Yeah - another Edelbrock question

O.K. - '06 xr650r, uncorked with Edelbrock, 17e needle (I believe), 12 clicks from rich. Bike starts easy, runs great, plug is nice tan color. Usually ride around 2500' elevation (California High Desert). Under load - especially in 4th and 5th gear I'm getting that "marbles in a can noise". I don't think it's pre ignition, but it sure sounds like it. I am assuming it's the counterbalance gears but not sure. Any ideas?

O.K. - '06 xr650r, uncorked with Edelbrock, 17e needle (I believe), 12 clicks from rich. Bike starts easy, runs great, plug is nice tan color. Usually ride around 2500' elevation (California High Desert). Under load - especially in 4th and 5th gear I'm getting that "marbles in a can noise". I don't think it's pre ignition, but it sure sounds like it. I am assuming it's the counterbalance gears but not sure. Any ideas?

Try a colder plug under the same conditions.

O.K. - '06 xr650r, uncorked with Edelbrock, 17e needle I'm getting that "marbles in a can noise". I don't think it's pre ignition, but it sure sounds like it. ideas?

I have an Edelbrock that I have used on two stock XR600s and an HRC628. I had to run a 19E needle in all three bikes with the needle adjuster anywhere from 4-8 clicks from full rich in order to get a proper fuel mixture. The " marbles in a can" sound probably is detonation, sounds like you need to go richer.

I guess thats my question - for So Cal xr650r riders - are you running a 17e or 19e?

I use the biggest needle... and I'm right in the middle between rich & lean, it runs perfect, and leaves a lot of room to make any necessary changes up or down! When you hear marbles... what RPM are you at? could it be that you just need to down shift because you are lugging the engine too much? just a thought!

I run 18E needles in my 650R's.

Maybe its the quality of your gas, Causing the preignition you hear..... :thumbsup:

Maybe its the quality of your gas, Causing the preignition you hear..... :thumbsup:

And what octane are you using???

Thanks for the back feed. No, not lugging it, it's a mid to upper range rpm problem so I don't think it's a mixture screw fix - more like a richer needle fix, and I always use 91 octane (Cali hi test). I pulled the tank off last night to make sure the intake clamps were tight - the carb was at 15 clicks from rich, thought I was at 13. Backed it off a few clicks. I'm going up to the desert this weekend to try it again. I wish I had an 18e needle - all I have right now is a 19e - kind of feel this will be too much. Hate swapping the needle out in the desert but you gotta do what you gotta do.

Since you already have the 19E, why not go ahead and put it in and see how it works?

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