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brady-yzf

Quarter-turn throttle on XR-650R

23 posts in this topic

I want to put a quarter-turn throttle on my '04 xr 650r, the half turn has me choking up each time I want to give it full throttle, which makes it tough to get back off of the gas quickly. That and when I do give it full throttle, it's tough to keep my elbows up. The result is that by the end of something like the Baja 500, I'm too tired/lazy to keep giving it full throttle out of the turns. Has anyone done this? Does anyone know if a crf 450 throttle tube will work on the bike? I have the Edelbrock carb. Thanks for the input.

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I want to put a quarter-turn throttle on my '04 xr 650r, the half turn has me choking up each time I want to give it full throttle, which makes it tough to get back off of the gas quickly. That and when I do give it full throttle, it's tough to keep my elbows up. The result is that by the end of something like the Baja 500, I'm too tired/lazy to keep giving it full throttle out of the turns. Has anyone done this? Does anyone know if a crf 450 throttle tube will work on the bike? I have the Edelbrock carb. Thanks for the input.

Most people would be a little tired after a solo 500.

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I just installed an Edelbrock carb on my XRR and was wondering the same thing about hte throttle travel. Does anyone know what application the throttle tube and cables included with the kit came from originally?

If nothing is available, I'd be thinking about machining a new, larger diameter throttle wheel to replace the stock one on the carb. If anyone else would be interested, let me know and I could whip out a batch pretty easily.

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u should try an endurance work out!! its not for strength or speed really, just stamina. used to do that stuff when i ran track. i could surf forever, run, play, everything.

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It's hard to believe that there's not really already a solution for this out there somewhere. I know the moderators are kind of sensitive about people spamming or promoting products on this forum, so I should say that I'm NOT looking to make or sell anything for a profit. If nobody offers anything up over the weekend, I'll look into making a larger diameter throttle wheel (or whatever it's called) sometime next week.

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You're the man, gato! I don't know if the stock carb has this issue, I'm gonna contact Edelbrock and see if they know anything. Whatever their answer, I know it will mean me carrying one more SAE tool with me in my otherwise metric toolkit!

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I just bought one of the G2 tubes with the Y-25 cam. I'll let you know if it works. The guy claims it will reduce the rotation of the Motion-Pro 01-0073 (the tube sent with the Edelbrock ) by 20%. That seems like about the right amount to me.

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You can also reduce the size of the wheel on the Edelbrock carb to change the ratio instead of making anew throttle tube. Furthermore, you can change the eccentricity so you have smooth response at the lower throttle opening position with a progressive change to the upper (wide open) throttle range. This would probably be quite a bit cheaper than a new throttle tube.

I have made these progressive throttle cable wheels for custom fuel injection throttle bodies in the past on race car applications.

Unfortunately, I don't have an Edelbrock to make new throttle cable wheel. Let me know if you guys want some help and I can look into it. You may also ask Edelbrock. I'm guessing if they are willing to overbore a carb, they should be up for suggestions to making their product better suited to the application.

Just trying to save you some $$.

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Edelbrock unfortunatley has become less willing to service their own carbs. I had talked to Chris at Edelbrock not too long ago when I was ordering a part for a friend. I asked about carb boring and rebuilding/servicing. He said they are no longer willing to do either of the procedures. For someone to rebuild/reservice their carb, Edelbrock will sell them a rebuild kit with all the seals and such for them to do it themselves or have someone else do it, :lol: It makes me wonder what is going on the Edelbrocks customer service now. :applause: :applause:

This just made me think more about this and I will post this into it's own thread.

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Just a note: a 1/4 turn throttle will open up the carb slide quicker, but the stock carb doesn't have a accel pump, is that going to cause a stumble when cracking the throttle hard and quick?

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I'm reading Bradys first post here and not quite understanding it.

You shouldn't be off the gas then fully on the gas repeatedly. That's not going to make you faster but it will make you more tired and make more rapid bike wear. You should concentrate on your technique, your riding style, smoothness. You need to flow more and maintain momentum, not be hard on hard off the gas.

You ever watch how the fast Baja guys ride? They look like they're going slow, it's actually boring to watch, they're smooth.

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Anyone interested if I made a prototype modified Throttle Cable Wheel for the stock carb? Not sure how much it would cost to make, but I can ask.

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From the discussion, it seems that a prototype for the stock carb would want to open quicker only during the last third or quarter of travel. I would be interested if the results are good. For me, holding the throttle open on long dual sport rides could be made easier if less twisting is required.

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I have install a motion pro Cr type throttle on my Xrl that has an edelbrock. I had to remove one of the cable and make some fitting in the throttle to make the cable fit at the adjustment and it works great. No more 1 full turn to be wot.

Martin

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