OK guys. I searched this and found only 1 other problem that matched my problem and there was only 1 reply and that didn't really help. Here is my problem my quad will start "believe it or not", but when I let up off the start button it dies. I have checked wiring, and clutch switch, and neutral switch, this is all working properly. I have not tried to push start it because I have no wheels for it right now. Also 1 time I was trying to start it the darn tachometer sparked out and now it doesn't work. I thought that might be a problem so I unhooked it, still doin it. I am about to blow my top. I have looked the wiring scematic over and can't see what would be doin it. It is like I am killing power to the ignition when I let off the button but yet all the lights are lit up. I am really confused and would really like for someone that had this same problem let me know what they did to fix it. I am sure that someone out there has either had this problem or knows of it and hopefully can help. By the way it is a 2003 ds650 baja. Also it has started normally before and seems to maybe be intermitten, in other words it has done this and then started right and then not right. Please help. RUSS

 

and you are sure it's getting fuel?

 

Yes I am sure it is getting fuel. It will run as long as I want to hold the start button. Very confusing huh. Let off the button it dies imediatly. I have one other thing to try but not sure where that will get me. It has spark,gas,compression, and will run as long as I hold the start button.????????????????????

 

Sounds like a fuel problem. This is the same symptom as running out of gas on the trail. It will fire on a very lean mixture as long as the starter is there to help, but dies when the starter is released. Basically it's running on vapor.

It sounds like you have been working on it. I'm not sure how pc or safe this is, but pull the air filter and spray carb cleaner into the carb as you turn over the engine. If it tries to start (or starts) when you do this, you will know it is a fuel problem. It does not sound like a spark issue at all.

 

Do the carb cleaner trick as mentioned above to rule out a fuel problem or not . It's safe and a very commonly used practice ! just use common sense and don't smoke while doing this , or put your face at the airbox/carb to see anything (if it backfires you will melt all the hair off your face and head will catch on fire !!!!!!!!!!!! ) Have fun !!!!!!!!!!

 

Russ,
you keep saying it will run. Does RUN mean you can give it throttle and rev it up and hold rpm? Or does RUN mean it just idles and when you go to throttle up it dies?

 

Thanks for your imput guys and not to be rude but you need to read the post a little closer if ya wanna help. I am definatly not unmechanicaly inclined. I have built many race cars and have worked on cars for years. I know you all are not trying to say that I am dumb or anything but I have went through what I know to do. There is one thing that I hav'nt went through yet but was hoping someone could tell me what the problem is and not really what to try. I do appreciate all the comments and hope you all understand that I don't mean to make you think I am a know it all because I'm not. But if you read the post it tells the story. Again thank you all that have replied and to future replies and if I figure it out, I will surelly post it, but in the meantime please don't hesitate to let me know what you think or know the problem is. RUSS

 

Russ it seems to me that it is a wiring/electrical problem. I feel that you will find your problem here because the start button and the kill button are located here. Have you had the wiring/ switches off or apart? When you have the start button pushed it closes the circut and allows it to run and when you let off the button you then open the circut, LOOk into this make sure you check you switches to make sure that they are not bad.. good luck, john

 

Russ, I have read again and still am asking the same question. If you hold the starter button:
Will it RUN like normal?
Can you throttle it up and hold rpm?
Can you see the slide going up in the carb when applying throttle?
Not trying to say you are less than anything but smart. I jst ask because I had a similar sounding problem with my DS and it turned out to be a screwed up slide.

 

Russ,

mudnuri has a very valid qusetion. We ARE trying to help, your problem sounds complex and we need more information. If you want help from us we need your help telling us EXACTLY what it is doing. Thats all. I would check the carb, make sure it is opening. Then, Check for spark, you have two plug wires, it will run on one. Hook the easiest one to get to, to a spark tester. See if the spark dies after you let off of the start button.
If it does, you need to check for 12V on the + side of the coils. I think your problem is in the switch cluster as well.