2013 yz 450f runs rough at steady throttle, but fine everwhere else.

[Jonell]

Bought this bike used a couple days ago from local yamaha dealer. Has low hours, but seems to run really rough when i'm not on the gas.  Any ideas would be appreciated!!

 

This is my first post on TT, but no doubt not my last..

 

Thank you for your time.

Edited June 5, 2015 by Jonell

[dirtbeater]

Clean the carb is the first thing that comes to mind. Cheap also.

[03yzf450-kuke]

I dont know much bout the newer bikes but try unplugging the tps and see if it changes anything

[yzdaddy]

Bought this bike used a couple days ago from local yamaha dealer. Has low hours, but seems to run really rough when i'm not on the gas.  Any ideas would be appreciated!!

 

This is my first post on TT, but no doubt not my last..

 

Thank you for your time.

If you just bought it take it back to the dealer. Is it your first efi bike?

[yzdaddy]

Clean the carb is the first thing that comes to mind. Cheap also.

What if it doesn't have a carb?

[03yzf450-kuke]

On the older ones when it runs rough at only a steady throttle is usually a tps problem. I would start by unplugging it and see if that cures it. Dunno if its same as tge carbureted ones though but worth a try

[dirtbeater]

Wow. I am stupid and didnt see the year. My bad. I will go hang my head in shame.

[Jonell]

Just spoke with the mechanic at the dealerership, says he's never heard of that before, told him i'm going to try some fuel injector cleaner in it tommorrow and if that doesnt help then i'll unplug the  tps as you guys suggested and see if that helps.  He also said former owner may have been playing with the map settings. Now I just have to try and locate the tps. 

 

Have to work all day today so it'll have to wait until tommorrow.

[Jonell]

Yes YZDaddy, it is indeed my first efi bike.

[grayracer513]

Unplugging the TPS on a carbed bike disables the 3 dimensional timing map, wherein timing is adjusted both by RPM and throttle position (engine load).  Unplugging the TPS on an EFI system will disable fuel delivery along with that.

 

Get access to either the tech scanner tool at the shop, or a GYT-R Power Tuner, then interrogate the ECU for trouble/fault codes.