Stumble, Hesitation, Dying

2009
Mileage 5300
Build date 11/2008

Parts Removed:
AIS mod
EXUP mod
Air box Flapper mod
Entire Exhaust
Kickstand switch

New:
13/48 + chain
Q4
Mega Bomb
FMF Programmer at 333888
Air Filter
Oil/filter
Batt

I just bought this bike a couple of months ago with 5000 miles on it and all stock. This bike has been boggy and stumbling ever since I've owned it; I've never been able to get it to wheelie yet. I'm 6.2 @ 220lbs and thought as a stock bike I would be able to get the front wheel up in first gear? I’m starting to get a complex…

So I did some upgrades, first was a new chain and 13/48 sprockets. I took it out for a test drive and it was still a dog, and couldn't pop the wheel up. It was still bogging on the low end and really didn’t feel much different than stock.
So I did the next phase of upgrades, which you can see up above. They did make a difference but, it won’t pop the front wheel up and still has no torque down low. I know it's not going to have the low end my YZ250 had but again I thought I would at least be able get the front end up without having to find something to bump it off of? Just so you know riding a wheelie isn’t that important I’m just using that as a base for how bad the low end is. There is defiantly a delay, a slight hesitation when I gas it.

The miles I've put on the bike have all been off road, lately I've been riding a lot of single track woods in temps around upper 70's to mid-80. I run the bike real hard in tight technical stuff and use 1st 2nd and 3rd gears only and, I've noticed the radiator fan running a lot. Now the bike has started to die on me. It's been running really hot while going through the woods and almost got me hurt on one occasion when it died going up a steep embankment off camber. It would always start back up but, it took two to three seconds of holding the starter in to get it too start back up and it would sound like it was flooding out in first gear giving it throttle and then it would die a few feet later (this is with a full tank of fresh fuel). Note it has run hot (fan on all the time in 50 and 60 degree weather) since the beginning when it was stock and continues with the new mods.
It has just started flooding out now that it’s getting warmer outside.

About the only thing I haven't checked or changed is the spark plug, I'm doing that tonight.
The over heat lamp has never came on.
It has never overflowed coolant.
Coolant is fresh and at proper level.
Idle is at 1500 rpm.
Battery is brand new and connections are tight.
Any suggestions?
Too lean?
Fuel pump going?

We have a close setup and im running these numbers and it runs great.


3 4 1 8 6 4.5


No Airbox door/Filter/FMF pipe/AIS/ 12tooth-44tooth rear


Mine ran similar to yours before i started playing with the programmer. Good luck asking questions here... noticed not many people reply

Also may need to bump up the idle just a bit

Get used to not being able to throttle up a wheelie even in first.

I'm running 13/46 on an X and weigh 165lbs. If I'm in the sweet spot I can throttle it up about 50% of the time in first and even then only a foot or without some body english.

As for the other comments on bogging out. Sounds more like running too rich than running lean. With your mods and FMF settings most likely case there is a leaky fuel injector. That is incredibly rare though. Best way to check is to remove the fuel injector from the head. Leave the fuel line and power to it and cycle the key to prime the fuel pump. If there is any visible leakage out of the (engine) end of the injector after cycling the key a dozen times then that's your problem.

Sounds more likely that you just expect more torque than the bike has got to offer and the heat issue is probably from high revs in low gears. Try shifting a gear up from where you have been and see if it improves the heat issue. My fan is only on about 1/2 the time when I'm offroad and almost never when I'm on the road (unless I'm sitting at a traffic light).

Bram wrote:

I just bought this bike a couple of months ago with 5000 miles on it and all stock. This bike has been boggy and stumbling ever since I've owned it;

This doesn't sound good.
Not sure why you'd mod it from stock if it was having issues???? That just adds more complexity to trying to figure out what's wrong.

Was it "boggy and stumbling" when you test drove it?

Fuel pump issues are only supposed to be present on certain 2008 models.

