I have a 96 Explorer 400 that will not start when I try to crank it. I can give it a shoot of starting fluid and she will crank right up. I can not get it to idle either. After I get it cranked it will run fine as long as I stay on the gas or if I am going at speed I can let off and it will not die until I come almost to a stop. I have removed the fuel line and filter going into the carb. They are both clean and I turned the petcock to on and fuel came out fine. So at first I was thinking that I had a fuel delivery problem since it would crank with the starting fluid. Now I am not so sure and I think that I might have a carb issue and that bothers me as I know almost nothing about carbs. I spent some time looking over old post that have to do with carbs and have gained a little knowledge on them. I have also enlisted the help of my father and am going to take the Explorer to him after work today. Any insight as to what to look for or adjust will be greatly appreciated.

Thanks in advance,
Richard

 

Is you idle set to low? Not sure how you set the idle on your carb but there is a way for sure. Two stokes must also have a clean air filter to run correctly.

 

I played with the idle yesterday and with it raised it more than a fair amount and it didn't help. I also cleaned the airfilter and tried to run it without the top on the airfilter box.

 

You should run a compression test on it. My 2000 xplorer 400 was doing the same thing. Mine had 115lbs of compression and wouldn't start unless i gave it a shot of starting fluid. Also you might check the etc and see if is functioning properly. If it isn't that would cause it to die suddenly. Good luck.

 

When you say the etc do you mean the elctrical? If so what part of it?

 

Sorry, the "etc" is the "electronic throttle control". It is the box for the thumb throttle. If something is wrong like the cable becomes loose the bike will die because of the etc. Take the cover off and start the bike. Then hold the cable and hit the throttle creating slack in the cable. If the etc is functioning properly the bike will die. There are little metal contacts in the etc and as soon as slack is in the cable they touch and make it die. Make sure they aren't touching to begin with. Also have you checked for weak spark? I had my spark plug cap loose and it wasn't making a good connection and it would run right at all. Make sure it is tight and you are getting 12 volts through the wire.

 

Before you use a whole can, STOP using starter fluid! It is a 2 strokes worst enemy. Starting fluid washes out the crank bearings. Use pre-mix in a squirt can.

You could have any of the above problems or you could even have a air leak and it is not creating enough vacuum to bring fuel into the cylinder.

 

Ok here is the update: Last night I took the carb off and cleaned it and went from a 200 main jet to a 220. I pulled and replaced the sparkplug (it had a lot of carbon build up on it). I put the carb back together and now she will fire up without any starting fluid and it will idle now although it is a little rough. I went down the street and it felt great on my way back from a rolling start I hit the gas wide open. It felt like it was building up and about to take off then it just died and wouldn't start again. Gave it a shot of starting fluid and it cranked up. I drove it back to the garage and put it up for the night.

A little history: I got a pipe from Rick Ritter @ RCR that I had installed a few months ago and never changed the jet. That is why I think that the carbon build up is so bad on the sparkplug although it could be from the starting fluid also. I will check the etc like meangreen said and will stop using the starting fluid and use pre-mix.

Any advice is welcome. Thanks Meangreen and Uflg

 

If you didn't jet the carb properly (Larger jet) when putting the pipe on you may have been running to lean (Would not cause a carbon buildup). Running lean means less fuel in the fuel + air mixture. This will cause the motor the get too hot causing damage to your top end. The reason you were provided with bigger jets with the pipe is because the new pipe changes the backpressures in your carburetion (Breaths better with more air). A bigger jet allows more fuel into the fuel + air mixture which will allow your motor to operate at a cooler temperature. You may now have to do a top end job.

 

The good news is,if he is right is that a top end job on a 2 stroke is no big deal. If it,s like my old moto crosser you get a one over sized piston,base and head gasket and wrist pin and the cylinder is bored out for the new piston size. A monkey can put it all back together if he has a wrench.[img]i/expressions/face-icon-small-wink.gif[/img]