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Idle problems on my XR650R


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I've adjusted the idle back and forth and my problem is when I let off the throttle the idle stays high. If I blip the throttle it will come down, sometimes it won't unless I blip it 3 or 4 times. When in tight technical terrain it's a [@#$%&*!] because the RPM's stay high and I've been having some overheating problems. Any ideas on this one? ?

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when I let off the throttle the idle stays high. If I blip the throttle it will come down,

You've got a lean spot. It could be an air leak between the carb & cylinder. Make sure your intake is clamped down properly and that it's not damaged/cracked. Make sure you're not running too small of a pilot jet.

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If the throttle itself isn't binding then it sounds like it could be a lean condition. Did you replace the stock pilot jet with a 68s? I actually ran a 70s pilot jet with my mods until I bought the Edelbrock.

I replaced the 68S with a 68. Think I should go up to a 70?

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when I let off the throttle the idle stays high. If I blip the throttle it will come down,

You've got a lean spot. It could be an air leak between the carb & cylinder. Make sure your intake is clamped down properly and that it's not damaged/cracked. Make sure you're not running too small of a pilot jet.

I'll check for a air leak. Don't think I have one though. I'm thinking it's probably to small a pilot jet. What is the usual setting for sea level riding for a XR650R? Uncorked with FMF Ti-4 pipe and FMF powerbomb headers.

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Some bikes in the same conditions seem to like different settings. My understanding is that a 68s is better then a 68. My bike ran well at sea level with the 68s but when I opened up the side panel the 70s made it run like it should. Try richening the pilot screw. My bike definately ran leaner when I installed the header. I actually was very pleased with my stock carb when I had it dialed in but I couldn't pass up the extra power by running the Edelbrock. With your set up you may want to try the 68s, 180-185 main, and run the bike. If it still pops on deceleration richen the pilot screw in 1/4 turn increments to see if it stops. Thats how I did it. When I installed the 70s the popping was gone altogether.

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Some bikes in the same conditions seem to like different settings. My understanding is that a 68s is better then a 68. My bike ran well at sea level with the 68s but when I opened up the side panel the 70s made it run like it should. Try richening the pilot screw. My bike definately ran leaner when I installed the header. I actually was very pleased with my stock carb when I had it dialed in but I couldn't pass up the extra power by running the Edelbrock. With your set up you may want to try the 68s, 180-185 main, and run the bike. If it still pops on deceleration richen the pilot screw in 1/4 turn increments to see if it stops. Thats how I did it. When I installed the 70s the popping was gone altogether.

O.K. So I'm a little confused here. You said to try the 68S but then you said to try the 70 also. I get a distinct popping noise upon decel also sometimes. I think I'll just go get a 70 and a a 180 and a 185 main and fiddle around with them to see what works best.

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Sorry. I didn't mean to confuse you. For clarification, I did not run the 70s until I opened up the side panel. With your setup I believe the 68s and tuning the pilot screw will eliminate the popping on decel.

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If the cable isn't dragging, if the throttle free play is set right, and if the carb piston and linkage is not hanging, then the bike is too lean on the pilot or it's got an air leak. Sounds more like it's too lean on the pilot jet though, since you mentioned that it overheats at low speeds. Good luck with it!

L.L.

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Do yourself a big favor and junk the stock carb. I fought with the hanging idle porblem for a while and tried several things to correct it, none of which seemed to work. Get yourself a Edelbrock carb they are great! More power, better bottom end, 1st kick starting 90% of the time hot or cold and no flooding ?

:devil:

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Do yourself a big favor and junk the stock carb. I fought with the hanging idle porblem for a while and tried several things to correct it, none of which seemed to work. Get yourself a Edelbrock carb they are great! More power, better bottom end, 1st kick starting 90% of the time hot or cold and no flooding :devil:

?

How much does a edelbrock carb run?

I also think I'm going to try the 70 pilot jet first and if that doesn't resolve the problem then that carb is history

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Try the 70s pilot jet first. The Edelbrock pumper carb retails for ~$485, but Rob Barnum of Barnums Pro Products sells them for about ~$400. I've got them on several bikes and they perform very well. Rob Barnum did the R&D on this product for Edelbrock and uses it in all the bikes he races. You can either call or email him at sales@barnumspro.com or (760) 868-8097

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Do yourself a big favor and junk the stock carb. I fought with the hanging idle porblem for a while and tried several things to correct it, none of which seemed to work. Get yourself a Edelbrock carb they are great! More power, better bottom end, 1st kick starting 90% of the time hot or cold and no flooding ?

:devil:

I 100% agree, you can play with the Pigs jetting till the cows come home and if you're experienced with well tuned bikes you'll never be satisfied with the stock carbs performance.

Edelbrock kicks ass!

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I have 30,000 miles on the Edelbrock--its awesome.

Some times i have to ride Keihin carbed BRP's and it cracks me up to park them on a slight hill or just leaned over a bit on the kick stand and watch the stock carb piss fuel all over the ground!

CRAZY. What a joke. My BSA 441 Victor didnt even do that!

Plus if you lay it down, or stall it going up a hill--then you are in big trouble. Its 90 degrees in the shade and you are now going to have to kick it 10-20 times to clear it, then 1-2 times to find tdc, then 1-5 times to get it started. You will then be exhausted and frustrated and pissed off. And thats if everything goes well!

Woods riders know what its like to stall it on a rut 2/3rds up that single track hill climb--in the mud. Impossible to get a good kick--wrestle that beast around and coast down hill to bump start it and then turn it around at the bottom of the hill and try going up again!

Gawd that stock carb sucks--even if you do get it 'dialed in' --

The Edelbrock takes care of all that. It will run on its side, adjsut for altitude, give ya 1-2 kick starts, great off idle response, in short---it will allow you and your bike to get along better--building a closer relationship and a strong trust--not unlike that between a man and his dog. Soooo for sure Edelbrock is mans best friend.

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