450r hybrid bog

[1fst400]

My R motor in my 400 frame bogs every time I land off a jump.

Not just rough landings, seems the smoother I land the more I notice that it has nothing when I land off jumps. When I get squirlie in the air when I land and get bounced around Im shure it still does it but my mind is on other things so I dont notice it as much.

My thot is somthign in the jetting??? doesent do it any other time. on occasion in 5th gear on flat just as I reach max rpm it sputers a cuple times.

[†2005 400ex†]

yea, something with the jetting would be my first guess...by the way, how do you like your hybrid?

[GPracer2500]

Prolly the first thing I'd look into is the float height. Be sure it's at or very close to spec.

[mattonln]

yeah, its definetely a carb problem, probably not jetting, check your float like he said. even if you have to go higher than spec, the geometry of that frame is different and might put the carb in a more offset position than it was designed for... just an idea...

[1fst400]

what is the speck on the float bowl? and how do you measure it? to change it you just bend the little tabs corect?


The carb sits same as it would in a 450r frame. cant be that, guys do backflips and they arent worying about a bog when they go to land.



Ya, I love the hybrid. It pushes quite a bit going into corners, and it flyes a little wierd. But my front tires are bald and I got used to jumping it.

[xtullyx16]

Do u have any pics of it?? and did u fix the problem?

[xtullyx16]

It must be ur spark plug because its getting enough spark when u use ur thottle and the a-arms are prolly robbing all the power maybe u need to put a pink powerband on that thing?!:blah: :macho

[YZ120]

make sure that the float bowl isnt touching anything.
2smokes will bow from this.

also is there a bog when you crack the throttle from idle?
you could be lean on the pilot jet-air screw.

[underpowered]

Originally posted by YZ120
make sure that the float bowl isnt touching anything.
2smokes will bow from this.

also is there a bog when you crack the throttle from idle?
you could be lean on the pilot jet-air screw.

Huh? a 450r is not a 2smoke there buddy.

i would check the float level first.

[YZ120]

Originally posted by underpowered
Huh? a 450r is not a 2smoke there buddy.

i would check the float level first.

same thing can happen on a 4stroke
you are correct on the float though.def. try it first.

just trying to help!!

[rmz250]

This is known as the common FCR bog. It has to deal with the accelerator pump. Try the boyseen quickshot.

[1fst400]

it doesent bog a bit when I accelerate.


I swear some of you guys are talking from your but hole.


I dont know what to check for whith the float, its perfectly cleen in there. Not a spec of nuthin. What do I set the float to.

[rmz250]

Originally posted by 1fst400
it doesent bog a bit when I accelerate.


I swear some of you guys are talking from your but hole.


I dont know what to check for whith the float, its perfectly cleen in there. Not a spec of nuthin. What do I set the float to.

Are you retarded? when youland your back on the throttle resulting in the hesiatation.

[1fst400]

I am not retarded.



I'm fumiliar with the bog you are refering to. I had a fcr carb on my 400ex motor, that thing would bogg on acceleration all the time. But not when I landed.


If it was the bog that you are refering to it would do it on normal acceleration also. But I can punch this thing from an idle and it wont bog a bit.


Im going to take the carb apart tommarow and look things over.

ANY TIPS AS TO WHAT TO SET THE FLOAT BOWL TO? I already looked it over and saw that everything moves freeley in there. nothing looks ab normal.

btw rmz250 I wasnet refering to you, I was more talking about the guy that told me I need a new powerband.

[GPracer2500]

I'm not sure what the float height spec should be. I'd use (or at least start with) the stock 450r spec. A service manual will have that info. If you have a freindly service department, then you could call and ask for the spec.

But even if you don't have the spec you can try just lowering the fuel level in the float bowl from whatever it is now. Maybe try 2-3mm at a time. If a high float level is the issue than you should be able to clear it up.

BTW, which carb is this? The MX varient of the FCR has a float bowl with higher capacity and a fuel baffle. These features are there to reduce what you're experiencing when jumping. Not sure if the 06' 450r FCR is an MX or not...

BTW, the float height is measured from the bottom of the carb body to the bottom of the float. This is measured when the float is postioned just so it fully closes the float needle valve. Don't just press the float all the way up/in--that will just compress the spring in the needle valve. And yes, you bend the tab to adjust the height.

http://www.ducatitech.com/2v/img/float_height.jpg

[1fst400]

your my hero. Thanks man!!!

[ohsobad_chevy]

Originally posted by 1fst400
your my hero. Thanks man!!!

Yeah GPracer is a smart man, thanks for your knowledge and time, GP. You are a great resource. :)