I have a 96 banshee that is piped, ported, advanced timing,TORS removed/regular carb caps, and a K&N filter. The carbs are stock. They have stock needles in 3rd, 30 pilot jets, and 310 mains. I have gone jet sizes 280-310. It runs great until I have it wide open, then it starts misfiring. I don't know wether it's the jets, or if the carbs are opening up too much cuz of the TORS kit or what. Also I am at about 400ft. above sea level.

 

Did this happen when you had the carbs apart ? Tors removed ? If so , maybe the float adjustmnet or maybe you put the slides in backwards ? I have pasted the toomey install instructions below, you might just redo it ,just in case.

Charles '96 Banshee

Read This!
Please understand, that installation of this twist grip kit requires removing the Yamaha T.O.R.S. (Throttle Over-Ride System), of which the thumb throttle is an integral part, and by removing this system you will NOT have the protection from stuck throttles that this system offers. You will therefore be entirely responsible for the proper installation, operation and maintenance of this throttle system. If you don't understand any of the above, you can call us at (805)-239-8870 and we will explain it to you.



Procedure:
First remove the top cap of the stock throttle housing and detach the throttle cable. Next, remove the whole thumb throttle assembly from the handlebars and unplug the connecting electrical wires.

Remove your seat and gas tank to facilitate the cable routing. Take note of where the stock throttle cable has been routed through the frame as you would want to route your new cable in the same manner, assuming the stock throttle cable was routed properly, and you had no binding or pinching problems with the stock cable.

Unplug the wires going from the stock carb tops into the wiring harness. Now, unplug the T.O.R.S. control box located above the left cylinder head, on the frame. (Some people call this the "rev-limiter", but in fact there is NO rev-limiter on a Banshee other than the stock pipes) You must unplug this little black box or the bike won't start.

Locate and remove the gold colored carb top locks on the outsides of each carb. These have a "L" for left and an "R" for right stamped in them so be sure to replace them on the respective carbs when you are done installing the new carb caps supplied with the twist grip kit. Now unscrew the carb tops and remove the tops and cables along with the carb throttle slides/needles and lay this out on your clean work bench. Be careful of the slide needles as they are very fragile and expensive and cannot be used if they become bent.

To remove the carb slides from the stock cables, gather up the throttle return springs with your fingers until the spring is fully compressed into the stock carb top and the slide is left dangling on the cable. There is a gold colored cable keeper-plate inside the slide, notice now, how it is installed and how it keeps the cable in the slide. You will need this information later when you put it back in. This keeper must now be removed, usually by shaking the slide while holding it upside down. The gold colored keeper should fall out of its own weight. If not, you can grab it gently with a small pair of needle-nose pliers and lift it out. Un hook the cable from the slide. Keep the spring, the cable keeper and the slide, you won't need the rest of the stock parts.

Now, wash your hands and clean all parts, as the following operations must be dirt free.

You'll now install the new parts on the new cables. First are the rubber boots. Slide them, small end first, over the cable wire, then up a couple of inches on the cable sheath, (this is on the part of the cable that goes to the carb caps, the short sections).

Next, place the cable wire through the cable adjuster in each carb cap until each cable sheath seats into the cable adjuster. Place the throttle return spring over the cable wire and gather it up against the carb cap just like you did when you had the stock cable and carb cap in your hand, and hook the throttle slide on the cable. Remember how the little gold cable keeper went in? Put it in the same way here, and let the throttle return spring down on it. Be sure now, the spring seats fully inside the slide and the cable is locked in place. Now do the same to the other cable.

Now you're ready to put the slides back into the carbs. Make sure you have the right one in the right side and the left one in the left side. To confirm this, be sure the throttle slide guide pin in the throttle slide bore, in the carb, is lined up with the long groove in the slide AND that the "cutaway"( the beveled edge on the bottom of the slide faces the back of the bike as you sit on it). If you get them in the wrong way, they won't slide all the way down to the bottom of the carb throat floor, like they should. After you get both of them in the right way, screw the carb tops down all the way. Be especially careful as these tops are easy to cross-thread. You can now replace the gold colored carb cap locking plates now too (marked L and R).

