WR 250x modding question spefically power commander etc

If i get a fmf powercommander 4 and do the airbox mod and 12/43 sprocket, and i get a dynojet power commander do i need to go to a dyno test and get it tuned or can i get it done myself from home without possible damaging something?

And if i dont do the airbox mod and just get a fmf powercommander 4 and 12/43 sprocket do i still need a power commander?

Thanks in advance!

I can't quite follow you: you're asking whether you need two power commanders, an FMF and a Dynojet?

BTW, sprocket sizes do not affect fueling, so they're irrelevant to this discussion.

johnkol wrote:

I can't quite follow you: you're asking whether you need two power commanders, an FMF and a Dynojet?

BTW, sprocket sizes do not affect fueling, so they're irrelevant to this discussion.

I just saw my mistake did not mean powercommander but fmf powercore 4. So an exhaust slip on not another powercommader my bad.

EddieL wrote:

I just saw my mistake did not mean powercommander but fmf powercore 4.

That makes more sense.

If you get a Powercore and don't open the airbox, then you won't need a power commander, but in that case what is the benefit of an aftermarket exhaust? Just a small reduction in weight?

If you get a Powercore with a power commander and modify the airbox, then the best way to set up the Dynojet is to take it a shop with a dyno. Alternatively you can get the Dynojet Autotune and go through the tuning process yourself. Or you can simply tune it manually by feel; it would take an extreme setting to potentially damage something, and you're going to have other indications that things are not working right before any damage occurs.

johnkol wrote:

EddieL wrote:

I just saw my mistake did not mean powercommander but fmf powercore 4.

That makes more sense.

If you get a Powercore and don't open the airbox, then you won't need a power commander, but in that case what is the benefit of an aftermarket exhaust? Just a small reduction in weight?

If you get a Powercore with a power commander and modify the airbox, then the best way to set up the Dynojet is to take it a shop with a dyno. Alternatively you can get the Dynojet Autotune and go through the tuning process yourself. Or you can simply tune it manually by feel; it would take an extreme setting to potentially damage something, and you're going to have other indications that things are not working right before any damage occurs.

I see, it also is a euro spec bike so it has an o2 sensor i guess i would just disconnect that and leave it be? And as far as i know you cant use that o2 sensor to setup an autotune with dynojet right?

The Autotune module needs an O2 sensor, and the kit contains an O2 bung for that exact purpose; if you already have one then you're in luck because you can simply connect that to the autotune module.