CRF250x Whisperer where art thou?

We just brought home an 05 yesterday that would only run with the choke on. No worries, pull the carb clean it out and remove any of the carb cheese that had collected while it set since August.

Put it all back together and no start.

I did notice that I had connected the throttle cables backwards at the tube. Will be checking on the big three (air, spark, fuel) and was wondering if the throttle position sensor location could be causing me an issue or if there are any other things to look for?

Start with the basics first.   Don't touch the TPS.   If you mess with it, it will need to be recalibrated and it being off won't keep it from starting.  You can run the motor fine with it un-plugged.


Since you just messed with the carb, that's the obvious thing to look at first.   Also, on an '05, I would replace the fuel line and check for good fuel out of the tank (the mesh screen in the tank may be plugged).



You may have to rechecking cleaning on the pilot jet or possibly replace it.  What looks clean, sometimes isn't.  

Yeah, this thing was jetted way lean with a 128 main. It was titled in Utah. So that makes some sense. JD Jetting kit is inbound. Also the floating valve plate on the throttle slide in the carb had a jacked up rubber gasket.

We would also like to find a black plastics kit for this and have only found the factory red. Is there a source for the black? I have seen many that have had black plastics and am looking for these.

We would also like to find a black plastics kit for this and have only found the factory red. Is there a source for the black? I have seen many that have had black plastics and am looking for these.

Someone needs to become skilled in the ways of Ebay.


As with any used bike, let ways of the bay be your guide.

TPS won't cause a bike to fire. A lot if riders unplug it.

Ok got it re-jetted and it fired right up and runs like a monster. Installed a 42 pilot and 158 main per the instructions in the JD kit. We also installed the RD flexible fuel screw. Now it won't start unless I blow into the vent hose on the tank. Then it won't stay running.

The other issue is the tail light will not come on. It is a brand new light and there does not seem to be getting any juice from the relay by the air box.

Running is the most important because when it runs it really rips.

So after reading a ton of info on here I checked the gray wire from the CDI and sure enough there is no ground coming from it while the bike is running.  That solves that mystery.  Now when the bike gets warm it wants to die and then not start again.

You'll want to check the valve clearences.




That is what I was preparing myself for. I am fortunate that I still have that stuff from my previous X of the same vintage. Next will be to re-wire the tail light to an ignition on power and ground to do away with the CDI thing and relay.

Checked valves and they were in spec. Noticed when taking the tank off the fuel line from the petcock to the carb was really loose. It seems the little spring clamp had given up the ghost. I had some better clamps and replaced it. Bike fired right up and I rode it around for about half an hour. Then let it sit running while I fiddled with the idle and air/fuel screw to dial things in. I let it get hot enough sitting that it was sending coolant to the tank. Killed it and let it sit. Then it fired right up.

I am guessing it may have been sucking air bubbles through the loose connection.

Next stop graphics...

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