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runs then dies

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My 2006 bone stock crf250x runs perfect for 5 minutes, then dies like it's out of gas.

It won't start for about 30 min, then repeats cycle.

It just started doing this after the winter.  I even changed the gas and ran it a couple of times.

I figure it's something with the float.

 

What's the general "how to" to go about repairing this?

What may I expect to pay someone to fix it?

TomJV

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Sounds like your float bowl is just running out of gas and then 30 minutes later its full enough to run again. Pull off your gas line from the carb and check that it has flow. Then if that doesn't work take your carb off and give it a good cleaning. Make sure your float moves freely. Getting the carb in and out is the hardest part of the whole job. Good luck. 

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 Check the vent on the top of the gas cap.  Also the vent lines from the carb.  Make sure their not plugged.

 

 And as was mentioned, check the fuel flow from the tank at the carb.  If it's little, then you'll need to clean the filter screen in the tank.

 

Jim.

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Holy crap!

I removed the fuel line from the carb and "low and behold" there's no gas coming from it!

I put it on "run" (or whatever it says) and it's just dripping.

I put it on reserve and it runs great.  Took it apart and there's not much to see other than the screen looks a bit caved it.  I ordered a new one.

 

Next, I'm gonna gut the air box and drill the baffle like Rick Ramsey did.

I ordered a #42 slow jet, a #135 main and I'll prolly drop the clip one notch.

 

What are the rest of you guys doing?

TomJV

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So you found the problem....good deal.

 

On your jet's the #135 main is too small.    I'm at sea level and run a #158 with a JD red needle.  That's with stock exhaust (I like my bikes quiet) and the air box top open.  Nothing else done.

 

Check the FAQ thread at the start of the forum.   You'll find a link to the Jetting thread.  Try and find someone who rides at the same temp/altitude and has a setup similar to what you plan to do.

 

Jim.

Edited by Jim Dettman

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+1 on the previous post.

I'm at sea level and also run a 158 main and JD needle, and same mods.

 

Just research the info in the sticky and at Rick Ramsey's site.

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Thanks for the info guys!  I DID read Rick's page, but must have got it wrong somehow.

 

K, this is Ricks 250X chart(stock).

 

 

999 ft
to
Sea Level

Screw
Clip
Main

2 1/2
4
135

2 1/2
4
135

2 1/2
4
132

2 1/4
3
132

2 1/4
3
130

2 1/4
3
128

2
2
128

 

Then he says add 5 to the main and 2 to the clip for a modded bike.  No brainer right?  LOL

Anyway, that's where I got the numbers from.

 

TomJV

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Whoops!  It didn't like that when I pasted it!

Sorry, buy you get the idea . . .

TomJV

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My proposed 2004, 2005, and 2006 (but NOT 2007, 2008, and newer) 250X jetting chart for a 49-state 250X (not CA model) with stock intake and exhaust (stock settings are shown in yellow):
(screw = fuel screw, aka pilot screw; clip = needle clip position, numbered 1 to 7 from the top position; main = main jet)

 

(I'm having trouble with the chart, but it says 130 on the main)

 

The pilot jet is a 42 (larger than stock 40) and the needle is an NCVT (stock) for all altitudes and temperatures.
The intake and exhaust are assumed to be unmodified.

If you have a somewhat opened up intake and exhaust, add 5 to the main jet size and add 2 to the clip position (for the settings for your altitude and temperature in the chart).

 

 

Anyway, so I need to find out what a good number is for, say sealevel to about 2000 feet for a main jet.  #165?  I'll keep reading.

 

TomJV

Edited by tomjv

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I just want to repeat Jim's recommendation to check the gas cap vent hose. I had the exact problem on another bike and a clogged vent hose ("trick" aftermarket billet vent hose) was allowing vacuum to be created in the tank. It would run fine for a while, then simply die as fuel could not flow as vacuum built. Just pull your vent hose off, or take off your gas cap and check for flow.

Good luck!

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I, so I wised up and ordered the JD kit.  I sounds easy to just order a bunch of jets and just do it.  When you call parts guys, they don't HAVE them!  I mean yes, they have jets, but they don't have say 165 for a 250x.  "I have 130, 133 and 160 . . . ".  I got tired of fussing with it.

