jetting help needed

[rap169]

I know there are alot of jetting threads, but i read about every one of them and havent found my answer. I have a 450r with a hmf full exhaust and sparks air filter kit. I picked up a hrc kit and installed the lid and snorkel. IT ran great. I havnet installed the cam or jet kit at this point. Today i decided to put the hrc needle in. It made a great improvment in the midrange. Im very happy with that. BUt no i have a problem off idle. If the machine is is at idle and i chop the throttle it dies. If i take it slow its fine. So i originally thought maybe it wasnt warmed up all the way. SO i rode it around and went in the woods, and everytime i was in a sharp corner where i would almost be stopped , or i had the clutch in and the quad was at idle rpms, if i choped the trottle it would couch and die. Can anybody tell me if this is a lean condiotion, rich condition? And any suggestions to correct it. I have a 180 main, hrc needle, and air screw out 2.5 turns.
thanks

[RedRaider]

Mine was doing the exact same thing. I had my fuel screw at 2.5 turns out so i turned it in half a turn and it seemed to help.

[rap169]

so you think its a lean cough

[rowlrag]

drop the needle 1 groove meaning raise the clip for starters, made need 2. Your getting fuel to quickly and putting out the spark. The Hrc needle is thinner than the stocker so with the clip in the middle groove on both you get more fuel flow out of the main jet. With the cam installed you will be fine in the middle with a 185 and I use a 50 or a 52 pilot at times. The needle controls how much fuel is allowed through the main jet untill a bit before full throttle when it's completely out of the jet. Hope this helps. Air screw only controls idle quality to I'd say roughly 1/8th throttle.

[RedRaider]

Thats where mine was doing it was right off of idle which is the fuel screw because thats the only thing i changed other then the main and it never did it stock.

[rowlrag]

Originally posted by RedRaider
Thats where mine was doing it was right off of idle which is the fuel screw because thats the only thing i changed other then the main and it never did it stock.
Are you running the HRC needle also?

[RedRaider]

No i never did anything to the needle. It's still stock. Thats why i assumed it would be the air/fuel screw because i didn't think a main jet would have anything to do with the off idle throttle response.

[joe1l]

[QUOTE] i decided to put the hrc needle in. It made a great improvment in the midrange. Im very happy with that. BUt no i have a problem off idle. If the machine is is at idle and i chop the throttle it dies. If i take it slow its fine. So i originally thought maybe it wasnt warmed up all the way. SO i rode it around and went in the woods, and everytime i was in a sharp corner where i would almost be stopped , or i had the clutch in and the quad was at idle rpms, if i choped the trottle it would couch and die. Can anybody tell me if this is a lean condiotion, rich condition? And any suggestions to correct it. I have a 180 main, hrc needle, and air screw out 2.5 turns.

Are you running a an airbox lid or no airbx lid? I had a similar setup to you. I never had to change my airscrew setting, untill installed my cam. So i would turn back airscrew to the stock position. Also what clip position is your needle at, Mine is installed in the 3rd clip position. last, I would raise your manin jet to at least a 185, I was running a 185 with my cut lid and 188 with no lid.

[rowlrag]

Originally posted by RedRaider
No i never did anything to the needle. It's still stock. Thats why i assumed it would be the air/fuel screw because i didn't think a main jet would have anything to do with the off idle throttle response.
your right the main has nothing to do with off idle thats where the pilot jet takes effect, his problem from what he described is from to much fuel entering the engine for the stock cam can handle. The Hrc cam has more lift, if he lowers the needle 1 maybe 2 clips it should cure it, but go back to the middle clip after putting in the cam.

[rap169]

ok im using the hrc lid. I think my main is fine since it worked fine before i put the new needle in. I turned the air scre out 2.5 turns to get rid of the off throttle popping. Maybe ill try turning that in first before i tear it apart again. Otherwise i will try moving the clip down on the needle. When i put the hrc cam in, should i change it back and go with the larger jet?

[rowlrag]

Originally posted by rap169
ok im using the hrc lid. I think my main is fine since it worked fine before i put the new needle in. I turned the air scre out 2.5 turns to get rid of the off throttle popping. Maybe ill try turning that in first before i tear it apart again. Otherwise i will try moving the clip down on the needle. When i put the hrc cam in, should i change it back and go with the larger jet?

Move the clip UP meaning lower the needle, that will lean it out. When you put in the cam, start at 185 main that comes with it, air screw round 2-2 1/2 pilot stock is 48 get a 50, clip in the middle with the hrc needle.

[CatMostFeared]

do what rowlrag says he know his chit:blah:

[rowlrag]

get online hooo
:eek2: