surging at full throttle

Hey guys, need some help. Awhile back I posted about how my 2012 YZ 450F would die when you push the "choke" all the way in, and how it surges at high rpm.. Well I brought it to the dealer, and they replaced the tps and said the bike was fixed. Well after a total of an 8 hour round trip, not one of my complaints is fixed. The bike still dies when you push the chock all the way in, and it still has a surge at full throttle. Could they have not set something right and thats why the bike is still surging? If I hold the throttle pinned for 2-3 seconds the bike surges.. My buddys 2010 yz 450 absoulty smokes mine with how it runs right now. Makes it look like a 250f. Any idea? Could this be the beginning of my fuel pump crapping out? Injector? My valves are within spec so I know thats not the problem. I am stumped and pissed at the moment. Any help is appreciated!! 

Fuel filter.

Does not have a spec of dirt in it. That was the first thing I checked. 

Take it back to the dealer, if they diagnosed the issue as being caused by the TPS but the issue is still present they misdiagnosed the problem and need to look at it again. They should not charge you a diag fee a second time around. And do this before you try a bunch of other work again yourself introducing new variables to the equation. 


We all hate having to go to the dealer for help but once you do you kinda need to stick with it, no sense in wasting your money the first time around and then pull your own hair out trying to figure out something you already paid to have diagnosed. 

Edited by grayracer513
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If anyone has anything I should be checking please let me know. I wasted my money at the dealer and will be fighting to get my money back since not one of my issues was addressed. I would love to get this figured out and never step foot in that dealership again. Thanks

Just checking:  You're not talking about the rev limiter, are you?


And you're aware that the cold start knob is also the idle speed adjuster (turn to the left to raise the idle)?

I don't think so. When i ride my buddies 450 I can hold it wide open for as long as I want and it doesn't do anything weird. And that that knob your speaking doesn't changing if you turn in. I have to pull it out and push it in. If its all the way in it wont run unless on the gas and it will run very poor.

Anyone else?

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