Uncorking Question

6 replies to this topic
  • BroTank

Posted December 13, 2004 - 11:44 AM


I did search the forum before I started this question but wasn't able to find what I needed? It may be here but I can't find it. So here goes.

I uncorked my xr650r (mostly) Jets, air box, exhaust. But I could not get to the needle. Mind you that I am not the most mechanically minded person but I was able to do the other mods ok, 2 hrs (not bad for me). Anyway, that was Friday and Saturday was to be my second weekend riding, so I closed it back up and it ran fine, but I would still like to change my needle position. Any helpful hints? What is the correct procedure to get to the needle?

BTW, I uncorked only because it ran a little hot on me last weekend and everything points to this as a good solution. This weekend I didn't have that problem but I wasn't really riding tight trails this weekend. I did notice that if I rev'd up the engine wouldn't idle back down immediately. I assume this is because the needle needs to be adjusted.

Thanks for any help you can give. I diagram would be great if anyone has one. I've not see one for my bike but several on the internet that are supposed to be similar.

  • zx7rye

Posted December 13, 2004 - 02:24 PM


You're still lean... You're not on the needle @ idle. What did you change during the rejet? As far as getting to the needle (maybe someone has a better way) I removed the throttle linkage and detent spring in order to access the slide. The needle is encapsulated (like that word) under ( I believe) 2 over torqued phillips heads. I found it is easier to undo the linkage because you aren't fighting the throttle detent spring. Use a correct fitting screw driver and with a light tap on the back end of the screw driver loosen the screws to access the needle. Swap it out. I went with the 3rd position on the clip. I will be upping my main from a 172 to a 175 as it's a bit lean for my locale. Sealevel...coldass Boston.

  • resslera

Posted December 13, 2004 - 07:11 PM


With the hanging idle try this. Just turn down your idle some with the idle adjustment screw. I complained of this problem to the local dealer on my 650R and sure enough it worked like a charm. Happened every time when bike was warm before, hasn't happened since turning idle down.

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  • roosty

Posted December 13, 2004 - 07:30 PM


what was the airbox mod you performed? My bike has the power up kit that came with it new...40mm intake manifold, 175 main jet. Plus I installed the HRC competition baffle. These mods made the bike a real runner. If you modified the side cover for more airflow (aka HRCs team bikes) then Honda recommends a 185 main jet. Hope this info helps.

  • smashinz2002

Posted December 13, 2004 - 08:52 PM


The bike really isn't going to run right until the needle is moved to the 3rd position (middle) for the B3E needle, or the 4th position (down from top) for the stock needle.
To change the needle position, it's not necessary to remove the carb. It can be swiveled to the right hand side to remove the top of the carb and get to the piston slide. I've done it that way several times when experimenting with different needle settings.
From memory it's difficult to describe the procedure step by step, but for sure you have to take the throttle linkage off. Not the cables, but there is a little bracket holding the cables mounted by a small screw. Remove that and the assembly will fall to the side where you can then twist the throttle open at the carb to remove both cable ends from the linkage. Once the cables are out of the way, you have to remove the top of the carb.
Once in there, you'll see that the piston slide lever is held in place with one screw. Remove the screw and the spring will unwind to a resting position, then remove the return spring. Now carefully pull out the linkage from the side of the carb. There is a very thin plastic bushing in there, note it's position and don't lose it. After that part is removed, you can pull out the piston slide with attached lever arm.
Using a long, skinny, phillips screwdriver with magnetic tip, reach into the piston and remove the two little screws. Those hold the needle in place. Once those are out, you can just pop out the needle and change the position of the circlip. Remember, going further down on the clip position raises the clip and richens the mixture. Going up the needle leans it out. If you have the stock needle, the setting should be changed to 4th groove down from the top. If you have the B3E needle, set it right in the middle.
If you get all that done, and get it back together correctly, and making sure everything else on the bike is properly uncorked and jetted right, the bike will run extremely well, never overheat, and have a lot more power than stock.
Good luck with it man! Any more questions just ask. I've had my 650R for over four years, so I'm pretty familiar with it now :cry:

  • zx7rye

Posted December 14, 2004 - 05:19 AM


With the hanging idle try this. Just turn down your idle some with the idle adjustment screw. I complained of this problem to the local dealer on my 650R and sure enough it worked like a charm. Happened every time when bike was warm before, hasn't happened since turning idle down.

But if your masking a lean condition with an idle adjustment, you are asking for trouble.

  • BroTank

Posted December 14, 2004 - 09:56 AM


Thanks to All. I will open her back up this weekend. I will post my results.

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