help!

[dxcody]

ok guys, i made a mistake... dont hurt me. but i traded my 400 for a yfz 450.. i know, i screwed up. i posted a thread on yfzcentral but i havent gotten any replies.. any. so when i bought it it wouldnt start. i got it started, and with the choke on it idles decent. when you turn the choke off it will die, but if you hit the gas it revs way up then dies... and when i keep it reved, its fine... so i tried to take off last night.. clicked it down in first and started letting out on the clutch and the machine doesnt start moving until you have the clutch lever 7/8 of the way out and when you let it out all the way it just shuts off. it doesnt matter if you have the throttle pinned it shuts off. it doesnt act like im killing it, it really just turns the motor off it seems like.. any ideas?? :(

[01boneless]

start by cleaning the carb it could easyly be the problem if not report back and ill try to help ya out tho i dont no much about yfz's

[dxcody]

Originally posted by 01boneless
start by cleaning the carb it could easyly be the problem if not report back and ill try to help ya out tho i dont no much about yfz's

ok thank you for the reply, i am going out to clean out the carb now. sorry about the yfz on a honda site but no one will reply on the yamaha site. i will let you know how it goes. thanks again.

[01boneless]

Originally posted by dxcody
ok thank you for the reply, i am going out to clean out the carb now. sorry about the yfz on a honda site but no one will reply on the yamaha site. i will let you know how it goes. thanks again.

no prob bud

[rtrocket59]

try checking the spark plug

[dxcody]

Originally posted by rtrocket59
try checking the spark plug
when i bought it, it had no spark, bought a new plug and thats when it fired up.

[wilkin250r]

Originally posted by dxcody
sorry about the yfz on a honda site

No problems. We started out as a honda site, but we've evolved and grown beyond that, there's room for all brands on here.

I think a carb clean is in order, and let us know what your jetting is.

[dxcody]

Originally posted by wilkin250r
No problems. We started out as a honda site, but we've evolved and grown beyond that, there's room for all brands on here.

I think a carb clean is in order, and let us know what your jetting is.

i cleaned the carb, havent got a chance to start it yet, (i am going to a midwest cross country race) just as a spectator.. but im sure that helped.. it has a full curtis sparks exhaust with a shorty pipe. the main jet is a 168, and there is a symbol on it that looks like the alpinestar symbol. idk what that is but "supposably" its jetted.. thats just what the old owner said. i pulled all the jets out and cleaned them and blew them out, put all of them as tight as they go, then backed them all out 2 1/2 turns out. should that be enough to get it started?

[01boneless]

Originally posted by dxcody
i cleaned the carb, havent got a chance to start it yet, (i am going to a midwest cross country race) just as a spectator.. but im sure that helped.. it has a full curtis sparks exhaust with a shorty pipe. the main jet is a 168, and there is a symbol on it that looks like the alpinestar symbol. idk what that is but "supposably" its jetted.. thats just what the old owner said. i pulled all the jets out and cleaned them and blew them out, put all of them as tight as they go, then backed them all out 2 1/2 turns out. should that be enough to get it started?

it should

[matts27]

i got it started, and with the choke on it idles decent. when you turn the choke off it will die, but if you hit the gas it revs way up then dies... and when i keep it reved, its fine...



I would guess it has a vacuum leak on the intake boot. Get it running and spray carb cleaner around the front of the carb towards the head. If that checks out than the venturi on the carb may be sticking, I'm assuming that it's a mikuni carb. Hope this helps, Matt

[dxcody]

Originally posted by 01boneless
start by cleaning the carb it could easyly be the problem if not report back and ill try to help ya out tho i dont no much about yfz's

ok, she fired right up, idles great now, almost like new... still shuts off when you try to go.

:ermm:

[01boneless]

Originally posted by dxcody
ok, she fired right up, idles great now, almost like new... still shuts off when you try to go.

:ermm:

huhh does the clutch arm on the clutch case sqeze it when you pull the clutch? if not try to adjust the clutch does it just die or try to go and stall?? im here till 11 tonite bro answer back

[dxcody]

Originally posted by 01boneless
huhh does the clutch arm on the clutch case sqeze it when you pull the clutch? if not try to adjust the clutch does it just die or try to go and stall?? im here till 11 tonite bro answer back

it doesnt kick forward like if its just dumping the clutch, the motor just shuts down. i dont get it!!!

[01boneless]

Originally posted by dxcody
it doesnt kick forward like if its just dumping the clutch, the motor just shuts down. i dont get it!!!

i hate to tell ya to go out in the dark lol but i need to know is the clutch are is engaging:confused:


read the desciption for the vid is this what urs is doing??

http://www.youtube.com/watch?v=2LAOjL_Tc0c

[dxcody]

Originally posted by 01boneless
i hate to tell ya to go out in the dark lol but i need to know is the clutch are is engaging:confused:


read the desciption for the vid is this what urs is doing??

http://www.youtube.com/watch?v=2LAOjL_Tc0c
yes it is engaging, i even pulled the cover off to make sure.. and no thats not wat is happening.. like i said the motor just shuts off when u try to take off..

[01boneless]

Originally posted by dxcody
yes it is engaging, i even pulled the cover off to make sure.. and no thats not wat is happening.. like i said the motor just shuts off when u try to take off..

huhh sounds like a electrical prob but im not sure sorry i couldent help ya maby call the dealer and tell them what its doing