650r jetting

On my 2003 xr 650r I'm running a 165 main and a 68s pilot with the stock needle in the 3rd position, bike is fully uncorked with a white brothers E2 slip-on. The bike starts on the first couple kicks with no choke and a low adjustment on the idle screw, the fuel screw is at 2 turns out. But when I give it gas it boggs down and dark smoke comes from the exhaust. I have main jets from 165-175 and the problem has gotten better the lower I've gone. I still have the stock backfire screen in if that helps, any help would be appreciated.

On my 2003 xr 650r I'm running a 165 main and a 68s pilot with the stock needle in the 3rd position, bike is fully uncorked with a white brothers E2 slip-on. The bike starts on the first couple kicks with no choke and a low adjustment on the idle screw, the fuel screw is at 2 turns out. But when I give it gas it boggs down and dark smoke comes from the exhaust. I have main jets from 165-175 and the problem has gotten better the lower I've gone. I still have the stock backfire screen in if that helps, any help would be appreciated.

what elevation?

sea level

It sounds to me like your running to rich, but I wouldnt think the 165 shouldnt be to rich for you setup. How well does your pipe flow? Are you using the stock filter? I would try running it without the backfire screen and filter, just for a minute and see if that makes a difference. You may want to think about an UNI filter.

I'm at about 1000' and I run a 172 and and 68s with a UNI filter and stock tip completely opened up. I get just a small bit of hesitation sometimes with the 175 main.

put in a 170 main with no backfire screen and it sounded better at idle than the 165 did, the hesitation isn't as bad, just mainly at full throttle now. maybe a 168 will do, but that's it for today it's 100 degrees and I'm tired.

But when I give it gas it boggs down and dark smoke comes from the exhaust.

Sounds like your choke is still on. On a properly running XR650R, if you turn the choke on after it is fully warmed up, it will bog and will shoot black smoke from the exhaust.

Double check the choke mechanism and remember, lever up is choke on. :prof:

Sean :cool:

choke was on, got ride of the smoke, but still not jetted right I snapped my carb needle in half trying to change the clip position. I'm hopeless.

choke was on, got ride of the smoke, but still not jetted right I snapped my carb needle in half trying to change the clip position. I'm hopeless.

Just change your name to Charlie Brown! :banghead:

What needle was in it? The number should be at the top just below where the clips go.

Sean :cool:

If you still have your stock needle put it in at the fourth clip position (experiment with it). The choke was your problem all along. At sea level you should be able to use your 170 or 172 jets with no trouble at all.

Next thing you need to watch for is the float level. The stock float level is only good for riding flat. If it starts dying right after climbing a hill and floods set the float so it shuts off the fuel 2mm sooner. Don't mess with it until you know if it is going to be a problem.

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