Do I need to Re-Map WR250R after changing pipes?

I have a 2012 WR250R Dual-Sport. Here is my question, I jus put on  FMF Q4 and a FMF Cherry bomb header.


The bike is FUEL INJECTED, will the bike adjust to the changes I made without me doing damage to the motor.


Someone told me it will run TOO LEAN and hurt the valves if I don't re-map it to get more fuel to it???


I was thinking the fuel injection would adjust to the bikes fuel needs automatically.


If you have any thoughts on this Please hit me back.



I do not think the bike will automatically adjust the fueling to the degree you'd want, if at all.

For that, I believe the bike's electronics would need some kind of "sniffer" sensor in the exhaust pipe to take measurements of what it's doing and make changes accordingly.


I haven't read of anybody actually melting their WR-250R down by installing aftermarket exhaust pipes and mufflers without adding a fuel programmer, but I can tell you from personal experience the bike will not have throttle response that is as good as with one added.

north american wr250r/x did not have o2 sensor on them from factory when they where 1st imported. your 2012 might and then it would adjust to the different pipe according to the o2 sensors readings over time.  i would check and see if it has an o2 sensor on it 1st.

The FI in the WR250R only changes its fueling depending on air pressure and air temperature. It has no way of knowing if the intake or exhaust is opened up.


get a programmer

I have a question. What if you only change the pipe and not the header?


I have a question. What if you only change the pipe and not the header?



Same result, really:

The bike will run, and lots of riders report to be perfectly happy with this (I feel the savings of $$ has much to do with it), but throttle response is noticeably better with the fuel programmer.

Yes. FMF makes one, but if you're going that far, do the whole PC route. It will be lean with the new exhaust, so you need to attend to it asap. Especially now the weather is cooler, it needs still more fuel for the increased O2 in the denser cool air. There are canned maps you can get with the Power Commander that are very close, but having it done on a dyno will be ideal. The stock FI has no ability to auto correct. It can't tell you did the mods, as it has no closed loop capability (O2 sensor).

Thanks, I was looking at a used model at a dealership and noticed the pipe had been changed and this made me realize I had not considered some factors like this when evaluating used bikes.

Edited by OBJMS33

Thanks, I was looking at a used model at a dealership and noticed the pipe had been changed and this made me realize I had not considered some factors like this when evaluating used bikes.

If the price is reasonable, why not? Many people want these mods, and you're 2/3 the way there.  


If it were me, and the price were what I expected to pay, the bike in suitable shape, I'd get it. If the stock parts came with the bike, I'd definitely get it. That isn't a deal breaker, but always a plus.  This time of year is certainly the time to buy: more leverage on your part to get the dealer to deal. If you're questioning what the condition is other than visually, get the dealer to give you a xxx mile, xxx month warranty as well. 


What other mods? New off the showroom floor, and depending upon how you want to use it, various modifications are considered very valuable. Bash plate, radiator board, YamaLink, just about any tire other than the stock TW301/302s (to name a few) are all standard things people do. So if they are already there, you're ahead by about 500-700 plus the cost of the exhaust, which is another 500-700. 


The other option is to have the dealer install the PC as part of the deal, it will roll into the price.

Dealer wanted 4500. Which probably did not include tax and lic. Found another one on craigslist for 4200. Re-geared, FMF pipe and FMF programmer, new chain and sprockets. Dont know why he replaced chain when it has only 5k on the engine. I have a KLR and a vstrom. Finally am out of debt and got a savings together. Would like to have a trail bike to play with but dont want to torpedo my budget. Was thinking of getting a off-road WR but dont want

to deal with changing oil and tuning every three rides. And depending on my needs the KLR my go somtime. Just something Im tossing around if the right deal comes up. And it is super fun to shop!!!

I use my WRR for dirt, and just ride it on the road to get to the dirt. The chain has a tough life with a primary dirt diet. So 5k isn't that nuts.

$4200-4500 isn't too stiff if in nice shape. If it has aftermarket exhaust, I'd expect to have the stock stuff as part of the deal. If it ever comes to be enforced, you'll have to find a stock exhaust to pass emissions. If you read up, the Feds are considering adopting the CARB standards that require the the catalyst to be intact. Just keep that in mind. Often, the more stock it is, the better.

If you do get one, it needs lower gearing for off road use. I kept the standard front sprocket, changed to a 47T Sunstar rear, added one link and a pair of rivet masters. The stock rubber is worthless for anything but 70 degree dry paved roads.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now