Just thought I would share a post made by Hunterworks.
"Viking Clutch System is HOT!!!
This information is a little aged and we have changed our sheave up since it was written but most of this still applies. If you have any concerns before buying please call me.
I will put red notes where things have changed
Our Viking Machined Sheave has been out for over a year now, nothing wrong with the product but what we found out over time causes us concern about the Viking and the use of our sheave.
Basic Viking Clutch Info:
Imagine taking a Grizzly 700, adding a front and rear rack to it then putting 1000lbs of corn on it. Do you think the clutch would be running hot on that? Yes of course it would, and that is more or less what a Viking is. The Viking for all intensive purposes has the same clutch as the Grizzly does and even shares several of the same parts including the wet clutch (Except for the 15 model). The Viking weighs almost 1000 more lbs than the Grizzly so before we ever get started, the clutch system runs hotter, then for whatever reason lots of people are running really large tires on the Viking in the 29" and larger tires which makes the clutch even hotter, then some are snorkeling it which again is hotter then they drive slow in high range which does not move enough air and even hotter.
How this affects our Sheave:
The people in this category have experienced flat spotted rollers from all the heat. We have over 3000 sheaves out there and over 37,000 greaseless weights out there with little to no issues in grizzlies and rhino's but this Viking with the above mentioned conditions can but not always flat spot the rollers which in turn makes the belt run too low in the primary and cut the belt on the bottom of it on the movable sheave side.
We went back to a stock belt so even if you flat spot a roller from heat, you should still be safe from it cutting the belt
We had our sheave out first, being first means you are the one taking the hits on things when it does not fit all applications and then you work through it to hopefully eliminate those issues then competitors are able to come behind you, see what happened to you and then maybe fix theirs before it ever comes out. But in our case I have heard recently they are running into the same issues. This is being ugly, well duh!!! This clutch is hot!!!!
People easily understand that if you put big tires on a vehicle, put a lift on it that you will break stock axles and it is not the axles fault it is what you have and what you are doing so you have no issue buying another axle and go on. So in this case, if you have the set of conditions mentioned above you might flat spot a set of rollers here and there, I will sell a repeat customer a set for a reduced price.
We have even changed brands of rollers to see if that helps, we will only know over time. No way to test this quickly.
How to prevent it:
One, don't use big tires!!! Anything over 28" is too much for this vehicle that is too heavy and has a weak engine for it's size but if you must use larger then, one run in low gear most all the time, you can use low up to about 40 mph with our sheave. Try not to run so slow or add in some higher speed runs to cool the clutch off. You can also install a inline bilge pump blower to force air in there. We don't sell them but they are available at a marine store and get a higher CFM one.
Yes we offer the set ups for the larger tires but they do have this affect on them.
Who we intended the Sheave for:
I really intended the sheave for people with 27" tires and smaller who were concerned about higher top speeds, lower cruising RPM, wanted to go greaseless and better take off and also do not run around really slow. It does however really help to get the really large tires going though. This group of people who have our sheave are not experiencing any issues.
We believe in setting expectations so no one gets a surprise later. Sometimes you won't know things until it gets out in customers hands and what they are putting it through. Same thing with the manufacturers of these vehicles, they think they got it and we tear it up, then they make it better.
Does any of this mean you should not buy it? No it still works as it should and still does exactly what we say it does. It is just under the right conditions in this vehicle the rollers can flat spot. I said can, not will.
Just want this information out there before you buy so you know what to expect from our Machined Sheave on a Viking!!