the moving of neutral is a good thing, BUT????
this will change the relationship of the belt in the clutch to the contact point on the weight at any given speed. if this is the only thing that is changed it will change all rpms. it is still good to do this as it is better for belt, clutch and speed. if installing any adjustable weights do this first and then adjust, if you do it after some changes will need to be made after to compensate.
when i say speed may be affected i say that because yamaha stock split collars are the first thing to make contact on full shift out. i forgo the purchase of premade split collars as the ones i bought from company above were so far off that the sheave runout was off. buy new ones and use a belt sander or new file to thin them. keep checking with a set of calipers and make them the same thickness accross. takes some time but they will be right.
dont buy extra ones as im sure you wont make a mistake
this will change the relationship of the belt in the clutch to the contact point on the weight at any given speed. if this is the only thing that is changed it will change all rpms. it is still good to do this as it is better for belt, clutch and speed. if installing any adjustable weights do this first and then adjust, if you do it after some changes will need to be made after to compensate.
when i say speed may be affected i say that because yamaha stock split collars are the first thing to make contact on full shift out. i forgo the purchase of premade split collars as the ones i bought from company above were so far off that the sheave runout was off. buy new ones and use a belt sander or new file to thin them. keep checking with a set of calipers and make them the same thickness accross. takes some time but they will be right.
dont buy extra ones as im sure you wont make a mistake
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- 2014 Yamaha SR Viper LTX, 2014 Yamaha SR Viper RTX SE, 2015 Yamaha SR Viper MTX SE 162 (turbo), 2015 Yamaha SR Viper MTX SE 153
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Also when replacing the split collars make sure to put blue loctite on the post and make sure it's spread EVENLY around it or you will crack the stationary sheave after only a few rides.
SuperStroker!
Pro
Re: belt clerance
Anyone who knows anything about clutches in general, knows that when (on a Yamaha clutch) you screw the spider deeper into the stationary sheave, it moves the "movable sheave and spider" closer to the belt by that distance (in my example above it was .060" closer and in this example its 1/2 " farther away) This is what changes the point ON THE CAM ARM, where the roller first makes contact ON THE SHIFT CURVE OF THE CAM ARM. This determins what the Cg location of the cam arm will be upon belt engagement!
Look at it this way. Leave the damn split collars just as they are, STOCK and find a belt that has 1500 trail miles on it and measure the width, the belt will be narrower by some amount. Lets say its 1/2 inch (I know it wont wear that much, just using this extreme to demomstrate my point).
This has the same effect as changing the split collars, with regard to the change in location on the cam arm where the roller and weight arm meet, upon engagement of the movable sheave to the contact surface of the belt.
IF YOU PUT A 1/2" larger diameter roller in the clutch, (I know they wont fit) that contact point between the cam arm and roller will now remain the same, because you made up for the worn, norrow belt with the larger roller. Now when the movable engages the belt, the roller meets the weight at the same realitive point on the cam arms shift surface. If you left the stock roller in and put a 1/2" narrower belt on, because the movable will have to travel that 1/2" farther, (close the clutches farther to meet the narrower belt) the roller will meet the cam arm farther up the shift curve of the cam arm...the arm will have to swing out farther to meet the roller.
This means the Cg location of the arm, the mass balance for force the arm exerts through the roller and onto the side of the belt has changed.
THIS MEANS YOUR TUNEUP JUST CHANGED substantially! It's the same as changing to a different split collar, IT CHANGES A LOT OF THINGS, with regard to the way your clutches handle the motor torque!
Read my above note and think about how the details I pointed out, will change the way your tuneup responds and use some of these details to help you go faster!
John, you are correct about the relationship between the spider and movable sheave in neutral. I machine that surface too, just like you when I want to move the spider shim closer and pull the cam arms closer to the Cg. I know this doesnt change unless you machine the spider. Thats a whole different discussion. We can talk about that too!
But thats not what I was talking about!
black john said:any one who knows any thing about yamaha clutches knowes that by tighting up the belt clerance does not change the arm to roller relation ship as you only move the iner sheve not the spider as with the brand X sleds. this ajustment stops the hard slam on the belt ,reduces track spin and increses power transfer to the track also inproves belt life. and even if it did move the roller arm relatio ship theres differnt rollers sizes 14.5 -15-15.6-16-18.5 mm all readly avlable
Anyone who knows anything about clutches in general, knows that when (on a Yamaha clutch) you screw the spider deeper into the stationary sheave, it moves the "movable sheave and spider" closer to the belt by that distance (in my example above it was .060" closer and in this example its 1/2 " farther away) This is what changes the point ON THE CAM ARM, where the roller first makes contact ON THE SHIFT CURVE OF THE CAM ARM. This determins what the Cg location of the cam arm will be upon belt engagement!
Look at it this way. Leave the damn split collars just as they are, STOCK and find a belt that has 1500 trail miles on it and measure the width, the belt will be narrower by some amount. Lets say its 1/2 inch (I know it wont wear that much, just using this extreme to demomstrate my point).
This has the same effect as changing the split collars, with regard to the change in location on the cam arm where the roller and weight arm meet, upon engagement of the movable sheave to the contact surface of the belt.
IF YOU PUT A 1/2" larger diameter roller in the clutch, (I know they wont fit) that contact point between the cam arm and roller will now remain the same, because you made up for the worn, norrow belt with the larger roller. Now when the movable engages the belt, the roller meets the weight at the same realitive point on the cam arms shift surface. If you left the stock roller in and put a 1/2" narrower belt on, because the movable will have to travel that 1/2" farther, (close the clutches farther to meet the narrower belt) the roller will meet the cam arm farther up the shift curve of the cam arm...the arm will have to swing out farther to meet the roller.
This means the Cg location of the arm, the mass balance for force the arm exerts through the roller and onto the side of the belt has changed.
THIS MEANS YOUR TUNEUP JUST CHANGED substantially! It's the same as changing to a different split collar, IT CHANGES A LOT OF THINGS, with regard to the way your clutches handle the motor torque!
Read my above note and think about how the details I pointed out, will change the way your tuneup responds and use some of these details to help you go faster!
John, you are correct about the relationship between the spider and movable sheave in neutral. I machine that surface too, just like you when I want to move the spider shim closer and pull the cam arms closer to the Cg. I know this doesnt change unless you machine the spider. Thats a whole different discussion. We can talk about that too!
But thats not what I was talking about!
SuperStroker!
Pro
Buckeye said:
Everything you said up to here is true. The "bold" comment isn't correct.
The point where the roller touches the cam arm changes when you change the thickness of the split collar or the width of the belt, without changing the split collar.
This is as far from "everything else stays the same" as you can get! The roller to shift curve contact point is extremely critical to the way the clutch shifts against the power curve of the motor.
Frostbite
TY 4 Stroke God
So, how much thinner split collars should get (or make)? The ones I pulled out are .130" thick. Should I sand them down .060? Then I'd have collars .070 thick. I see there is a taper on these, which side do you sand off the thicker side or the the thinner side?
The more I look at this I'd rather just buy new ones. I can just see these little guys flying across the room as I try to hold them with my vice grips against the belt sander.
So, If I do buy them. How thick should they be?
Frosty
The more I look at this I'd rather just buy new ones. I can just see these little guys flying across the room as I try to hold them with my vice grips against the belt sander.
So, If I do buy them. How thick should they be?
Frosty
What are you trying to achieve??????
