300ex Won't Start!

[XCAdam89]

Here's the deal, I just got my shocks put back on after getting rebuilt and I took it for a spin around my front yard. There wasn't hardly any gas in it at all in the first place, it was on reserve.

While I was riding, I shifted down from 3rd to second and it made a whining sound, and then quit. I figured it just ran out of gas, but I went and got brand new gas and it still won't start.

I tried jumping it earlier, and it started, but then quickly died out after. Any Idea what it could be? I haven't ridden in over a month and I'm pretty anxious to go ride again.

Today I pulled the spark plug, and it's running rich. My dad left the key on a little while ago, and the battery was ran completely dead not too long ago as well, but it started before after being jumped.

Also, it seems to me it's stumbling a little bit when revved, I'm guessing the carb needs cleaned, but do you have to completely take it off to do so??

Any help is great.

[330ex51]

to clean the carb you are going to have to take it off. Make sure that you clean it good while you have it off caz it is a lot of work to go through if you dont get it right.

Also you say it fires but wont stay running? make sure you have gas getting to it.

[XCAdam89]

It will fire sometimes when I have jumper cables connected to it, but it won't fire at all on it's own. It's turning over, but it just won't fire.

Also, when it is running it seems that it wants to stay running, but not enough gas is getting to it and it just dies off. What could cause that?

I know it's running a little rich too, the plug was black, I guess I'll play with the airscrew tomorrow.

[330ex51]

there are some other posts that talk about some connections that may need to be so you get full connection may want to look at those. Also do you know your battery is good caz I had that problem and it was caz my battery posts were bad, so it would only start when on the charger.

[330ex51]

i was going to tell you too to try that other stuff before doing the air screw caz it sucks getting the carb right on again trust me!

[XCAdam89]

What connections? Is there a filter on the bottom of the gas tank that could be clogged? I know someone said it sounded like the pilot jet was clogged.

[330ex51]

I dont know what you have for a filter but I put a big fuel filter between my gas tank and carb. if you have one you could look at it.

You can make sure it is not the fitting on your gas tank by disconecting your tank from the carb and turn gas on and make sure it runs out in a good stream. If you think it is that.

To check your piolt you will have to take your carb off and just take out the jets and see if they are clogged. I had that problem. If it is your piolt your quad will dog when you hit the gas.

It is not hard to do those things and not a bad idea to clean the carb if you have never done it.

Do you know why they said it sounded like a piolt jet?

[bwamos]

The 300ex has a fuel filter screen in the petcock. Remove the tank and on the bottom there be a plug on the bottom of the petcock (a lot liek the main jet plu gon the carb). Unscrew it and theres a screen there you can clean and put back in.

But, that's not your issue.

You have a bad battery. (It was run to dead and left sit). It's not holding charge anymore. That's why it will sometimes start on a charger.

Buy a $10-$15 battery tender for your future batterys, hook it up when you put it away. ;)

[XCAdam89]

Originally posted by bwamos
The 300ex has a fuel filter screen in the petcock. Remove the tank and on the bottom there be a plug on the bottom of the petcock (a lot liek the main jet plu gon the carb). Unscrew it and theres a screen there you can clean and put back in.

But, that's not your issue.

You have a bad battery. (It was run to dead and left sit). It's not holding charge anymore. That's why it will sometimes start on a charger.

Buy a $10-$15 battery tender for your future batterys, hook it up when you put it away. ;)

That's what I thought as far as the starting was concerned, thanks. But for the issue of it starting and then dying (Like it's not getting the gas it needs) could that be the fuel screen like you mentioned?

I know it's running rich as well, Anyone care to give me a jetting 101 tutorial? Do you have to have the carb off to jet it?

[330ex51]

Yeah you have to have the carb off change jets

[XCAdam89]

Well I got her running today, I had to use jumper cables to do so though. I changed the spark plug, and then ran some carb cleaner fuel additive to the gas, and let it run for a few minutes. It seems everything is cleaned out now, and it runs fine.

The quad still doesn't start on it's own, so I'm going to get a new battery this week.

I have another quick ? though, where exactly is the fuel screw on the bottom of the carb? Is it turned by a flat or phillips screwdriver? What direction leans the motor?

[XCAdam89]

ttt