Stalling when hitting the face of a large whoop or g out?

[Bajajoe]

Yo!

So my last few dez races I have had a reoccuring problem.

As I come to a huge whoop or ditch, shut of the throttle because I cant just power through it, and go to whack the throttle like a seat kicker jump...

The bike shuts off!!! Then, of course, instantly comes back on.

So I get this first action of seeing my front fender and then I get my arms stretched.

I race in some big whoops so maybe I need a diff approach but I thought I would ask.

Does anyone else have this? My dealer said to get a aftermarket floatbowl?

I have a;

2007 CRF450x

pink wire cut

04 R cam

CMH Full Exhaust

Airbox cut

no screen

No oring mod needed right???

Jetting is pumped up a bit per talk on here; I will pull the carb today to make sure I have the exact numbers

I will also check the float level to see if it is out

Any thoughts?

[kanyonkritter]

I was thinking float level...I had a pig of a DR at one time that would do that all the time, after messing with the float level I got it cleared out.....do you experience bog at any other time or is it just the G-outs and big hits?

[Bajajoe]

The bike run perfect all the other times. even when hitting rock faces going up tight canyons and such.

And of course up top rpm when I smoke those halloween bikers.

Check the float. Thanks. It has been a while since I did that.

[dakynz]

sounds like the case of Bog! Have you adjusted your leak jet??

I had a pretty bad wreck trying to jump a ravine when the bike stalled on me and front tire went in the ravine. Did some searching on here and ended up putting the Merge racing spring on and replacing the stock 70 leak jet with a solid screw. Absolutely no bog now. If I had to do it over again I may have gone with the 55 leak jet as recommened but posted up on the jetting forum and Eddie recommended blocking the leak completely.

[whyfly]

Does your bike have a kick stand safety switch? The one on my DR-Z about killed me cause it was doing the same thing. Ran great, hit some harsh bumps, and cut out for a split second, then run great again.

[dakynz]

no the x does not have the safety switch that is on the DRZ

[kanyonkritter]

Does your bike have a kick stand safety switch? The one on my DR-Z about killed me cause it was doing the same thing. Ran great, hit some harsh bumps, and cut out for a split second, then run great again.

I killed that thing on my DR first time it happened

[450XJimDirt]

If it only does it when you completely let off then grab a handful then its the CRF bog , you need to dial in your jetting better , using a Quickshot will help alot , mine always did it in 3rd coming out of a hard corner , it would fall flat on its face and if i didn't let off the throttle again it would just come to a stop , if i backed off it would re-light and then go(sounds like what yours is doing) , its definately carb settings , sounds like your jetting is too lean by means of either Acelerator pump timing or leak jet or both

and you dont have to do the O-Ring mod , just re-adjust the gap to the guage that comes with the Quickshot cover

[FORMA MOTO]

- Merge racing Accel pump linakage spring

- 45 leak jet

I also added the R&D powerbowl and APump cover with adj leak jet.

Major improvement.

[cubera]

I had the same problem, Joe. Turns out the MJ was ovaled and the needle tip was worn out and I think it would load up too much when rolling off the gas too fast then getting back on it. I could be totally insane in my thinking (not unusual) but a new needle and MJ fixed it.

[WWEVERETT]

Accelerator pump dumping to much fuel and flooding it.

[thumpyz]

sounds like an Ap issue to me. whacking the throttle open like that cuts vacuum enough to kill the engine, thats what the ap is for, and it sounds like your needs to be tuned. I went with a 55 leak, and put the small o-ring from the jd jet kit on my ap linkage, and now i dont have any bog what so ever.

[Bajajoe]

WOW!!

All I can say is Thumpertalk rocks.

I really appreciate all the replys.

Let me get the carb out and check it out.

This leak jet thing is new to me. Smaller leak jet means more fuel is in the float bowl. Larger leak jet means less. Now where did I put my flux capacitor?

Ovaled main jet... I have seen this on the KX500s. They would eat needles and main jets. A new set each race season solves the problem. But this would not affect mixture right off the bottom.?

Ap problems. Too much or too little. In the past a bog off idle with WOT is not enough fuel, but....

Aftermarket AP cover and float bowl w adj leak jet. maybe this is what i need...

Thanks again so much. Look for a post this afternoon with pics.

[kanyonkritter]

WOW!!

All I can say is Thumpertalk rocks.

I really appreciate all the replys.

Let me get the carb out and check it out.

This leak jet thing is new to me. Smaller leak jet means more fuel is in the float bowl. Larger leak jet means less. Now where did I put my flux capacitor?

Ovaled main jet... I have seen this on the KX500s. They would eat needles and main jets. A new set each race season solves the problem. But this would not affect mixture right off the bottom.?

Ap problems. Too much or too little. In the past a bog off idle with WOT is not enough fuel, but....

Aftermarket AP cover and float bowl w adj leak jet. maybe this is what i need...

Thanks again so much. Look for a post this afternoon with pics.

Go with a #55 leak jet, o-ing mod the acc. pump, check acc. pump timing and you should be bog free:thumbsup: