too lean

3 replies to this topic
  • xr600rdr

Posted May 27, 2005 - 06:05 AM


My 86 xr600 is running way too lean. When I get it dialed in, I can ride for a day or two before it needs adjustment. It's stock except for pipe/jetting which was performed by the local honda shop. Anyone know if I can convert the old beast to a single carb?

  • Mantrasonica

Posted May 27, 2005 - 06:43 AM


You have to adjust the mixture screw every couple of days? Need to make sure those carbs are spotlessly clean. Inspect the mixture screw carefully. People have a tendency to crank it closed too tight and it distorts the face of the screw. If your mixture screw has a ring around it replace it.

Is your airbox hacked? When I bought my '87 someone had drilled the crap out of the airbox. Although many here will tell you to open it up, my bike runs much better with the stock airbox.

I'm running 125 main (I think) in the primary carb and a 130 in the secondary. I believe I'm running a 45 slow jet. The bike runs really strong. I suspect I'm still slightly lean down low as well, since cold starting can be tough. Everywhere else it runs perfectly.

I imagine you could convert it to a single carb somehow, IMO that would just be opening another can of worms.


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  • xr600rdr

Posted May 28, 2005 - 07:30 AM


Thanks for the advice. The airbox is opened up along the top... maybe I'll hit the salvage yard to see if they have a replacement. I'll also pull the air mixture screw out and see what it looks like. I've heard that the dual carbs have always been tempermental, that's why I thought about converting. When I first got the bike, it had no top end, past half throttle, it was dead. It ended up having too big of jets in. I think there is a 120 and a 118 in there now. This thing won't even idle though, it sets way too high and stays there. I spend 10 minutes getting it started and another 10 getting it dialed in when I want to ride. I only use the air adjustment (choke side of the main carb)... is there a secondary fuel adjustment on that set up as well?

  • zx7rye

Posted May 28, 2005 - 03:44 PM


If your idle is hanging, you're running lean down low. What size slow air jet do you have in the carb?

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