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pops but wont start

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Hey everyone, I just replaced valves and top end in my 05 crf and I cannot get her started. If I kick her like five times I will get a pop out of my exhaust. I installed a head from an 06, brand new. Also, the valve clearence is in spec. The bike sat for about a year and then I did the work. I cleaned the carb before I put everything back together, but it may be at fault. In the process of cleaning the carb I took out the air screw and noticed the o-ring was shredded. I went to the local hardware store and found what seems to be a temporary replacement and installed it. So when I put everything back together it just pops every once in a while. Can anyone point me in the right direction so that I don't have to pull EVERYTHING back apart. I took my time replacing everything and I am no stranger to rebuilding engines but this has me second guessing everything I did. I did all of the work in my college house basement and I did it over a couple of weeks. Anyway....sorry to rant. Could the problems be carb related or maybe (gasp...) I installed a ring improperly? I am 99.9% sure that I installed the rings right and I just checked the clearence again so I know that that is not the problem.

ANY help is greatly appreciated as I am trying to ride this weekend and I haven't ridden in over 6 months and its killing me.

Thanks,

Jon

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Jon,

Look at the carb slide. If you installed the removable plate upside down the bike will do that. You have to tow it to get it to light and then it'll backfire like hell.

The shape of the slide bottom and the shape of the part when installed correctly match. So inspect the slide bottom.

Somewhere in the manual there is a shot of looking through or at the carb so you can see the right way.

Hope that does it if not you one thing to cross off the list.

SM:ride:

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I would put money on the timing being a tooth off, its easy to do. I would pull the valve cover off and pull the spark plug out, I use a real long screw driver to drop in the sparkplug hole to find TDC, then check your timing marks.

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I will recheck the timing. It sure sounds like its a timing thing. But I thought it would be pretty hard to mess up the timing with all of the marks and whatnot. I will recheck it and let you know. Thanks for the help guys i will keep you posted.

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OK guys, so I can start it but only if I have the throttle open. I have to hold the throttle open and it will start, I then adjusted my idle and it stayed running. Once I took the choke off the bike died. It has only been running for about a minute. So I guess I can say it is a carb issue. I cleaned all of the jets. What do you guys think? Do I still have a carb issue or (i know this sounds silly) is my throttle cables out of adjustment? Is there a carb passage that I am overlooking? The backward plate thing: would I have taken it off if I only cleaned the jets in the bowl? Also, I took off the AP cover and the metal in the diaphram was rusty and there was water in the cover.

Any more help is greatly appreciated!! At least I got it started!

Thanks again,

Jon

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The pilot is clean, maybe the corresponding passage isnt though. The bike was still cold when I shut off the choke, so that is probably why it died. I always have to hold the throttle open to start it so that would indicate the pilot circuit right? Shoulld I pull the carb again and reclean it? Or can I spin the carb in the boot and access everything from the float bowl? Thanks for the help AgentSmith.

Jon

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You can spin the carb in the boot and you will be able to access what you need. I just did this about a month ago and the only hard part is getting the jets back in! I would still check your timing though. More times than not in this forum after a rebuild and the bike wont start or stay running it is because the timing is off.

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the o ring will need to be replaced with the factory o ring because it needs to be made of neoprene it'a synthetic rubber and highy resistant to oil/ heat & gas.gas will destroy a standard rubber o ring. but i would bet the timing is off

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