Uncorked XR650R Has Back Fire issues and dies

Put some serious trail miles on this weekend up in the Bunyan Forest. Had a great time but the xr had some little glithes. My first ride since uncorking it. Have a 68s piolet, 175 main, different intake boot, pulled the crap out of the air box, and running a UNI filter. Bike hauls the mail but (sometimes) on decel the bike pops and dies instantly. By the end of the weekend I could pull the clutch and keep it running, but I know it can be fixed. Anybody have any suggestions? :cry:

P.S. This weekend made me a believer...I use to scramble a 2 smoker..but the xr is way better suited for my type of riding. The smooth power it produces is just amazing. I can't wait to do it again. :cry:

Have you changed the needle itself and/or altered the clip position?

Yes, I purchaced the recommended needle and have the clip in the third from the top. :cry:

What about the muffler? Did you replace with HRC insert or drill out the plug?

Put some serious trail miles on this weekend up in the Bunyan Forest. Had a great time but the xr had some little glithes. My first ride since uncorking it. Have a 68s piolet, 175 main, different intake boot, pulled the crap out of the air box, and running a UNI filter. Bike hauls the mail but (sometimes) on decel the bike pops and dies instantly. By the end of the weekend I could pull the clutch and keep it running, but I know it can be fixed. Anybody have any suggestions? :cry:

P.S. This weekend made me a believer...I use to scramble a 2 smoker..but the xr is way better suited for my type of riding. The smooth power it produces is just amazing. I can't wait to do it again. :cry:

Is it hard to start after doing this? If so it sounds like a flooding issue. You may need to jet down from the 175 or it could be the float level is too high allowing too much fuel in which would usually show up right after climbing or decending a hill. If you see any fuel flowing out the overflow after climbing or decending or any other time, adjust the float.

Sounds too lean. Careful that you dont burn a whole through the piston. When I had mine too lean she ran like crazy, then would just die. Hard to start it back up. Severe backfires on deceleration. I have mine a little rich right now. I do not have to choke it at all to start. She just fires right up. I don't have any fowling that I can tell either. But since I uncorked her and addedthe big gun my gas milage has gone to crap. With that little tank it's hard to make it to and from work on one tank.

Yes, I drilled out the stock muffler. It seems to happen most when I'm in 1st or 2nd gear right after I excellerate pretty hard and let off..It idles down just a bit and then.........pop. Does that sound like jetting or float level? Thanks for the help guys...I couldn't wait to get home and ask. :cry:

Yes, I drilled out the stock muffler. It seems to happen most when I'm in 1st or 2nd gear right after I excellerate pretty hard and let off..It idles down just a bit and then.........pop. Does that sound like jetting or float level? Thanks for the help guys...I couldn't wait to get home and ask. :cry:

Nukboy may be right, once when I installed a 68s slow jet I had a little bit of gummy glue like substance on my finger. It got into the holes on the slow jet and acted up kinda like your describing.

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