2011 Hisun 700 Primary Sheave Not Closing Completely

[djl]

Hi All!  I thought that the drive system was making a bit more noise than I expected so I secured the belt drive cover aside and ran up the rpms in neutral to check for bearing noise, etc.  There wasn't any noise but I did notice that the primary sheave did not close as far as I expected, the belt only came within ~3/4" from the top of the sheave.  See video link below (I was unable to upload it directly).  I ran the RPMs up 5,000 (manual indicates that this is max for this engine).  Is this expected behavior or should I remove the primary sheave and check roller diameters, clean & re-grease everything?  I will be traveling with newer machines so want to be sure that I can travel as fast as this machine is capable.  🙂 Thanks in advance!

https://www.dropbox.com/scl/fi/qof63w1kohal8wzmikfpt/IMG_0234.MOV?rlkey=j4h8ejm0ogjvlluyy5olagvrn&dl=0

[djl]

Hi All.  I believe that I found the problem.  Where it was raining today I dismantled the primary sheave assembly and the grease had hardened and piled up against the outer reaches of sheave travel (see attached photos - yikes!).  I performed the primary clutch sheave service as described in the service manual.  The diameter of the weights were within spec but a couple of them had flat spots.  I also noticed that the steel plate had grooves worn in it in a couple of spots, and the primary sheaves appeared to have 'grooves' where the belt was prevented from riding any higher on them.  I cleaned everything up, re-greased and re-installed.  In neutral the belt will now ride up to the top of the primary sheave but only if you accelerate the engine hard.  It still prefers to run in the 'groove' but I am hopeful that with the additional load introduced by the machine that the groove will not play as big a role.  🤔

[Greg Kilgore]

I'm no expert by any means. But I'm 99.9% sure that there should be no where near that much grease inside the Primary sheave area.

From what I've seen. There should only be grease on the plastic pieces that fit over the opening on the roller plate. Where the plastic pieces meet the wall of the sheave. Where the red is in your pic below.

 

Reason for only minimum grease. That gets belt gets HOT. If a lot of grease then it could liquify and get all over the belt. That would cause the belt to slip. Even water will cause the belt to slip. 

As you know the rollers are weights. The weights roll to the outside. Making the outer part of sheave move in. Making the belt ride higher. From reading other sites. A gram of weight per roller makes a big difference. Motor cycle dr should have replacement parts for that machine. Or ever upgraded slider setups.

But on the good side. People buy shims to put between the sheave and sheave nut. To make the belt ride a little lower. It does subtract from the top end. But puts a little more pulling power to the rear wheels. 

 

Hope your ride goes well.

 

And be careful with the cvt belts. Had a cvt belt had a catastrophic failure on me and the wife. Belt wrapped around the main and secondary sheaves. Locked the rear end. We sent sliding down the blacktop. We landed on the driverside on edge of road. Got very lucky. Belt was barely a year old. The threads just came lose from the rubber. It wasn't a Hisun product but a 2013 CFmoto Uforce. But still same basic setup. 

 

 

[djl]

Hi Greg.  Thanks for the warning re: the belt.  Interestingly, the manual states that only the rollers should be greased and it doesn't mention that the sliders should be.  As a result I greased the rollers and not the sliders.  The sliders have hard plastic inserts that should slide (and wear) well against the dry sheave assembly grooves.  It specs 90g of grease to be used on the rollers, which is about a handful.  Like you, I felt this to be a bit excessive and used less.  Given the heat and centrifugal forces within the sheave, I will not be surprised if I find that the grease has been evenly distributed when I open it up next.  If I have to spend some money on sheave parts, I will be looking for a setup that will provide me a bit more speed.  There are aftermarket sheave kits that provide both lower and higher gearing.  😁