450r hesitation off idle...

[bpimpdaddy21]

Hey all,
I just got a new '05 450R, and have a small trouble with it. It runs great, but has this very small hesitation. When you are sitting still, and you give it a little gas, rev it up, it hesitates slightly, then revs up. Same if you are in a low gear, if you give it quick gas it has a quick bog and then takes off. Could this be because there is not a lot of gas in it? Havent had a chance to fill it up, and its too late now to try it out on reserve. Or could my pilot screw be off? Any opinions are welcome. Thanks. Oh, there are only about a half hour on the quad, not even through break in yet, if that helps. Thanks.

You need to turn up you idle.

[bpimpdaddy21]

Its def not that, it idles just fine when it is warm, any higher would be too high, thanks for the input, but I am PRETTY sure its not the idle. It actually could be I am too lazy and need to put more gas in it, but ah well, or it might be the pilot screw, but just looking for other opinions. Thanks!

The idle should be 1600 RPM +or- 100.

[quad9]

mine did the same thing. adjust your mixture screw.

[bpimpdaddy21]

OK, so warm it up, then adjust mixture screw for highest rpm, the readjust idle, right? Thanks guys!

[quad9]

start the motor, let it warm up a little, shut it off,turn the screw all the way in. very slow!!
then turn it out 2 turns, start the motor back up, count the turns keep turning it out untill the motr idles rought, then turn it back slowly untill it smooths out. then adjust the idle. if you end up more than 2 3/4 turns out you need to put a 50 piolet jet in it.
if your bike is stock you should be right about 2 turns out.

[bpimpdaddy21]

Cool, thanks a bunch!

[bpimpdaddy21]

OK, so I adjusted the mixture screw. It was at 1.5 turns out, so I moved it to 2 turns, no change. I then changed out the spark plug, the stock one looked like crap, very carbony, but not wet. It seemed to be somewhat better with a new plug, but still there is a slight hesitation off idle. Anyone have any suggestions of something else to try? It is still under warranty, but dealer is 50 min away, wanna try and do this one myself.

BTW, the color of the plug (dark, very black on the end of threads and electrode) leads me to believe that the pilot screw may possibly be too rich. Is it possibly that the proper adjustment might be in to around 1.25 turns? Just a thought. The quad has been doing this since Day 1. Once you get past the hesitation the quad has all sorts of power. Any help is appreciated.

[HAVOK]

Mine had hesitation off idle, the choke was loose and letting air in and creating a lean condition.

[bpimpdaddy21]

Originally posted by HAVOK
Mine had hesitation off idle, the choke was loose and letting air in and creating a lean condition.

So did you just tighten the choke? Is there a way to do that? Lemme know! Thanks. I am going to try to get this taken care of myself so I don't have to take it back to the dealer. Thanks again.

[infantry317]

HMF says you can go 3.5 turns out max, after that increase Pilot jet.

[bpimpdaddy21]

I guess that the other thing is what were everyones pilot screws adjusted to from the factory? My brother has a 450r, his pilot screw is at 1.5 turns, and the thing runs mint. Mine runs the same as his, with the exception of the off idle hesitation. I will continue to look into this more, but keep the suggestions coming. Thanks!

EDIT: I might add that the quad, when starting for the first time of the day, always seems to start easier when I use the hot start. It won't start with the choke. If the bike is cold and I try to put the choke on right after I start it, the bike starts to run rough. It was about 85 out yesterday when I started it, and this was how I had to start it. Second kick holding the hot start, I then tried to engage the choke to get the idle up, and when I did this the quad ran rough, and whenever I would let off the gas it would quit. In a way this leads me to beleive that there may be air getting in somewhere else, which is cause the choke to maybe be "overchoking" the quad, if that is possible. It is just so annoying to have that hesitation right off idle. It only seems to do it when the quad gets warm too. It won't do it when the quad is cold. Once I get it up to temp, it starts to develope the hesitation.

