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XR400 won't start


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Hi all,

My XR400 is not starting. It sat with gas in the float bowl for about 3 years. I have taken the carb out and cleaned it as much as I could (removed and cleaned the jets and the internal passages that the jets lead to as well as the float needle.) It is getting spark, but I don't have the socket to pull the plug. It did run well before it sat and before I pulled the carb it would sputter a little but now there's nothing. I even tried using starting fluid in the airbox and it still didn't start. When I kick it over and give it gas the air coming out of the exhaust doesn't smell like fresh gas, it smells more like the varnish that was in the float bowl when I drained it (although it did smell like starting fluid after I sprayed the airbox.) I am totally dumbfounded why even the starting fluid isn't working. Any ideas would be very much welcome!

Thanks!!

Sam

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That's what I thought. The compression feels pretty good when I kick it over. Also the gas flows through to the carb so the fuel filter seems fine. I just don't get why I don't smell fresh gas in the exhaust. Even when twist the throttle over and over to try and flood it just to test the fuel delivery I don't smell anything but old varnish. Is there anyway to test the plug without pulling it?

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I didn't submerge the carb in cleaner, I just sprayed it and made sure that the jets and their passages were clear. I cleaned off all the visible varnish with a toothbrush. Anybody know where I can find a good schematic of the carb? I might have missed a port or something that wasn't obvious. I'm going to buy a service manual, but until then a good diagram would be helpful.

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vacuum that's why you cant snap open the throttle on these older bikes, they bog/fall on their face

that's also why you do not try to start it by holding the throttle wide open, unless it was tipped over and flooded, this works for both types of carbs, standard and accelerator pumps, if you tip over hold the throttle wide open, and cycle the engine a few kicks, that clears out all the fuel, then let go of the throttle and give a good kick, works every time

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Well, I think I'm gonna have to pull the carb again when I get home tonight and make sure I really cleaned everything as well as I thought. It was pretty dark by the time I finished up last night so I might have missed something. Thanks for your input MegaDeTH - you and this site are a great help to us newbies! Cheers!

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