rossier... problems with jetting!

[taylorman08]

hi, i just bought a rossier exhaust for my 450r and i'M really busy on which jets to use... i saw the precision motorsport shootout with the pulse charger and the rossier, but the 450 was having a 13.8:1 hi comp piston, so i think it change the jetting... I need to know which main, pilot and needle and air screw i should be running...Also, i have no air box lid. i know this kind of tread is really tiring, but i didn't found something in past treads! thanks a lot!!

[Big Slick]

How hard would it be for Rossier to include a jetting guideline with their exhaust. Hell, even LRD gives jetting guidelines.

I'd start somewhere around 180 on the main jet, Needle 3rd clip, 2-3 turns out on the fuel screw.

Then read this http://www.trx450r.org/forum/index.php?showtopic=1657

[ESrider]

I would start a little higher, say with a 190 main and a 50 pilot, depending on your elevation. I'm at sea level running a 180 main with just a cut airbox lid and the spark arrestor removed. I like to start rich and work down if needed.

[MR.BIG]

I would also say start with a 190 main. I am running the hrc kit with there needle in the 3rd position. Why don't you call rossier and ask them for the jetting specs?

[taylorman08]

i'M living in quebec, so the elevation isn't really high!
Does it really help to put an aftermaket needle? or the stock would be okay?? thanks!

[Got nads?]

I live in Alberta and I am running a 180 main with my Rossier and Hot cams stage 2, K&N air filter, and I'm thinking about dropping it to a 172- 175. I have the needle on th 2nd clip. Oh yeah when I bought the rossier I recieved jetting reccomendations with my instructions if though they were for 700-1000ft above sea level!

[brandonpeake]

give joe a call he is one of the most helpfull people ive ever talked with on the phone it dpeends on your altitude, i live in the south east and have a 190 main a 52 pilot and sparks needle on 4th clip i believe and it runs outr great and passes the spark pluig test, and im running hrc style air box 13-1 je , port and polish hot cam stage 2, rossier full system

I live in minnesota, and the jetting does come with the pipes, for my set up no lid clip in the 3rd pos. and a 50 pilot with a 185 main, and i use a sparks cam, but jetting really won't be affected by the cam.
jasson

[wppracing]

I did the pipe shoot out with my Wppracing 450R. Precision Motorsports supplied the dyno service.
What mods have you done and where do you live. I have any jet combo you will need .

[taylorman08]

the only mods on my bike are the full rossier pipe and no lid... I live in the south of the Quebec, near montreal, so like i said, the altitude isn't really high! thanks

[wppracing]

You are only going to get so much from a pipe only. I would at the least install a cam either the HRC or the Hot Cam Stage 2
Replace the stock air filter also. With a pipe only , try a 180 main,
air screw at 2.5 turns open and the needle clip on the middle slot. Then try the clip on the 4th slot.

[Jonas]

Have you seen dyno proof that your uni filter is better than a stock filter?

[taylorman08]

i was looking for a cam, but none of them are available at this time of the year! The first race of the year is next week, thats why i asked about what jet to run with a pipe only! Wppracing, what cam would be the best for me... i'm only doing mx, so i cant sacrifice my low end and i dont want to purchase a hi-comp piston... I was looking for the hotcam stage 2, but is there something better?!

02 crf cam, and the rossier cam is good to.

[TRXDresh]

Rossier does give jetting guidlines in the instructions. I know cause I have 2.