04' 450 bog/hesitation on hard landings?

[BK14MX]

Went to a track this weekend with some pretty big jumps, not just long, but flippin high too. I was having trouble when I landed from the biggest one, my bike was bogging/hesitating almost everytime I jumped it. Its a big jump with ALOT of air time, I havent had a chance to take the carb apart yet, but Im guessing all things being clean in it, that maybe the float level is too low???

Anyone else ever run into this?? ?

[NE14MX]

I've experienced the same thing. At first I thought I was somehow hitting the kill switch when landing. I think your right about adjusting the float level, but I don't know if it's too high or too low. I used to get this on my YZ250 until I double vented the carb but on the CRF450 the carb's allready vented that way. Hopefully, someone can help.

[todd92]

Try adjusting the fuel screw richer (out) first.

[BK14MX]

We are planning on riding that track again this coming weekend, I will try the fuel screw. I clean the carb today, no junk inside. Thanks.

[viking24]

Hey BK14MX has this been a cronic problem or has it just started? Do you have an adjustable fuell screw on it?

I have experienced the same deal.

[BC179]

BK14, hold it on the rev-limiter in the air that way it won't bog ?

[berkeman]

Went to a track this weekend with some pretty big jumps, not just long, but flippin high too. I was having trouble when I landed from the biggest one, my bike was bogging/hesitating almost everytime I jumped it. Its a big jump with ALOT of air time, I havent had a chance to take the carb apart yet, but Im guessing all things being clean in it, that maybe the float level is too low???

Anyone else ever run into this?? ?

I remembered a couple threads about this in the CRF450 forum, and did a quick search (float landing). Here are a couple of the hits:

https://www.thumpertalk.com/forum/showthread.php?t=137396&highlight=landing+float (fixed -- dirt in the carb jets)

https://www.thumpertalk.com/forum/showthread.php?t=65442&highlight=landing+float (no fix listed, but some ideas)

https://www.thumpertalk.com/forum/showthread.php?t=44667&highlight=landing+float (no fix listed)

[viking24]

My '04 CRF450 gives me that same annoying hesitation when landing hard or jumping through rhythm sections. I have tried multiple fuel screw and jet settings with no fix. Here are 2 things that I have come across that are pretty interesting though.

1. Aftermarket fuel screws seem to vibrate themselves out. Perhaps the added size/weight allows this to happen. It was suggested to dab some silicon around the fuel screws hole to keep them in place.

2. Also heard that Boyesen was working on an Accelerator Pump cover that is directed at solving these bogging problems. Something about air in the accel pump causing fuel pickup problems when you snap the throttle. Sounds promising