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Workshop => Engine and Bottom End => Topic started by: genoapb on September 07, 2013, 09:13:38 AM

Title: throttle for big carb?
Post by: genoapb on September 07, 2013, 09:13:38 AM

what are you guys using for a throttle on the big carbs? I have a 52mm crank shop carb with a modified stock throttle which worked for my 44mm lectron but its not opening the bigger one up all the way. thanks

Title: throttle for big carb?
Post by: seanoktm on September 08, 2013, 12:26:27 PM

A billet thumb throttle is going to be your best bet. http://www.amazon.com/Moose-Racing-ATV-Thumb-Throttle/dp/B001A6KJZO. I use a moose racing billet one like i posted. I have used a stock 250r one before with my 50mm lectorn and a 48mm lectron but you have to grind on them so it will open them all the way.

Title: throttle for big carb?
Post by: rsss396 on September 08, 2013, 12:30:02 PM

I had to grind like a mofo on my billet throttle for the 56mm CS, Mike and Jeramey some how made the stock throttle work with their 52mm CS

Title: throttle for big carb?
Post by: atv fan 28 on September 08, 2013, 01:15:24 PM

i use a Terry Cable housing and cable for my Cutler.

http://www.terrycable.com/Billet-Aluminum-Thumb-Throttle_p_21.html

Title: throttle for big carb?
Post by: Morse250r on September 08, 2013, 01:47:40 PM

Terry cable set up for me as well

Title: throttle for big carb?
Post by: rsss396 on September 08, 2013, 02:18:54 PM

That terry cable almost looks exactly like my billet chariot throttle, you do have grind them for a 52 round, Wayne you are 48X58 but you only have to lift the slide 48mm.

Title: throttle for big carb?
Post by: seanoktm on September 08, 2013, 03:21:26 PM

When i had a stock thumb throttle on my bike with my 50mm i would make a cable adjustment then find out the slide was not opening all the way. Would hang down about 3/16".

Title: throttle for big carb?
Post by: rsss396 on September 08, 2013, 04:36:26 PM

yeah the guys with the 52 and a stock thumb throttle have to of made the wall of the throttle thin as paper at the ends of its travel to make it work, but that is their style :)

Title: throttle for big carb?
Post by: traxman on September 09, 2013, 12:22:51 AM

It's real simple to make a oem open a 52 with about 5-10 minutes of mod's without grinding on the walls of the housing. I'll snap some pictures and show you how to do it hopefully tomorrow. Bike's across town right now.

Title: throttle for big carb?
Post by: genoapb on September 09, 2013, 06:36:09 AM

thanks for all the replies fellas, ive ground on the stock one too and im getting about 90% open.

Title: throttle for big carb?
Post by: traxman on September 10, 2013, 01:31:06 AM

Here in this first picture where the zip tie is pointed you'll notice there's a little metal stop tab that's cut off. This allows the body to be the actual stop.  When determining throttle travel make sure your cover is on because it will limit it compared to having it off.
 
 (http://i925.photobucket.com/albums/ad97/4traxman/IMG_1444.jpg) (http://s925.photobucket.com/user/4traxman/media/IMG_1444.jpg.html)

Here in the second picture I ground off enough material to get the desired amount of throttle travel. This throttle easily opens a Crankshop 54mm and pretty sure it has enough to do a 56mm.
 (http://i925.photobucket.com/albums/ad97/4traxman/IMG_1445.jpg) (http://s925.photobucket.com/user/4traxman/media/IMG_1445.jpg.html)
 
Removing material allows throttle to close all the way. I used a 4" peanut grinder with a 80 grit flapper wheel to modify the parts.

(http://i925.photobucket.com/albums/ad97/4traxman/IMG_1446.jpg) (http://s925.photobucket.com/user/4traxman/media/IMG_1446.jpg.html)

Hope this helps you out Geno..