Thoughts needed 2007 crf 150r jd kit just installed
Posted: Tue Sep 14, 2010 7:06 pm
Here are the specs:
Location: Orlando, Florida
Temps: 90 plus
Elevation: sea level to 200'
main jet: 145 per JD crf's only
pilot jet : 42 per JD crf's only
jet needle: red needle 5th positon from top per JDcrf's only
fuel screw: 2 turns out flex fuel screw crf's only
Leak jet: 45
Ap cover; boyesen QS2
Ap mod: yes thick o ring
TPS: set @700 ohms black to yellow.
Airfilter: twin air
Backfire screen: stock
Exhaust: FMF power core 4 slip on
Pipe; stock
works connection: tach/hr meter
Went for a test ride short. Don't want to stir the neighbors have to wait til Saturday for full test at the trails. First initial thought about JD kit was okay solved small bog off idle. Might be a combination of the larger main jet and the jet needle diameter. Already had the QS2 and ap mod so that did not change. Did change the leak jet to 45 to increase the squirt. My only beef left is the idle and low end response. After 1/4 throttle it rips. I have used in the past 40, 45,48,50,52 pilots and they made the idle smooth but had a little bog. Too small and you get a hanging idle because the slide cutaway influences the transition. Too big a pilot and the slide is too closed and you get a slow response
when cracking throttle open from full closed.
Now my problem is no bog but hanging idle. I can increase the pilot but in doing so the idle is perfect but the circuit is rich and hot starts become an issue after the engine is hot. You have to hold the hot start and give 3 kicks and it fires up.Because of the richness of the start circuit. I am tempted to go down one size on the pilot air jet on the intake side. Factory service manual says idle rpm 2100 + or - 100 rpms. When i attempt this using the works conection tach, things get interesting. I know a bunch of folks set their idle to what sounds best but it would be nice to know that you are in idle speed rpm and have everything working.
Location: Orlando, Florida
Temps: 90 plus
Elevation: sea level to 200'
main jet: 145 per JD crf's only
pilot jet : 42 per JD crf's only
jet needle: red needle 5th positon from top per JDcrf's only
fuel screw: 2 turns out flex fuel screw crf's only
Leak jet: 45
Ap cover; boyesen QS2
Ap mod: yes thick o ring
TPS: set @700 ohms black to yellow.
Airfilter: twin air
Backfire screen: stock
Exhaust: FMF power core 4 slip on
Pipe; stock
works connection: tach/hr meter
Went for a test ride short. Don't want to stir the neighbors have to wait til Saturday for full test at the trails. First initial thought about JD kit was okay solved small bog off idle. Might be a combination of the larger main jet and the jet needle diameter. Already had the QS2 and ap mod so that did not change. Did change the leak jet to 45 to increase the squirt. My only beef left is the idle and low end response. After 1/4 throttle it rips. I have used in the past 40, 45,48,50,52 pilots and they made the idle smooth but had a little bog. Too small and you get a hanging idle because the slide cutaway influences the transition. Too big a pilot and the slide is too closed and you get a slow response
when cracking throttle open from full closed.
Now my problem is no bog but hanging idle. I can increase the pilot but in doing so the idle is perfect but the circuit is rich and hot starts become an issue after the engine is hot. You have to hold the hot start and give 3 kicks and it fires up.Because of the richness of the start circuit. I am tempted to go down one size on the pilot air jet on the intake side. Factory service manual says idle rpm 2100 + or - 100 rpms. When i attempt this using the works conection tach, things get interesting. I know a bunch of folks set their idle to what sounds best but it would be nice to know that you are in idle speed rpm and have everything working.