Uncorked the bike, now bike dies

If you do it is small increments and keep track of how much you turned it you should be okay.

Awesome thanks!!!

No, The catch tank is suppose to be filled to the fill line.

*Try and get the dealership to load the FMF map with the GYTR Tuner so you'll be good to go.

I asked the same question about the catch tank when I picked up my bike (2015 WR450F) and got the same answer.  Just checked my service manual (page 3-17) and there is no mention of coolant in the catch tank.  The SM says to check the coolant on a cold engine by removing the radiator cap. 

I read the FAQs and the performance mods section for the bike but cannot find what I was searching for.  Is there a link or a thread that describes the range of options for performance upgrades for the WR450F?  Does Yamaha have a tuning guide for the bike?  I see they sell lots of parts but have not found a refernce to a tuners manual.  I have not ridden a serious dirt bike in 38 years so don't plan on any immediate changes but I would like to understand the options.


If I understand correctly, I need the competition ECU to get the YZ throttle stop screw (unless I can find the part number somewhere) and to use the GYTR tuner to change maps.  The competition ECU does not provide any performance change; it just allows the use of the tuner.  Is that correct?


Some other questions:

- If I uncork the bike, is it possible to go back to stock exhaust setup by putting the parts back in (knowing that I will have to re-adjust CO)? 

- Will I get performance improvements if I change maps without uncorking the bike?  Am thinking that I should add performance in small increments as my skills improve/ return.

You have to un-cork,  and re-ecu with a re-map if you want it to run at the right temp, and not stall or overheat.

This is the way it is.


Re-mapping is not a 'performance' upgrade past the input/output flow of the motor. It's just how you correct poor A/F ratios, just like jetting.


In otherwords, you will get the A/F ratio correct, and if you vastly upgrade the head, exahust, or intake, you re-map to correct your now incorrect A/F levels.

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