Is flapper valve/AIS removal required?

Hey guys,

Just ordered fmf powercore 4 slip on and fmf programmer, also throwing a UNI filter in.

My bike is still under warranty I was wonder if it's really necessary to do those 2 mods?

Thanks.

No....you don't HAVE to.....

I've read the AIS with aftermarket exhaust is bad for the engine?

The AIS is post engine.

You might have some issues with back-firing on deceleration.

If it's an issue...remove it.

If you don't have back-firing, leave it if you want.

It's just extra weight once you remove stock exhaust.

motokid wrote:

You might have some issues with back-firing on deceleration.

A little "popping" never hurt no one! I actually like a good backfire every now and again.

No necessary.. but they are easy to do so why not.

About the only change youll get from AIS removal is maybe your exhaust packing will last longer without the fireballs and backfires.
But mine is kind of fun at night lol.

https://www.youtube.com/watch?v=kbOBUGKoT4o

I totally gutted the flapper and cut a hole about 2 1/2 by 2 1/2 inches in the airbox right above the airfilter looking to get as much hp as possible.
You will need to richen up the efi to get the most out of that mod tho.
You could leave the airbox completly stock if you wanted, you just miss out on a couple of hp on the top end, opening up the airbox adds just as much hp as adding a pipe. Its a must do mod if you have a pipe, theres no point in having a open high flowing pipe with a choked up airbox IMO.

The AIS is just dead weight after you remove the stock pipe, the cat in the stock pipe needs it aftermarket pipes dont.
I ran with the AIS still working with a Q4 for a couple of hundred kms then removed it, I cant tell any difference at all.
If you feel like removing it, toss it, if it doesnt bother you leave it lol.

You will need to deal with the exup cables and servo too.
One easy way to deal wih the exup without buying anything is to pull the cables out of the servo motor and leave the servo hooked up, thats what I did.

Can someone link me a guide to doing the exup/servo mods so I don't get an engine code?

shep546 wrote:

Can someone link me a guide to doing the exup/servo mods so I don't get an engine code?

I bought one of these and plugged it into where the servo use to be connected. There are some cheaper ways to do this but I thought this was the cleanest solution.

http://shop.12oclocklabs.com/index.php?route=product/product&product_id=94

shep546 wrote:

Can someone link me a guide to doing the exup/servo mods so I don't get an engine code?

https://wr250rforum.forumotion.com/t627-cheapest-diy-servo-bypass <-- click it

Thanks guys

I also just ordered a PC4. I am planning on doing the aid and air box mod. Will it be fine to do all of this without having programer? Thanks

haygood wrote:

I also just ordered a PC4. I am planning on doing the aid and air box mod. Will it be fine to do all of this without having programer? Thanks

I did some research and went with the programmer...

it turns out doing all those mods and only using the stock fuel mapping is not a good idea

shep546 wrote:

haygood wrote:

I also just ordered a PC4. I am planning on doing the aid and air box mod. Will it be fine to do all of this without having programer? Thanks

I did some research and went with the programmer...

it turns out doing all those mods and only using the stock fuel mapping is not a good idea

That is an absolute fact. A local tuner tells a lot of great stories about guys who replace everything on their new bike (the WR series are typical victims along with Hardleys and R6/R1s) and produce bikes with about 90% of stock power and a tiny powerband. If you change anything in the intake or exhaust, you're playing with forces beyond your comprehension unless you have access to a dyno and remap the controller. It's fairly complex and often expensive.

One of the old guys I ride with bought a WRR with all of the usual "power farkels" installed: trick and noisy pipe, massacred airbox, flapper and servo removed, etc. The upside was the bike was dirt cheap because of all the improvements (a 2008 with 800 miles = $1800). The downside was on pavement or in the gravel we produced a dead heat in a bunch of standing stop and starting at 30mph drag races and I weigh 50 pounds more than him. He ran out of steam about 10mph below where my bike stops, too. All that noise, a voided warranty, and . . . less power.

Does the old guy you ride with have any type of programmer?
The tuner you were talking to sounds like a good salesmans too lol.
You dont need to put your bike on a dyno, lots of others have, run their settings you will be pretty close lol.
With the fmf programmer, run fmfs settings they're very good, I tried richer dyno tuned settings I found on here and had stumbuling isues untill I went to fmfs settings.