Another 04/05 450r carb ?

[qlphoton]

Ive got the carb on ,and the bike seems to run ok.Im starting to tune it.I have put a 52pilot in and adjusted the a/f screw to highest idle which is 1and3/4 out.When i stab the throttle quickly ,in the first1/4of it ,it wants to die.And i do mean stab quickly.Maybe this is just me,but that bothers me.Is this normal?

[Stickman400]

Are you stabbing from 0/4 throttle to open? Or are you going from slightly open to fully open? If you are doing the first way then that is normal, there is always going to be a hiccup when you do that on a normal slide operated carb. If you are doing it the second way then that is more than likely your needle. Prolly needs moved down to the 4th notch if you haven't touched it.

[qlphoton]

Its the first and thats what i needed to know thnks

[MEOFF]

i was having the same problem with mine and my problem was the needle i'm running a 50 pilot and a 178 main and my fuel screw is at 2 1/2 out right now i hane the stock needle out of my 400ex in the 3rd clip and its alot better right now but i'm waitin on fine tunning it til i find out more abou the needle

[hondaREX]

I was asking about the same issue in my post. And nobody came up with its normal. I was starting to think I was going to have to deal with it and I wasn't too upset because it runs awesome all other times except when I crack it open quick. Figured I'd just be on the throttle the whole time!! So the trick is to stay on the throttle slightly and crack it from there? And Stickman, you say this is normal with the 450r carbs? Does the same happen with the EX carb? Maybe I just lived with it b4 and since I am tuning the 450r carb, I thought it shouldn't be.

[CJM]

When idling if you crack the throttle there is a slight delay in the fuel reaching the carb.

Im not sure if it really helped me, but when I crack mine so long as its warmed up its fine. But I did take off the side cover and bend slide that touches the accelerator pump. its touching it now slightly.

[JOHNDOE83]

well, I know not all motors and tuners are the same.

My 440 with a 05 450r carb runs a 50 pilot, 3 turns out, 3rd notch and I dont have any hiccups or bogs, from 0 to full throttle instantly with no problems.

hiccup or a bog is generally a lean condition but could also be related to being to rich in some cases.

You'll just have to play with tunning a lil bit to get it right or you'll have to deal with it, it wont hurt anything if you leave it like that.

Try going 2.5 or 3 turns out on the screw and see if that bog goes away.

[hondaREX]

My next attempt is to go up to a 52 pilot. I'm at 3 turns with a 50 now. Still haven't been actually riding with it yet but I might have to deal with it if it's not that bad. Going to try CJMs trick under the side cover.

[Stickman400]

I can't remember what it was called or where I read it but someone like Mikey Dunlap or someone wrote an article describing what was happening and why. It was something along the lines of when you stab the throttle from none to 3/4 or WOT it creates a sudden lean condition that the carb. cannot cope with for that split second and that is the delay from the accelerator pump. But after that split second the fuel from the accelerator pump reaches the engine and it picks up and takes off. Again I can't remember exactly what it was but it was something along those lines. Don't beat me to death if you find the article and I'm wrong about some part of that.

[Stickman400]

I forgot to add that this only happens on carbs. that have a round slide. FCR carbs. and similar carbs. with a flat slide don't seem to suffer from this problem.