just a jetting ?

[StuckInTheMud]

ok, i have a 05 450r with a dr. d slip on pipe. a je 13 to 1 piston, stage 1 hot cam, port and polish, uni filter with the lid off, right now im at a 178 main with a 52 pilot, i think its off a little bit and i think i need to go to a 50 pilot, any input?

[Toadz400]

How is it running? You'll probably be better off with a 50 pilot, or possibly even a 48. What's your needle at? What's your elevation and the temperature?

[StuckInTheMud]

well it seems alright except i dont think i need that much fuel pushing through and it runs reali hot with just a slip on and right now i dont have the $ for a full system , im not sure on the elevation and for running the 48 pilot, thats stock and it wouldnt run with a 48 so i went bigger...im going to get a 50

[Toadz400]

Oh wow, didn't know there was that big a of a difference in pilot jet size between the YFZ and 450R carb, didn't think the few mm's made that big of a difference.

Anyway, try the 50 pilot and see how it starts and runs at low throttle with that. You say it runs really hot? That would indicate that you're running lean somewhere in your jetting, more than likely the throttle range that you are in more often.

[StuckInTheMud]

yeah its more low end lag at first then right when i pin it and the rev kicks it. my bike is set up for harescrambles X/C but man i like to drag race too, im going to have to get this dialed in better

[krt400ex]

if it lags off the bottom then it is lean. especially with a stage 1 hotcam because those r made to improve bottom on the 450r. go up on ur pilot. and mess with ur fuel screw. sounds like it needs to be richer

[Toadz400]

The FCR's also have a problem with the leak jet being too big, which causes the bog experienced when you jab the throttle at low RPM's. Do a search on the FCR leak jet and it should help you out.