Route the cable up through the frame just like the stock one was. In case the stock cable was routed poorly, the criteria is to keep as big a radius as possible everywhere in the cable, to avoid kinks or sharp turns and to insure the cable is fully relaxed when you turn the handlebars from lock to lock, so that nothing will pull or squish the cable.

Using the supplied 4mm Allen wrench, dis-assemble the new twist grip housing. You will have ten parts in total; the upper and lower half of the housing, the cable adjuster, dust boot, the cable guide wheel cover and bolt, the plastic cable guide wheel that guides the cable around the 90o turn it makes from the white handle over to the cable adjuster, the white twist grip handle, and the two pinch bolts. Find and identify all these parts BEFORE proceeding.

Using the white handle as a gauge, slide it on the handlebar as far as it will go, and make a mark on the handlebars showing this point. Remove the white handle and get some #400 wet/dry sand paper and sand the handlebar all the way around making sure you have the area from the end of the bar to your mark, or a little beyond, clean and free of paint, dirt and burrs. It is very important that this area is smooth and clean to insure smooth throttle action. Any burrs, dirt or paint can lead to a stuck throttle.

Insert the throttle cable into the rubber dust boot and the cable adjuster on the upper throttle housing, and pull the cable wire through the upper housing. Slide the white plastic handle all the way on the bar and connect the cable. Place the plastic cable guide wheel in the upper housing as you assemble the wheel and wheel cover plate with the pivot bolt. Assemble the upper housing / cable guide and twist handle, on the bar, with the cable sheath routed above and just behind the master cylinder housing. Put the bottom half of the housing together with the top and run the bolts in so the assembly will remain together but will still slide on the bar. Push the assembly all the way on the bar, then slide it back about a eighth of an inch and then tighten down the bolts. This way you insure that the end of the white handle does not touch the end of the handlebar and rub, causing drag on the twisting action. Be certain of this!

"Blip" (twist) the throttle a couple of times to insure everything works properly, and although everything might not be adjusted properly yet, there is no binding or unusual feel. Confirm the throttle slides bottom out fully on the floor of the carb bore too. There should be approx.. 1/4" of play in the handle end of the throttle cable too, when the throttle slides are fully down. You can now replace the gas tank and seat.

Your next step is to synchronize the two carbs. We recommend the use of a tool called a "UNI-SYN" commonly found in auto parts stores that deal with Volkswagen or sports car parts. This tool is really simple and produces near perfect results.

In the absence of any tools, the manual method will get you really close, if not, right on.

With the air cleaner off the bike you can stick your fingers in the back of the carb and actually feel the slides move. What you hope to accomplish here is to feel which slide moves first, and adjust the other to match it so that they move exactly at the same time.

Using the carb cap cable adjuster on the slide that moves first, adjust the cable play so there is about an eighth of an inch of freeplay between the cable sheath being all the way down in the adjuster and where it is when it starts pulling the slide. Tighten down the lock nut on the cable adjuster and slide the rubber boot down over the adjuster. This one's done. Going to the other side, adjust the carb cap cable adjuster such that when the first carbs' slide just starts to move, this one moves too. Adjust them so they open together. Again, lock the adjuster with the lock nut and slide the boot down to cover the adjuster.

Final check:


The throttle turns smooth and there is no binding when you turn the bars.
Make the cables have an eighth of an inch of play on the carb tops.
Synchronize the carbs and insure they bottom out completely.
Adjust the remaining cable play at the twist grip to about an eighth of an inch. Slide the rubber boot over the adjuster.



Please understand, the adjusters on the carb tops are NOT an idle adjustment! Use the included idle kit for idle control. It is very important that there is the recommended play in the cable system, otherwise there is the possibility of a stuck throttle.