08 apex mtx secondary sheave belt height

[briguy]

I had my side panels off looking at the clutches noticed the belt was down about .5" on secondary I took apart the sheave thinking it was gummed up or bushing was sticking it all looked good I set the spring back to #1 and #6 the same thing again the belt is well broke in and I haven't changed anything on my clutching .Once I start the sled and run it up on the stand the secondary seems to function fine but once you let off back to idle again the belt stays way down below the sheave.I tried it without a belt and it closes up where it supposed to be against the 3 stopper bolts.any suggestions would be appreciated

 

[Len Todd]

The belt wears on its sides. It probably is too narrow. Measure the belt width. Nimimum width = 1.28" A new belt = 1.34"

Also, someone could have removed the washers on the adjusting bolts on the backside of the secondary. This allows the bolts to be screwed in too far resulting in the belt sitting low in the Secondary.

But, I think your belt is just wore out. How many miles do you have one it?

 

[briguy]

08 apex secondary

it's a broke in belt maybe 5 hours on it but I also tried a brand new yamaha belt? if I turn the sheave by hand 3 or 4 times the belt climbs right up to where it's supposed to be and my primary is completely open when the engine is sitting at idle.I have a hard time believing it's the 3 stopper bolts holding me up but I'll try reshimming them.

 

[ROCKRTX]

Re: 08 apex secondary

it's a broke in belt maybe 5 hours on it but I also tried a brand new yamaha belt? if I turn the sheave by hand 3 or 4 times the belt climbs right up to where it's supposed to be and my primary is completely open when the engine is sitting at idle.I have a hard time believing it's the 3 stopper bolts holding me up but I'll try reshimming them.

How much your old belt width mesure? I change mine at 33mm,spec say 32.5mm min.I play with 2 set of washer for my secondary.

If your belt is too low in secondary ad washer on the 3 bolt behind.

 

[Len Todd]

One other thing, ... The Secondary has to roll to a stop for the belt to raise up to the top.

What I would do to adjust the secondary is remove the belt from the PRIMARY and lay it in the secondary. Adjust the Seconday's shims such that the belt lays ~ 1/16" above to flush with the top of the Secondary.

 

[briguy]

08 apex secondary

that's what I ended up doing pulled the belt off checked my height and left it.I also tried a older dayco belt which is much softer than than the new yamaha belt it climbs to the the top off the sheave much quicker.Anyway I'm gonna leave it for now until I get into the snow I'm not sure but I could be makin a mountain out off a mole hill here.Thanks for all the help.

 

[Len Todd]

If the belt lays in the sheave flush or slightly above the sheave, you are O.K.

 

[Bigvander]

Belt sits low

My belt is sitting 1/4" below and the belt width measurement is the exact same as a new belt. What are the 3 stopper bolts that you are referring to? Do I need to add another washer to the backside of the clutch on the shaft?

 

[grader]

remove the secondary from the shaft and on the back side are 3 8mm bolts. these bolts adjust the sheave separation by adding or subtracting washers under them. belt will ride highest with bolts removed.

 

[Bigvander]

Belt sits low

So all I need to do is remove those bolts and add a washer? Or do I remove a washer? I guess it will make more sense after I remove the clutch. Can I add any washer or is it a Yamaha part?

Thanks for the help!

 

[grader]

the bolts bottom out on the opposite sheave, so with no bolts it closes the sheaves, raising the belt. you can use washers from the hardware store, just try to use 3 the same thickness. best performance is with the belt as high as possible but your belt might squeel at idle as it drags on the shaft of the primary clutch.

 

[Bigvander]

Belt sits low

I removed the clutch and the belt is flush now. When the clutch and belt were installed it sat 3/16" low. Is this normal or do I need to add a shim? Thanks.

 

[grader]

when you run the track on a stand when it stops it might not be at the top of the sheaves, this is normal. when on the trail it coasts to a stop and goes to the top. bolts can easily be adjusted or even removed and if the belt does not squeel at idle, your good to go. changing belts can make it squeel as they may be shorter or wider. the center to center distance also affects belt ride height.

 

[Bigvander]

Belt sits low

Okay thanks. Well if I'll get better performance with the belt higher I'll add a shim, unless it starts to squeal. I've had to adjust center to center before and it was not fun, hopefully that is not the issue. Thanks again!