Helping a Friend w/Jetting

[CJM]

Buddy of mine just got an 09 and they threw in the HRC kit, KN powerlid, as well as a FMF exhaust, they also jetted it for him.

He has a very bad low bog, once he gets past 1/3 to 1/2 throttle its ok tho. He said they used some FMF "power up" jets that came with the pipe.

Im thinking he needs to use keihin jets and throw out these stupid FMF jets. The paper he has states he has a 135 main. Not sure if they changed much else.

Any recommendations on jetting, pilot size and a/f screw settings. Ive never worked on this new of a 450R before so Im stumped. Elevation is 500ft above seat level.

[desratt]

the hrc jetting is way better . if he bought the hrc kit and they didn't use the jets and pipe he should ask for them.

[CJM]

See thats what I dont get, they didnt give him anything afaik besides the quad back.

[DnB_racing]

Originally posted by CJM
Buddy of mine just got an 09 and they threw in the HRC kit, KN powerlid, as well as a FMF exhaust, they also jetted it for him.

He has a very bad low bog, once he gets past 1/3 to 1/2 throttle its ok tho. He said they used some FMF "power up" jets that came with the pipe.

Im thinking he needs to use keihin jets and throw out these stupid FMF jets. The paper he has states he has a 135 main. Not sure if they changed much else.

Any recommendations on jetting, pilot size and a/f screw settings. Ive never worked on this new of a 450R before so Im stumped. Elevation is 500ft above seat level. if its bogging at that throttle location then its a good chance its to rich on the needle..


but the funny part is you have a real good explination in your sig,lol

[CJM]

It indeed is, I just dont know much about the newer 450R carbs or where to have them set roughly for a 450 machine since I generally work on 400ex's. Was looking for starting suggestions more than anything else.

Also wanted to know what the stock jet size was too, if anyone knows.

[DnB_racing]

you might want to try raising the needle first, to lean it out.

if its running ok on top end then the main is fine

stock main is I think 120 wich is really to lean any ways

I would guess around a 155 main 48 pilot and air screw 2 turns and needle middle, but as you already know this is strictly a guess, the only real way is the plug chop and actually running the quad with whatever mods and gas and filter he has

the fcr carbs are real easy if you have been working on 400ex then you will pick it right up...I have a pretty highly modded 450 and im running a 168 main and 48 pilot a hrc needle in the middle air 2 turns

and its an air screw on the 450, im not sure if the ex is air or fuel, but just making sure you have the info for the 450

[desratt]

also the accelerator pump adjustment and leak jet.. all comes with the hrc kit

[speedracer350X]

Yea, don't forget the acc pump adjust. Look on 450r.org, type in HRC kit install manual, read the instructions, really guided me along, fought that bog for 2 years or so.