What do you know about the bike's history before you bought it?

chris07r6 wrote:

Good luck asking questions here... noticed not many people reply

Not to sound like a dick, but.............what the hell does that mean????

motokid wrote:

Bram wrote:

I just bought this bike a couple of months ago with 5000 miles on it and all stock. This bike has been boggy and stumbling ever since I've owned it;

This doesn't sound good.
Not sure why you'd mod it from stock if it was having issues???? That just adds more complexity to trying to figure out what's wrong.

Was it "boggy and stumbling" when you test drove it?

Fuel pump issues are only supposed to be present on certain 2008 models.

What do you know about the bike's history before you bought it?

Because I assumed it was how they ran stock and that I could fix it with mods.

Yes it was boggy to me when I test drove it.

Bikes history, it was left completely stock and only rode as a commuter on hard top.

I think my biggest problem is the fact that I've been running two stroke dirt bikes since 1976 and this is my first fuel injected four stroke.

You should look at the threads here on FMF fuel programmer settings. Read them.

Also, try to find somebody else near where you live that has a wr250x/r.

Check out supermotojunkie.com too for people who might live near you.

It would be a huge help to have somebody else help you in person.

Where are you exactly?

I would start by looking at your programmer settings.

And yes - a 250cc single cylinder 4 stroke will feel HUGELY different than any 2 stroke race/dirt bike.

And yes - there really is no power wheelieing on these bikes. Got to use clutch technique.

motokid wrote:

chris07r6 wrote:

Good luck asking questions here... noticed not many people reply

Not to sound like a dick, but.............what the hell does that mean????

When people ask questions here they usually go over looked and unanswered.

motokid wrote:

chris07r6 wrote:

Good luck asking questions here... noticed not many people reply

Not to sound like a dick, but.............what the hell does that mean????

even bad questions get replies here

motokid wrote:

And yes - there really is no power wheelieing on these bikes. Got to use clutch technique.

yeah i would agree BUT I can say my bike has surprised me some times .. i think it would depend on gearing .. body position .. and if your not afraid of hitting the rev limit

cryptomundo wrote:

motokid wrote:

And yes - there really is no power wheelieing on these bikes. Got to use clutch technique.

yeah i would agree BUT I can say my bike has surprised me some times .. i think it would depend on gearing .. body position .. and if your not afraid of hitting the rev limit

What he said...

That aside, unless you're used to riding a modern crotch rocket it's hard to imagine anyone thinking a properly running WR was "bogging". The throttle response on mine has always been quite great.

Maybe the bogging is from gear choice or clutch handling? It's hard to tell.

OP: Can you upload a video of you riding around in a parking lot (with audio)? That might help with a remote diagnosis.

chris07r6 wrote:

motokid wrote:

chris07r6 wrote:

Good luck asking questions here... noticed not many people reply

Not to sound like a dick, but.............what the hell does that mean????

When people ask questions here they usually go over looked and unanswered.

That's total bullshit.

Arkmage wrote:

That aside, unless you're used to riding a modern crotch rocket it's hard to imagine anyone thinking a properly running WR was "bogging". The throttle response on mine has always been quite great.

Maybe the bogging is from gear choice or clutch handling? It's hard to tell.

OP: Can you upload a video of you riding around in a parking lot (with audio)? That might help with a remote diagnosis.

Could the bogging be him hitting rev limiter?

A two stroke won't have that feel.

motokid wrote:

chris07r6 wrote:

motokid wrote:

chris07r6 wrote:

Good luck asking questions here... noticed not many people reply

Not to sound like a dick, but.............what the hell does that mean????

When people ask questions here they usually go over looked and unanswered.

That's total bullshit.

At least everyone is friendly...

chris07r6 wrote:

motokid wrote:

chris07r6 wrote:

motokid wrote:

chris07r6 wrote:

Good luck asking questions here... noticed not many people reply

Not to sound like a dick, but.............what the hell does that mean????

When people ask questions here they usually go over looked and unanswered.

That's total bullshit.

At least everyone is friendly...

This forum is the BEST resource on the internet for anything and everything and all things wr250r/x.

motokid wrote:

chris07r6 wrote:

motokid wrote:

chris07r6 wrote:

motokid wrote:

chris07r6 wrote:

Good luck asking questions here... noticed not many people reply

Not to sound like a dick, but.............what the hell does that mean????

When people ask questions here they usually go over looked and unanswered.

That's total bullshit.

At least everyone is friendly...

This forum is the BEST resource on the internet for anything and everything and all things wr250r/x.

You need to take your calm down meds ASAP

motokid wrote:

Arkmage wrote:

That aside, unless you're used to riding a modern crotch rocket it's hard to imagine anyone thinking a properly running WR was "bogging". The throttle response on mine has always been quite great.

Maybe the bogging is from gear choice or clutch handling? It's hard to tell.

OP: Can you upload a video of you riding around in a parking lot (with audio)? That might help with a remote diagnosis.

Could the bogging be him hitting rev limiter?

A two stroke won't have that feel.

Are you serious? I doubt hes mistaking the rev limiter for a stumble

motokid wrote:

Could the bogging be him hitting rev limiter?

A two stroke won't have that feel.

I read that as he's not happy with the throttle response. When he slams open the throttle he get's a minor delay (which would indicate too lean typically) and sometimes it goes so far as wanting to stutter or stall.

Arkmage wrote:

motokid wrote:

Could the bogging be him hitting rev limiter?

A two stroke won't have that feel.

I read that as he's not happy with the throttle response. When he slams open the throttle he get's a minor delay (which would indicate too lean typically) and sometimes it goes so far as wanting to stutter or stall.

I honestly think after you try some different setting on your FMF programmer ur going to be happy

chris07r6 wrote:

motokid wrote:

Arkmage wrote:

That aside, unless you're used to riding a modern crotch rocket it's hard to imagine anyone thinking a properly running WR was "bogging". The throttle response on mine has always been quite great.

Maybe the bogging is from gear choice or clutch handling? It's hard to tell.

OP: Can you upload a video of you riding around in a parking lot (with audio)? That might help with a remote diagnosis.

Could the bogging be him hitting rev limiter?

A two stroke won't have that feel.

Are you serious? I doubt hes mistaking the rev limiter for a stumble

Your correct chris07r6 and thanks.

chris07r6 wrote:

Arkmage wrote:

motokid wrote:

Could the bogging be him hitting rev limiter?

A two stroke won't have that feel.

I read that as he's not happy with the throttle response. When he slams open the throttle he get's a minor delay (which would indicate too lean typically) and sometimes it goes so far as wanting to stutter or stall.

I honestly think after you try some different setting on your FMF programmer ur going to be happy

Correct again! I went out for an hour ride and tried different settings on the FMF programmer. The bike never acted up once. I'm going to try some more tomorrow.

The motok is quick to give shit...its proly cause he's quick...
I'm pretty sure you were lookin for a quick answer, when the topic has been discussed from several angles already...whether relevant or not.
Regardless, good luck with your programming, hope it's not more than that.

Motokid is blunt. I like it.

Thought I might put my $0.02 in here. 1st/2nd, throttle on lean back - wheelie further then I am comfortable with (at this point anyway). 3rd not so much but it doesn't take much help and the front comes up fast. Granted I am only 135/5'6 so that is a huge bonus. I have a power to weight advantage over most.

As for the stumble I am currently trying to fix this as well. Think I am rich which I thought wouldn't be an issue as I have done the airbox mod as well as added six uni vents to the airbox. I have as much air going in as I can without removing the door which isn't an option as I ride in dust mud and crud. FMF PP settings are next. Just need to free up some time to do it.

Bram wrote:

I went out for an hour ride and tried different settings on the FMF programmer. The bike never acted up once. I'm going to try some more tomorrow.

If your entire issue was something as simple as FmF settings then happy day for you. Doesn't get any easier than that.
However, that doesn't really explain why you were having issues when the bike was stock, but that's neither here-nor-there if everything is peachy now.

I'll skip everything else, but I do want to call attention to the fact that in roughly six hours from your original post, you got what looks to be a total solution to your problem.
Further proof that this forum is in fact a highly valuable resource and that any snarky comments about it have little to no truth about them what-so-ever.

Hope your issues are completely sorted out. Please post the FmF programmer numbers you settle on once you feel the problems have all been taken care of.