[anthony85]

Hi. I’m new here to the forum. I just purchased a 2006 crf 250x. It had sat for 6 years before I bought it. I did the normal things; cleaned the gas tank, changed the batter, new air filter, and I just pulled the carb and gave it a proper cleaning. The carb was in pretty bad shape but after three cans of carb cleaner and soaking all the jets it was sparkling inside. I put the bike back together and it won’t fire up. The bike is “cycling” when I press the ignition but it will not fire. I forgot to mention I changed the spark plug too. Does anyone have any suggestions or had a similar experience. Thanks guys. I’m looking forward to getting this bike off the stand and in some dirt.

My editing is off but I also did not mention the bike is in neutral, I have the clutch in, and the choke is on. I know I am getting gas to the carb because I forgot to tighten the bottom carb inspection cover and I had a small leak. I tightened the inspection cover and no more leak.

Tony

[dencof]

I recently bought an 06 250x, my first Unicam motor, and it was very hard to start. It turned out to need a valve adjustment, and it was the last one it could have before replacing the valves. This appears to be a common issue with these bikes; you'll read more on this when you look around on this great website.

[JimDirt]

Welcome to the site !!

dencof is correct , check your valve lash , and make sure its within spec (do you have a manual ??) , also it would be nice to know your starting procedure , these bike like a little fuel when you start them cold , what i would try is , twist the throttle about 6 times (full quick twists to get gas into the carb , as they have a accelerator pump and it needs to be primed when cold), pull the choke , and hit the button and see what happens , it should either pop or start right up

Report back with findings

[Leardriver]

The carb could still be plugged in places that polite people don't talk about. Sitting can be a nightmare for carbs.

In the bottom of the float bowl, there are fuel passages for the accelerator pump. There is a tiny check ball and spring that get gummed up, and that is an intake orifice from the fuel in the float bowl to the passage that squirts in the raw fuel in the accel pump. You can tap out those parts gently, and clean them.

The way to test the accelerator pump system is to twist the throttle and look for a raw fuel squirt into the carb. I can see it with a dental mirror and the air filter off, but many have to tilt up the subframe and take the back boot off of the carb.

Next, off to the pilot circuit. Remove the pilot jet, the fuel screw, spring, washer, and o ring. Blow out the top of those passages, squirt a little carb cleaner in there, and gently scratch up there with a metal dental pick. There are chunks and deposits of ethanol pudding that love to accumulate there. Shoot a blast of air from an air compressor blower nozzle in those holes until you can feel or hear air coming into the carb bowl. I would replace the pilot jet, no matter how clean it seems. I paid $10 shipped for 12 of them ordered from China.

This is a project. The spots I mentioned are the ones that are hiding from a standard carb cleaning.

[anthony85]

Wow. Thank you guys. My starting procedure is to give the throttle two full twists. I’ve always been hesitant to intro more fuel into the carb for fear of flooding. I pulled off the carb again to give it another cleaning but I will try introducing more fuel if it doesn’t start up when I get the carb back on.

Before I pulled the carb a second time I put fuel straight into the spark plug. The bike fired right up but only stayed on with the fuel in the spark plug hole. The bike shut off once the fuel had been fired. So that kinda confirmed I still had a clog in the carb somewhere.

I have the carb off still and what I will try is hooking back up to my fuel tank without putting it back onto the bike. I’ll introduce fuel to bowl and give the throttle mechanism a couple twists to see if fuel is moving how it should. I won’t have it back together until this weekend but when I do I will let you know.

I plan on cleaning all the jets, little holes, the float jet, and passages. Thanks guys.

[anthony85]

This will be delayed another week. The float bowl pin deteriorated and I had to order a new one. I’ll keep everyone updated.

I’ve cleaned the carb and jets several times and it is looking a lot better. I’m just going to keep at it until my new pin arrives next Friday.

In the mean time the rims are at the shop getting new tires and tubes.

[anthony85]

Okay. So after not having anytime to get this thing going I finally got the carb cleaned and fuel moving through it. I put it back on the bike and sure as . it started right up! But now I have a leak out of the accelerator pump. The diaphragm is brand new and both the o rings in there are brand new as well. Any suggestions? Is there a “leak valve” that can be adjusted? I’m reaching my wits end on this carb.

[JimDirt]

If the AP is leaking it can only be the diaphragm or the O-Ring or the D-Ring (part 14-15 in lower left picture) make sure they are installed correctly and did not get pinched during installation , if any one of them got pinched , you will need to replace it/them