My stock carb got ruined in a crash, so I replaced it with a Keihin PJ36. I was never happy with the stocker and heared the Keihin were a bit easier to work with. So I got it together and it starts much easier and runs better then it ever did with the stock, but I can't get it to idle. Gas also spills out the overflow hose whenever it isn't running and the gas is on. If I just keep my hand on the throttle it runs fine. What jets should I be using? Any help would be great. It has a DG Pipe and Silencer, open air box with a Uni filter, standard bore, PJ 36 carb, and a twist throttle.
Thanks

 

Would this be a pilot jet problem? If so how do I go about cleaning it, and how do I know if it should be replaced.

 

Dude you need to bash on someone or a quad make to get any answers , get people to veiw a fighting topic then you can get answers , I wrote a topic earlier called Rapters suck and got all the answers I needed my real question was KFX400 shock adjustment (help) and if you look at those no one responded like the raptors suck

 

I may have to try that. I use to be able to get all my questions answered before everyone got their Z's. You don't prove how good of a rider or what quad is the best on the boards.........you do it in the dunes and on the trails. I love my Z but I still need help keeping the old girl running. I'll give it a day or two......I still believe.......I will get the help I need!

 

Do you know how to adjust the rear suspension on the Z , mine likes to buck really bad

 

OK, calm down fella's........no need to bash to get a response.
87racerider, I don't know all the specifics of your problem with your carb, but it sounds to me like it may be a float problem. The floats may be getting stuck and allowing fuel to flow through the overflow lines. Try taking off the bowl of your carb and see if they are stuck, if so they may be out of adjustment or you may have some trash in there. I have changed from the Mikuni to a Keihin on my quadracer also and have had no problems. Did you buy the carb new or get it used?

Fst4wrd - sounds like you need to adjust the rebound on your rear shock. I'm not familiar with the KFX400, but I'm sure it is basically the same as most every other. What you need to do is find the rebound adjusting screw (which will probably be located on the bottom of the shock) and adjust it. I'm not sure which way is increasing or decreasing rebound on your quad, but the manual should show how to do it. Just give it a few clicks and push down on your quad and note how much faster or slower your quad returns to normal ride height. After a little tweaking you should be able to get it dialed in so it doesn't buck you off! There's a lot more to setting up your suspension than just that, but that should help you out.

 

Ok I took the carb apart and cleaned the jets and carb out. Gas is no lnoger leaking out the overflow but it still won't idle. Can the needle height effect the idle. What jets should I have in for that setup? Thanks

 

Hey 87RaceRider,

I had the same problem with my 86 racer. Here are the adjustments I made:

1. First of all make sure you have your air screw turned all the way in, then turn it out 1 1/2 to 2 turns.
2. Turn your idle screw all the way in, then turn it out 2 full turns.
3. Make sure your needle jet clip is set to the middle notch, then start it up and let it warm up good, you might have to hold your throttle to keep it running.
4. And finally after you get it running, adjust your throttle cable at the handle itself to the desired speed. There should be an adjustment wheel or nut where the cable goes into your throttle on the handlebars. You might have to hold the throttle a bit to keep it running, but adjust it to where you dont have to hold the throttle. I was so frustrated up until I realized I didn't adjust this. The handle adjustment should make it idle by itself. Good luck!

 

I had the same problem with my stock mikuni and my keihin PWK 36 I just put on a little bit ago. I now have my cases split because I had and airleak between the reed cage and cylinder letting in trap rock powder from the local quarry. I found that my pilot jet was clogged on the mikuni after I swtiched carbs and Have not got my motor back together yet to see if the air leak was the problem or if its the carb. My keihin is brand new. I don't have enough adjustment in my cable to just adjust that other wise I would have cheated and did that. Check out your pilot jet and if that doesn't work check for air leaks and here is a nice link I found for tuning keihin carbs http://www.duncanracing.com/techfaq/...-jetting.phtml this tells you what the symptoms of a lean and rich pilot jet and how to adjust the idle and everything else.

87RaceRider did you get my private message?

Hope this helps

chuck

 

The Keihin PJ carbs are not the best carbs when it comes to idling. If I remember correctly, there is not a seperate idle circuit. The PWK is a much better carb for idling and overall peformance. I have used the PJ in the past and never had any luck getting it to idle properly all the time.