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!!PLEASE HELP URGENT!! 2005 crf250x

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Hi I've just rebuilt my 05 crf250x and can't get it started, found a broken earth wire attached to the frame next to the rectifier, not sure where it goes, looked at the diagram, but no luck. Please help.

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It goes under the rectifier actually. They use the same bolt hole.

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OK so I connected the green wire but still no luck starting, not sure why it won't start. Plug is clean, so is air filter, fresh 98 fuel.......

 

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1 hour ago, Matt Titheradge said:

OK so I connected the green wire but still no luck starting, not sure why it won't start. Plug is clean, so is air filter, fresh 98 fuel.......

 

So looking at the photo it doesnt show a broken wire, just a green wire that is connected under the rectifier. Is this the same green wire thats broken possibly just beyond the edge of the photo?

Also what type of rebuild did you do? Did it start and run before the rebuild?

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20 hours ago, TDW said:

So looking at the photo it doesnt show a broken wire, just a green wire that is connected under the rectifier. Is this the same green wire thats broken possibly just beyond the edge of the photo?

Also what type of rebuild did you do? Did it start and run before the rebuild?

I put in a new crank, bearings, new seals and piston+ rings, bike was in storage before I pulled it down. Had a broken kickstart lever and it never really started with the e start button from new. Has new kickstart on it now. 

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The additional details help some and bring to mind a few more comments and questions, even without knowing how long it sat in storage the carb could be a problem if it is contaminated at this point with bad gas or if it is plugged or restricted inside.

Also does it have spark? What about the valve clearances? The green wire??

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I checked the carb bowl and was clean. Has spark. Connected green earth wire back to loom. Haven't checked thevalve clearances thou, need to get feeler guages, bike used to be hard to start before storage, and used to splutter and die, exhaust header was glowing within a minute the last 5 times I had it running. 

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Sounds like checking the valves is needed, usually during a rebuild the cyl head/valves are serviced. Here is a good link with pics about how to check and adjust valves that may come in handy.

 

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Starting is all about compression, fuel, and spark; and the X has some issues that complicate that simple description. The bike has an auto compression release that lowers compression pressure for easier starting, spec for a good engine is 59psi. Add in one or both of the following and there won't be enough compression to start:
Valves are notorious for losing clearance, and when at zero they leak which further reduces compression.
High hour engines can have a worn timing chain that retards cam timing, result is later closing of the intake valves and less compression.

And new rings that are not seated also leak. R cams have later intake valve closing which also reduces compression.

The red header pipe during warmup is a symptom of no load fast engine speed. The cause is high manifold vacuum causes low compression pressure which causes the mixture to burn so slow  that the exhaust gas is still burning in the header. The fix is to use a lower warmup speed.

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checked valve clearances today and the Intake LH  is .013, RH .001.

Exhaust LH  .013 RH .012 

 forgive me if I'm wrong.. Does  the LH intake valve needs a shim of .008 ? And both the exhaust shims  .001 and .002 ?

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Both of the intake valve clearances are way off, the spec is .004 - .006, so the LS needs a larger shim, and RS needs a smaller shim.

The exh valve clearance spec is .010 - .012, so your close there.

You might need to get the intake valves replaced depending on what size shims are in there now. Did you check clearances or re shim the valves when the other engine work was done recently?

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Hard to say if it will fire up or not but the int valve with .001 could actually have even less and that will cause it to not start. Its one of the main reasons that older bikes dont want to start. Also whoever left the LS int clearance at .013, I dont know what to say other than thats bad, hope you didnt pay somebody for that.

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Mine was getting harder to start during a three day trip.  I could never get it started with the starter, always had to kick it.  After the trip it wouldn't start at all no matter how much I kicked and recharged the battery.  Confirmed it had fuel and spark.  Next I checked the valves and found them out (I don't remember how much out).  Got them back into spec and it started up immediately and runs like a champ now.

 

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 sweet, I swapped my two intake shims around and got one into spec, tried to start and it popped but didn't start. One intake valve I still can't get the smallest (.015) feeler guage in to check. So I'm waiting for a shim kit from eBay, after I re-shim it should be ready to go. 

Many thanks for the advice.

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On 8/15/2017 at 11:09 PM, Matt Titheradge said:

I checked the carb bowl and was clean. Has spark. Connected green earth wire back to loom. Haven't checked thevalve clearances thou, need to get feeler guages, bike used to be hard to start before storage, and used to splutter and die, exhaust header was glowing within a minute the last 5 times I had it running. 

Hey Matt - just because the bowl was clean doesn't mean that the jets are clean. I'd remove the carb and do a full service on it to check each and every port and jet to make sure you're perfect and ready to go once your shims show up!

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