400ex wont start after sitting for a while

[drew3623]

Hey guys, can you help me out here please?

I have a 2005 400ex. Only thing aftermarket is exhaust. I only started it about 2 or 3 times last winter and that was only for about 5min each. Over the summer only once. I went out last week to get it running and the battery was dead. I jumped it and got it to start for about 2 sec (this happens every time since new until it warms up) and died. I kept doing it for about 3 times. Then it would crank, but not start.

So I bought a new spark plug with no luck. Then we drained the gas and put new in it. Still no luck. We then took off the top plate off the carb (it was clean inside) and sprayed carb cleaner in it to get it to turn over. It sputtered but then died.

I know we had spark. It seemed like it just wasnt getting fuel somewhere.

Any advice on what it might be? Should I try cleaning the carb even though the top looked clean?

I am not a smart guy when it comes to this stuff, so I had my bro in law helping me.

Thanks guys!

[2001400exrida]

when you put the aftermarket exhaust on did you rejet. the 400's are cold blooded and lean from the factory. First and best mod is to up your pilot jet a couple sizes it really helps with cold starting. when you spray carb cleaner in to help starting make sure you spray it from the intake. also make sure your obvious things are checked, petcock is on, plenty of fuel, etc.

[drew3623]

when you put the aftermarket exhaust on did you rejet. the 400's are cold blooded and lean from the factory. First and best mod is to up your pilot jet a couple sizes it really helps with cold starting. when you spray carb cleaner in to help starting make sure you spray it from the intake. also make sure your obvious things are checked, petcock is on, plenty of fuel, etc.

Thanks for the reply!

I did rejet it. I dont remember what I used, but I recieved help from this forum. I did that about 3 years ago. I checked all the usual things. And I did spray from the exhaust to try to start it and that is when it tried to start. But once that was burnt off it died.

It always take a little while to get started after not riding for a while, but usually it ends up firing and running. So Im kind of lost now.

[DragonGunner]

Thanks for the reply!

I did rejet it. I dont remember what I used, but I recieved help from this forum. I did that about 3 years ago. I checked all the usual things. And I did spray from the exhaust to try to start it and that is when it tried to start. But once that was burnt off it died.

It always take a little while to get started after not riding for a while, but usually it ends up firing and running. So Im kind of lost now.


Old gas = gummed up and varnished carb. take carb off, drop the float bowl and clean with carb cleaner in every spot, take out jets and clean and make sure they are clear. Turn air screw in all the way, count the turns. Screw it out with the spring and clean in there, put back in and count turns so its back in the same spot.....I bet if you go out and TRY and flood it, pump like crazy and if it doesn't start pull the plug, if it ain't soaked with gas its your carb for sure....also I let a carb set for over a year and also had to take the excelarater pump apart and clean, was nasty.....

[CJM]

Gonna hafta clean the carb totally out. Remove it and clean every single orifice possible. Make sure you remove the accelerator pump and clean that too.

[400man]

sounds like its the carb deffinatlly. when you get it lined out and running.....ride the $#it out of it!