KymcoForum.com
Scooters - 50cc => Agility 50 => Topic started by: blue on February 19, 2012, 02:27:40 AM
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was thinking of useing my old v boss the stock one . What would happen if I shorten it by shaving it down would that work and let the belt ride up higher for a better ride or is that a no no. and how much should I take off.
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the stock one has the niple on it yet and was thinking of cut that right off but that looks like takeing off to much.
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That's another balancing act. If you are leaving lets say 4mm unused on your var. You have to find out if the rear pulley is completely open. If it is then you need a 2mm longer belt. If its not then cutting the boss 4mm will get you to the top. The trouble there is when the var opens the belt may not get all the way down to the boss reducing take off. A proper match of belt size, and boss length make it all work together. I had to add shims to the boss to get the belt down to the boss, and use a longer belt to get it all correct.
First find out exactly what your set up is doing. The Sharpie marker on the pulleys works best. Draw lines from bottom to top, front pulley, and rear. Then ride. That will show you the travel you have now.
Post up the results, and I'll help you figure it out. This kind of tunning helps to dial in the engine better as there are no variables in the cvt once you get that done.
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the thing I worry about is the belt hiting the top to high and hiting the elc. start that would be a big ouch.
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It will only do that when it breaks... No worries! See if you cut the boss, and the belt is already at the bottom of the rear, the var will keep pressure on it till it snaps. The belt needs to "seat" at both ends to relieve the pressure.
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mmm ok that makes sense thanks I think ill give it a try.
Does this also give me more options for dif.size belts.
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..i'm currently running a 1.470 drive boss...kinda like it since i gotta narrow belt...old...need a 737, like streido...wanna try that...
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he thing I worry about is the belt hiting the top to high and hiting the elc. start that would be a big ouch.
..it happens..kinda wear a slight groove in the outside of the belt...
..not really of much concern there as long as you change your belt more often...
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That's what I'm saying. I have a bunch of different size belts that didn't fit my needs. They all have less than (1) city block on them. They'll fit something tho. The bitch about it is you can't buy cheap belts and expect them to last so 45 50 bucks a pop... They add up! Just post up the #'s you get from marking it, and the size posted for your belt.
Keep one more thing in mind... Belt width! W/ the belt, and cvt parts removed put the belt in the clutch pulley. Your belt should be = to or above the top of the pulleys. If not get a wider belt. Once you have the right width close the var, and mark the top of the belt. Don't expect it to go higher than that. BUT the right length belt will reach that mark. to get the right length you have to be SURE the belt rides TIGHT on the drive boss when the scoot is stationary. NO SLIP. If the belt is too long it will erase the highest mark on the var by flopping around, and not transferring power. But it wont be if you follow the first steps.
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...good point z...
..what i look for more, is the amount of travel the belt shows on the driven pulleys..if i know that i'm hitting the top of the variator...
..that's how i know that the 729 aint living up to the cvt's full potential right now on kymmi...
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That's kinda my point Bro! Even at the top of the Var. you may NOT be at the bottom of the Torque drive if the belt is tooooo thin/tooooooo long. You gotta start there (at the torque drive). The only thing that has to remain constant is the ramp angle of the belt. (faster wear(for all cvt parts) if you don't) It's more the cvt controls the engine than the engine controlling the cvt. Oh yeah baby... Now u get it! Dirty girl~
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:o Wow I hope my brain can soak all this in. while trying all this is there anything I should becarful of so I don't damage the scoot.
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One indicator that you haven't got it right is if the CVT gets hot. Feel the outside of the case after any mod and a short ride. If it's hotter than normal, go back and undo or change what you just did.
Check that your variator isn't loose on the boss -- that is, boss should be a perfect fit inside the variator. If it can rattle around, one or the other is worn out and needs replaced. Rattling creates heat, loss of power, and inconsistancy so it'll be hard to figure out what else is needed till those are in spec.
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"Check that your variator isn't loose on the boss -- that is, boss should be a perfect fit inside the variator. If it can rattle around, one or the other is worn out and needs replaced. Rattling creates heat, loss of power, and inconsistancy so it'll be hard to figure out what else is needed till those are in spec."
zactlee! Watch out for beer too!
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..i'm currently running a 1.470 drive boss...kinda like it since i gotta narrow belt...old...need a 737, like streido...wanna try that...
I put my belt in a while ago and it still feels good. Just had a look on the malossi belt chart and im sure mine is the 736x17x30 belt. They do a 738 too. Mine seemed to take a couple of miles to settle in when i 1st fitted it but its been good after that. When i measured it against the stock belt it looked longer when sat side by side but i measured them round the outside and it came out the same twice, that kijda confused me so i just put it in and tried it anyway. Either my measuring was out or i just had a mental episode that day ;D
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Belt sizes are a pain in the ---. They never match up. Even the "official" charts vary. I just posted up in Blues thread on belts how to size one up correctly. The 2 main points are: The belt must be at the top of the rear pulleys, and it must sit tight on the drive boss when stationary. Longer/shorter, and you lose potential gear range. Kevlar belts, are softer rubber, and grip better but wear thin quicker. Poly.belts wear longer but stretch over time. Kevlar should only be used in Hi Perf. scoots as they are inspected more often. Poly belts are better in stock scoots as they last longer overall