Sorry for the long post, and I am not a newbie at this, I have the jetting on my 400EX down to a T, and this is just a new quad, and don't know it as well as the 400. Hence, I come to all of the people here for assistance. I appreciate any more help you can give. I am trying to clue everyone in as much as I can. Thanks again!

[trx450Rrider]

all you use the choke for is to start it when you havent warmed it up yet. DONT leave it on while its warming up. just let it idles for about 3 or 4 minutes then you can rev it alittle. all bikes run like crap with the choke on when the bike is basically warmed up.

[bpimpdaddy21]

Originally posted by trx450Rrider
all you use the choke for is to start it when you havent warmed it up yet. DONT leave it on while its warming up. just let it idles for about 3 or 4 minutes then you can rev it alittle. all bikes run like crap with the choke on when the bike is basically warmed up.

I gotcha, I was referring to right after I kick it over. If I put the choke on to start the bike, it wont start. Turn the choke off and push the hot start, it will start. And this is with a cold engine. Anyway, I am at a loss here for what to do.

[HAVOK]

Originally posted by bpimpdaddy21
So did you just tighten the choke? Is there a way to do that? Lemme know! Thanks. I am going to try to get this taken care of myself so I don't have to take it back to the dealer. Thanks again.

Yea it can be tightend up follow the chock lever to the carb and see if its tight. Mine was driving me crazy for weeks. took it to my dealer and they had it fixed in 20 min.

[03'400exrider]

I had a 07 450r and it did that very same thing...i bought the peice that was suppose to fix it (i cant remembe the same of it) but nothing i did could ever get rid of the bog. I finally got fed up with it and got rid of it....good luck

[ridding4fun]

Ok. as far as the hesitation off idle! This has to do with the amount of fuel an engine needs when you open the throttle. on the 06-08 450rs they arent getting enough fuel when you dump open the throttle. this creates a lean off idle mixture . you need to go smaller on the leak jet, this will increace the amount of fuel squirt into the intake when you blip the throttle. but not richen the rest of the rpm range . remember the smaller number leak jet the more fuel squirt. and as far as the plug being black, the only time you can do a plug read, is after you run the engine at full throttle and then do a ignition shut off . any time you run the engine slow or ride around the yard it will show a rich reading on the plug . hope this info helps . I have a 50 leak jet in my 06 and the hesatation is basicly gone.

this is on an 05 450r..it does not have the fcr carb with a leak jet, as ridding4fun suggested, nor can it use the quickshot like 03'400exrider was refering too.

but if you bought this new as a leftover, you have the stock carb on, it sounds as though there is a fuel delivery issue. i am actually leaning towards getting too much fuel, if you need to use the hotstart to start it when cold. i think what is happening is that when you stab the throttle, you are getting too much fuel and in effect, flooding the engine. just for grins and giggles, try starting it once with the airbox lid off. don't run it too long like that as it may be too lean that way...

[ridding4fun]

Sorry my bad,,, I was thinking it was an o6. dis-reguard what I said . :blah:

[adeezy9183]

hey guys i jus got an 07 450r and it is having the same problem with the hesitation as soon as u take off. i saw the post about the leak jet and was wondering if its hard to do. ive jetted a carb before but not on any of the new 450s. thatnks guys. any help is appreciated

it is easy...all you have to do is get a smaller leak jet...around a 55 or so...it don't really affect the a/f mixture like the 3 main circuits do...

[Sjorge450R]

i had a hesitation from idle until i switched to the HRC needle. Now, no problems at all :D

[adeezy9183]

I found the merge racing leak jet kit that is adjustable so you don't have to keep taking the carburetor off evertime you change the jet. is that worth it cuz it's like 144 bucks. but then 1 of you said that they changed to the hrc needle and it stopped it too. do i have to take the carb completely off or can i just loosen the clamps and turn it. i'm sorta limited on funds so i want to do the right thing first. thanks guys