Please Help

So I picked up a 2004 XR250R from a friend this last weekend. It had been sitting for at least 1 year if not more. He did not drain the gas out of the carb and the last time it ran before he parked it.

SO when I picked up the bike I changed the oil, changed the spark plug to an iridium one, changed the air filter to a uni, drilled the baffle, pulled the snorkel, and completely took apart the entire carb.

The o-rings seemed to be in pretty good condition so I reused them and I changed the jetting to 48/140. I put the carb all back together but since I was working by headlamp due to no light in the garage. I put the float upside down. So after trying to start it for a while I figured out that there was no fuel in the carb.

So I pulled the float bowl and flipped the float to the correct position and set the screw to 1.75 and also tried 2.5 turns out. The manual said 1.75 was stock but when I pulled the carb it was 2.5 turns out so I tried both. I put the bowl back on, turned the fuel on, put the choke all the way on and spent all last night trying to get it to start. I got one small backfire and nothing else. I tried bump starting it several times with no luck. I checked the spark plug and it seemed a little wet but was sparking.

I don't know what could be wrong. There seems to be plenty of compression since the bike only has maybe 150 miles on it. The only thing that I can think of is that when I put the float in upside down I messed something up or my jetting is way off. I still plan to grind the header but did not make it to it due to it being dark.

PLEASE help I am supposed to go riding this weekend, and I don't want to have to sit there while the wife does all the riding. If you think it is the float level how do I fix it the repair manual shows a float height measuring tool that I don't have.

I forgot to mention I am at about 1000 feet in California

i can't remember what the jetting is supposed to be, but that sounds really rich. i know it's one size up on the main and some do one up on the pilot, that seems like it's a bit more then that, but i could be wrong.

the stock jetting that I pulled was 132/45

Any suggestions as to what the problem is?:confused: The jetting sounded like it should be right

It sounds like your main and or pilot jets could be clogged. Take your bowl off, unscrew your jets and blow them out with air. Then try it.:confused:

did you try starting it before you made all the modifications? When you do mods you should do them one at a time. That way if something does go wrong it makes it a lot easier to diagnose what's wrong. Check your carb again to make sure everything went back together right. Check your fuel line and petcock on the tank to make sure they aren't plugged. If its been sitting a year, it wouldnt hurt to put some carb cleaner in the tank when u get it running and run that through. Make sure your oil filter was oiled with the UNI oil and that it's not too wet. If none of this is working, you can check your valves to make sure they arent way off.


You did dump all the old gas in the tank didn't you, and refill with fresh?

Did the bike sit inside or outside?

Check the electrical system ground points on the frame for corrosion and tightness.

Check the kill switch and make sure it's contacts are not corroded.

Be sure you're using the correct starting drill. Must kick from top dead center. Use full choke and no throttle.

Make sure you're using the choke lever correctly. All the way up is full choke and all the way down is off.

If the idle is set too low it will be hard to start cold too, so try turning up the idle half a turn.

Well i finally figured out what the problem was last night. After changing the jets back and forth and making sure that everything was clean I decided to check the spark plug again even though me and the wife saw it spark before I installed it the other day. Now there was no spark. weird. So I grabbed a new spark plug and it fired right up.:confused:

Thank you for all the replies:applause:

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