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Due to the bashing by TWIT's I said I would not post any more tech....but lets try one last time and see if we can share some tech and be adult.
And yes that is not a Viper secondary it is one of my old throw away secondary's that sat under the grinder, but the parts are the same
8DN on Viper made easy.
1. Secondary clutch shims.
a. Shims required for 8DN belt. This is different from other shims like helix shims or center shims.
On the back of the secondary clutch are 3 small bolts. (see first pic below one bolt removed) They push in and hold the secondary apart to adjust belt deflection in the closed or stopped position (that is in simple terms the belt slack or tightness). Yes I know why so archaic of a method for belt deflection. Anyways those of you that rode Yamaha very long know these bolts get beat up and shorten and you have to replace them when the deflection changes usually noticed by belt squealing and sled trying to creep at idle. So new bolts if the belt rides too high over the sheave, and add washers if the belt rides too low.
So when you install an 8DN belt you need to check deflection. When the ribs just stick above the sheave you are correct. This in my opinion is not an exact science so a little leeway is ok here as long as it is close (disclaimer: close is relative term though) The second pic below is close to what I consider proper belt deflection, maybe a hair high. (not going to adjust it a hair for this pic...lol)
So when you add an 8DN belt you may need to add another washer to this bolt to space apart the sheaves for proper belt deflection and getting the 8DN to the deflection shown above. Shown in 3rd pic below is a bolt and everyday garden variety of washer added for most 8DN installs (NOTE: some 8DN go on and do not need any adjustment) Obviously same size washer set on all 3 bolts. You can also have machining done instead of washer but it is not necessary. You still have secondary off, wrap belt around sheave and check deflection. Reinstall when correct.
NOTE!!!!!!!!!!! Belts have a lot of difference even when new, check deflection when changing belts even the same size belts.
2. Helix shims
a. Helix shims are for reducing the secondary coil spring bind. The best way is to have your secondary or helix machined to get rid of coil bind but if you choose instead to shim the helix (this is usually used to test whether coil bind is affecting you to decide if you wish to machine your parts) this is how. NOTE: this is not the recommended long term solution to coil bind.
Remove Helix and put 3 washers all the same size on the studs as shown in the last pic below and bolt helix back on. Test and decide if you wish to machine your secondary or helix and THEN REMOVE WASHERS as this is not the recommended way and put here only to remove confusion about the different secondary shims being discussed.
And yes that is not a Viper secondary it is one of my old throw away secondary's that sat under the grinder, but the parts are the same
8DN on Viper made easy.
1. Secondary clutch shims.
a. Shims required for 8DN belt. This is different from other shims like helix shims or center shims.
On the back of the secondary clutch are 3 small bolts. (see first pic below one bolt removed) They push in and hold the secondary apart to adjust belt deflection in the closed or stopped position (that is in simple terms the belt slack or tightness). Yes I know why so archaic of a method for belt deflection. Anyways those of you that rode Yamaha very long know these bolts get beat up and shorten and you have to replace them when the deflection changes usually noticed by belt squealing and sled trying to creep at idle. So new bolts if the belt rides too high over the sheave, and add washers if the belt rides too low.
So when you install an 8DN belt you need to check deflection. When the ribs just stick above the sheave you are correct. This in my opinion is not an exact science so a little leeway is ok here as long as it is close (disclaimer: close is relative term though) The second pic below is close to what I consider proper belt deflection, maybe a hair high. (not going to adjust it a hair for this pic...lol)
So when you add an 8DN belt you may need to add another washer to this bolt to space apart the sheaves for proper belt deflection and getting the 8DN to the deflection shown above. Shown in 3rd pic below is a bolt and everyday garden variety of washer added for most 8DN installs (NOTE: some 8DN go on and do not need any adjustment) Obviously same size washer set on all 3 bolts. You can also have machining done instead of washer but it is not necessary. You still have secondary off, wrap belt around sheave and check deflection. Reinstall when correct.
NOTE!!!!!!!!!!! Belts have a lot of difference even when new, check deflection when changing belts even the same size belts.
2. Helix shims
a. Helix shims are for reducing the secondary coil spring bind. The best way is to have your secondary or helix machined to get rid of coil bind but if you choose instead to shim the helix (this is usually used to test whether coil bind is affecting you to decide if you wish to machine your parts) this is how. NOTE: this is not the recommended long term solution to coil bind.
Remove Helix and put 3 washers all the same size on the studs as shown in the last pic below and bolt helix back on. Test and decide if you wish to machine your secondary or helix and THEN REMOVE WASHERS as this is not the recommended way and put here only to remove confusion about the different secondary shims being discussed.
