2007 WR450F - Won't Run After Modifications
Posted July 02, 2009 - 11:56 AM
After it was all back together it would not fire up. I let it sit all night and tried it in the morning. It fired up but wouldn't run at idle and seemed to want to quit due possibly to lack of fuel. I opened the fuel screw a little more and it ran again but only if I held the hot start lever open even though it was not hot. Now I'm thinking that maybe it is getting too much fuel. I have no experience tuning the carb like this and was hoping for a little insight.
Thanks in advance.
Posted July 02, 2009 - 12:53 PM
Posted July 02, 2009 - 05:11 PM
By any chance did you remove the fuel screw at any time? Oring, washer and spring still in there? If the oring falls out it can cause problems with the idle mixture. It's tiny so you might not notice.
Adding hot start means leaning the mixture. You are getting too much fuel in the pilot circuit I believe.
Check the fuel screw for o-ring.
Posted July 04, 2009 - 04:52 AM
Posted July 04, 2009 - 10:27 AM
Posted July 04, 2009 - 10:50 AM
Any adjustments needed off of idle are either the needle or main jet.
Posted July 07, 2009 - 08:01 AM
Thanks - Thomas
Posted July 07, 2009 - 04:30 PM
what do you have in it for jets (I do not know what comes in the AIS kit...)
For a comparison, I have a 04 Canadian bike, no AIS, grey wire cut, air box cut outs, Hot cam's, and a FMF Ti powerCore, and JD Jetting, and am running a 170 main and I'm in Atlantic Canada at sea level, and cool conditions
Posted July 08, 2009 - 08:46 AM
I'll post again when I have my jetting info. Hopefully all I'll have to do is reinstall the old jets or something simple like that.
Thanks - Thomas
Posted July 08, 2009 - 08:57 AM
Do not think your losing out from the AIS removal kit, or that you got it for nothing. You need the AIS kit to get rid of the AIS, and the included jets are needed. But a JD Jet kit is what you need to sort out your jetting issues for temp and altitude (That is my opinion anyway).
To me, it does sound like you have jetting issues, and if so, the JD Kit will fix them, and his tech support is top notch and personal if you do have any little bugs to work out.
Posted July 21, 2009 - 10:06 AM
Posted July 21, 2009 - 10:23 AM
Posted July 21, 2009 - 10:28 AM
Posted July 21, 2009 - 11:01 AM
The original pilot jet was a 45 and the kit jet is a 50. My original main jet was a 162 and the kit jet is a 175. The original leak jet was a 60 and I don't know the number for the kit jet. There wasn't a main air jet before and the kit came with a 110. I installed all the kit jets. From the plug description someone told me they thought I was running lean and suggested reducing the size of my main air jet. Can someone steer me in the right direction? I'm sick of looking at my bike half torn apart in the garage. I want to go ride!
Wow, way too rich. Follow the advice above. I would go back to the 45 pilot and start working on that circuit. Search this forum or the jetting forum for "pilot circuit". Get that dialed in a little better. Then maybe try a 165 main. Not sure what the main air jet should be as I've never touched that one.
And I don't think looking at the plug is as reliable a source of info unless you are doing the plug/chop test.
Posted July 21, 2009 - 11:43 AM
Fuel Screw/Pilot Jet
Fuel screw settings in the 'book' are recommended starting points. Every bike is different, as is the temp and altitude. Set the screw according to this method.
Gently turn the screw all the way in. Now back it out two turns. Start the bike and fully warm it up, go for a 10 minute ride. Set the idle to speed to 1,500~1,800 RPM as best you can (I know, without a tach this is tough, just set it to were it idles relatively smoothly). Once warmed, slow the idle to the lowest possible speed.
*** When turning the fuel screw, keep an accurate 'count' of the amount you are turning it and record it in case you have to reset it for some reason. Makes life easier when you can just set it from notes Vs. going through the procedure again.***
Turn the screw in until the idle becomes rough or the bike stalls.
if it stalled, open the screw about 1/4 more turn. Restart it and slowly screw it in till you can just perceive a change.
If the screw can be turned all the way in and the bike still idles perfectly and does not stall, then you need to go down a size in pilot jet.
Now very slowly, open the fuel screw till the idle is smooth. Blip the throttle, let the bike return to an idle, wait say ten seconds. Confirm it is the same smooth idle.
If the screw has to be opened more than 3 turns to get a smooth idle, you need to go up a size in pilot jet.
If you find it does not stall with the larger jet but has to be open more than three turns with the smaller pilot jet, put the larger one in and set the fuel screw at 1/2 turn.
If the idle speed increased, adjust the idle speed knob to return the bike to a real slow idle speed. You must then re-visit the fuel screw. Keep doing this till the fuel screw is opened just enough to provide a nice steady idle at the lowest possible RPM. Once this is done, increase the idle speed to the normal one for your bike, typically about 1,800 rpm, but go by the spec in your manual.
Posted July 21, 2009 - 11:55 AM
It's good advice. You owe a couple of guys some good gas for their time.
Posted July 21, 2009 - 01:38 PM
You need to decide how much your time is worth now.
Time is what your going to invest in dialing in your jetting so it is where it should be to match your area.
I still humbly suggest you consider the JD Jet kit for your bike, as it pretty much takes the guess work out. I'm not saying you can't get it dialed in on your own, but it will take considerable investment in time.
For me, the cost of the jet kit more then offset the time investment I would have had to make. JD's instructions are spot on from my experience, and from what I hear from MOST others (Can't please everyone all the time), and his customer service/support can't be beat.
Posted July 22, 2009 - 09:18 AM
Posted August 04, 2009 - 10:12 AM
Thanks in advance.