass flow sensor on your car.

You might try disconnecting the battery and see if you can "reset" the ECU. If that fixes it, that probably is not going to fix it for any length of time but it will give you some info. to continue trouble shooting.

Don't give up on riding bikes just because your bike as something that needs to be corrected. Bikes are a joy and pleasure to have and ride.

Im going to give it a try when i get home. Thank you guys so much for the input really helps. IL KEEP YOU GUYS POSTED!!!

[CrfrallyBCboy]

My suspicion is you have a inlet or exhaust sensor that is failed or failing. Similar to a MFS -Mass flow sensor on your car.

You might try disconnecting the battery and see if you can "reset" the ECU. If that fixes it, that probably is not going to fix it for any length of time but it will give you some info. to continue trouble shooting.

Don't give up on riding bikes just because your bike as something that needs to be corrected. Bikes are a joy and pleasure to have and ride.

So i disconnected the battery. Left it for an hour put it back to the same problem. Ive also found what i believe is the o2 sensor on the exhaust pipe. Its pretty hard to get too. Do i need to take it apart to find the problem?

[Aussiecrf230]

I would have thought an O2 sensor or O2 sensor wiring fault would throw a code at you identifying a problem. Normally would fail as being rich mixture and high fuel use.

I assume you don't have a air leak that is opening and closing with engine movement? Can be hard to find without a lot of pushing or pulling and making sure clamps are tight.

What does it do with a fast idle?

[CrfrallyBCboy]

I would have thought an O2 sensor or O2 sensor wiring fault would throw a code at you identifying a problem. Normally would fail as being rich mixture and high fuel use.

I assume you don't have a air leak that is opening and closing with engine movement? Can be hard to find without a lot of pushing or pulling and making sure clamps are tight.

What does it do with a fast idle?

I cant find an air leak. Its idleing on its own. When i pull the throttle it either does nothing or revs super high or causes backfire.

[Back2-2]

Maybe the TPS - throttle position sensor is bad or out of adjustment?

[CrfrallyBCboy]

Maybe the TPS - throttle position sensor is bad or out of adjustment?

Unfortunately after ripping the bike apart I have come to no solution. I pulled the o2 sensor plug i believe it is and looked at it. Seems clean and looks like its in functioning order (i hope). I unplugged the negative terminal pulled the o2 and left it for an hour. Put it back and now I have a code but I dont have a reader. I think its time to take it to a mechanic.. i have a feeling they will be ripping my bumm with $$$$$$$$$. If thats the case as sad as it is i will end up leaving my motorcycling days behind me. Really not happy with this. Thanks for all the input I appreciate you all and this forum page. I will put out an update eventually when i find the issue..

[Discernment]

Hey, I just started to have this problem wuth my bike as well, 2017 rally. Hoping to see if you or the mechanics had come to a solution or if anyone has any ideas how to solve it, thanks!

[Discernment]

So in my case, the subframe bolts had vibrated completly off, and the entire subframe was shifting backwards, causing the throttle body to shift away from the engine. Weird problem but easy fix, just had to put the subframe back together, realign the throttle body, and do a few oil changes to get all the dirt out haha