 

I raised (lowered?) the subframe and removed my airbox.  Pretty easy procedure once you find the rubber tab on the bottom that allows you to pull the boot off the carb LOL!  Anyway, I used a Weller Solder gun to cut the box.  It walked thru it in no time and left pretty clean edges too.  I was temped to make some holes behind the black cover on the right side too.

That Weller is a great tool to have around.  Good for soldering too!

 

I drilled a couple of holes in the baffle too.  Nothing crazy, just a couple of wee holes.

 

What's the best way to clean this filthy mess of an airbox?  I use NoTol, so I was gonna fill a bucket with dishwasher soap and hot water and soak it then sponge or powerwash it out.  The would-be cleanest part of the bike is the dirtiest!

 

How much trouble is it to remove the carb while I'm here?

 

Thanks again guys!

TomJV

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Dish soap will work OK.

 

As for the carb, it's tight in there.   Remove the upper shock mount so you can push it off to the side, which gets the carb out easier (some take out the whole shock, but you really don't have to if you have a little patience).

 

Jim.

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I personally like removing the shock. Every time I have tried doing it with the shock cost me more time.

Remove the fuel tank, seat, side panels, exhaust, then the shock. After removing the bolts on the shock just lift up on the tire and the bolts pull right out. The shock is so easy to remove it shocked me the first time.

After you remove the shock lift the subframe up after loosening your carb boot to the air filter. Now you have an easy clear access to the carb.

I can remove all that in 15m tops.

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K, I did the JD kit yesterday.  Cake!

I lowered the subframe(or rather clam-shelled the rear fender), removed the airbox and removed the top shock bolt.

Then I was able to rotate the carb just enough to get to the top and bottom. Oh, I also removed the top cylinder head mount bolts.

 

All-in-all, it's pretty easy.  You definitely have to take your time.  You definitely need some tools.

Luckily, I happened to have these: Crafstman Socket Cap Set.  If you don't have them, I recommend you p/u a set.  Great tool!

I don't know how I would have gotten the main jet out without it.  I threw a #160 in there(modded air box and drilled baffle, 0-3000', summer)

and a #42 pilot.  It's my guess this bike is gonna start way easy now.  Gonna do the #42 in my R next.

 

On the needle, I used a magnet with a 1/4" extension to get the allen nut out.

Then, I used a long dissecting tweezer to get the spring and needle.  I used the red needle.

 

As for the AP mod, I lucked out!  It was already done.  Whew!  I would definitely have removed the rear shock to do it though.

I got this bike like brand new!  Still had the nubs on the tires.  The previous owner had a kuba link installed and still was afraid to ride it. 

'Couldn't get 2 feet on the ground.  The bike sat and got gummed up.  He had someone clean the carb out and they must have done the AP.

 

While I was there, I did the smog mods too.  Can't wait to get it back together and ride her.

TomJV

(well, I had a pic of the socket cap set, but the forum won't let me use photobucket.  Can't find any help . . . )

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Got the bike back together and it's great!   Did a valve inspection while I was there.  All good at 65 hours.

It started in 1 sec!  I ran it for a while and was doing wheelies in 3rd gear.  The bike feels the same, but is way more peppy.

The exhaust is not noticeably louder than stock.

The question is, do I need to jet-test it or not? 

TomJV

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Did you remove the air filter metal screen?   If so, then your pretty close to spot on with a 160.   If not, your a tad rich with the #160, which is not a terrible thing.

 

Depending on how much time you have on your hands, you might want to try a 158.  The main jet can be changed through the bottom by rotating the carb.  You do no need to remove it.

 

Jim.

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Yes Jim,

I took the screen off.  Honestly, I don't know what it does anyway.  I was presently surprised to fine out how easy it came off.  -Just four tabs and it popped off.  Also, I can always put it back on if I want. 

TomJV

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I finally got around to uploading a pic of my airbox being cut with the Weller Solder gun.

After I did the cut, I soaked it in a bucket with hot water and powdered dishwasher soap.  With a little help it came out pretty clean.

IMG_5892_zpsb6f5f689.jpg

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