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Problems starting 2007 Honda CRF 250X

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I’m looking for some advice or help from anyone.  I raced in a Hare Scramble for 2 hours last Saturday.  I came home, unloaded the bike and pressure washed it.  From that point, it would not crank.  So far, I have:

 

Drained the bowl

Changed the plug

Cleaned the air filter

Checked the gap on the valves

I know the timing is dead on

Cut the kill switch completely loose

 

I can see that the plug is getting fire with it out of the bike and connected to the coil.  I can also see that the bike is getting gas into the cylinder.  It turns over as if it has good compression.  It will not crank with starter fluid.  I have come to a road block other than buying a new ECU or other electrical parts.

 

Any advice is welcome.

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There are a few things that could be going on and most likely, it's water and/or crud in the carb.  Was your air filter very wet when you cleaned it?   Water in the air box?

 

I would:

 

1. Check the oil level.  Makes sure it's at the proper height.

2. With the gas off, throttle wide open  turn the engine over several times.

3. With the air filter off, throttle wide open, use a *brief* squirt of starting fluid, close the throttle and let it crank over a few times.

 

  You should get a bump out of it, if not running for a second or two.

 

  If you do, then you have water in the tank and/or carb.  Drain the tank and carb completly, then try fresh gas.  If it still won't run, then it's the carb.  The carb passages/holes in the jets are quit small and easily plugged with crud, which water could have easily carried in there.

 

Jim.

Edited by JimDettman

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Jim,

 

Thank you so much for your direction.  The race last weekend was extremely dry and dusty, so during washing the bike, I removed the air filter and installed a block off cap and Simple Green/ pressure washed the inside of my airbox.  After using compressed air to blow the bike dry, I removed the cap and did not see that any water had gotten past the cap.  I installed a new air filter, changed the oil filter and oil, and changed the oil in the transmission.

 

I have now followed your advice. After draining the tank, I tilted up the subframe and removed the shock.  I removed and cleaned the slow jet and idle jet.  I blew compressed air in the main jet and others.  I blew out the carb through every hole/port available.  I still have the same problem and am calling it off for today.

 

Thanks again for your help.

 

Robin

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Check the camshaft timing. It may have jumped a tooth on the camchain. If this is what happened look at the cam chain tensioner.

 

 

 

 

 

 

Mike Mendel

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 I removed the air filter and installed a block off cap and Simple Green/ pressure washed the inside of my airbox.  After using compressed air to blow the bike dry, I removed the cap and did not see that any water had gotten past the cap.  I installed a new air filter, changed the oil filter and oil, and changed the oil in the transmission.

 

I have now followed your advice. After draining the tank, I tilted up the subframe and removed the shock.  I removed and cleaned the slow jet and idle jet.  I blew compressed air in the main jet and others.  I blew out the carb through every hole/port available.  I still have the same problem and am calling it off for today.

 

 Robin,

 

  Well that's certainly the right way to do the washing.  I was assuming you had not and it's not and it's easy to get some water sprayed in with a pressure washer if you not careful.

 

  So before you do anything else, are there any more details you'd like to toss in?

 

  And a couple of questions:

 

1. Did you run the bike before the wash once you got it home or no?

2. Was it running fine up to the point where you loaded it up?

3. Any problems during the race; backfires, died, etc?

4. When you did the test with the starting fluid before you cleaned the carb, did it run for a second or so or no?

5. When you cleaned the bike, did you lay it over on it's side?

6. You change the oil after the wash, correct?

7.  Is the oil level at the correct level now?

 

Jim.

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1.  An hour and a half after the race, I cranked the bike to put it in the back of the truck to get it home, but I did not crank that bike after I got it home.

 

2.  It was running fine until I loaded it up.

 

3. No problems during the race.

 

4.  It has not run at all since I got home from the race.  Not even for a second or two.

 

5.  Yes, I laid it over on its side.

 

6.  Yes, I changed the oil after the wash.

 

7.  Yes, the oil is at the correct level now.

 

I have now taken the head cover back off and rechecked the timing and the valve lash and all is good there.

 

Thanks for your help, and I am open to any suggestions.

 

Robin

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I know your saying you have a spark, but I wondering how strong it is.   Check up underneath by the tank and make sure the ignition coil has a good clean ground to the frame (it's a small wire that comes off the coil).

 

I still think it's fuel related, but you should have gotten *something* out of the starter fluid test.  Starting fluid is extremely volitile and even all but the weakest spark usually gives you something.

 

Have to say I'm scratching my head a bit...it doesn't add up.

 

BTW, I would have suggested replacing that slow jet when you took the carb apart.   They are almost impossible to clean.  

 

Only other thing I would check is make sure all the vents are open (crankcase, carb, etc).  They can plug up with mud, and since you had it on its side, one of them may be filled up and plugged.

 

Jim.

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there are some little spark tester gizmos that you can get that go between your wire and plug with a gap.  The spark has to be a certain strength to jump the gap.  that would help tell you if it is strong enough.  any auto parts store probably has them.  or harbor freight. Cant be much more than around $10.

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