JD---your kit for CRF450
Posted 16 October 2003 - 08:53 AM
I am fairly comfortable with setting up my jetting, since I am sea level and fairly consistent humidity. I tested sevel different mains ona dyno a few months back, and found that even with my TA pipe on, stock was best, especially on the low end, there was a very small gain on top using a 175 but it was blubbery down low. Someone suggested to me at the time to try the 175 again but drop the needle 1 or 2 clips to regain the low end, but alas, dyno time was limited and there was no way I could swap needles or clip positions.
...is this sound advice?
Right now I am currently running the settings with a 172 main (170 stock)and the pilot screw 1/4 turn richer for the cooler weather we are having finally.
I tried the 175 last weekend with the needle dropped 1 position, but it seemed to be flat on the bottom before it came alive...of course humidity was literally 100%...I can figure for incremental temp changes, but how large of a percentage does humidity play? I mean, with a 20f drop in temp I know to go richer on main and pilot, but if the humidity goes up from 60% to 100%, does that negate the need for richer jetting since the water content cuts back on the O2 content, effectively "balancing out" the temp change?
Sorry to be long winded, any help would be appreciated, and would your jet kit be beneficial to me?
Posted 16 October 2003 - 09:38 PM
The kit helps transition stronger off the bottom and mid-range, and lean the top-end. The CRF has more potential than most riders realize.
Posted 17 October 2003 - 08:04 AM
Maybe you haven't spent much time in South Texas! Humidity can change from day to day dramatically. One day, dry and cool, the next warm and muggy.