8DN Belt thoughts and results - Heat issues

[Lusemeat924]

Not so concerned about RPM's. It was my first ride with the kit. Bad Conditions, very soft. I also am running a Backcountry track. I will work on the RPM's.

My primary concern is the Temperature of the clutches and belt. Very hot. You could only hold your hand on either Clutch or Belt for 3 seconds and then ouch! Something isn't right. I do not suspect the primary clutch, I think the issue is in the Secondary?

Checked track. It is good.

Have you checked your belt alignment? I had to completely remove the shim behind secondary to achieve the 61mm suggested spec. I also found 1 bad primary clutch roller, the inner bushing walked out and was binding causing roller not to spin. I would think these 2 items were causing some of my heat issues. Our snow just all melted but will test as soon as I can to confirm.

 

[GlennM]

Man, all thiss fuss over this and that and the kitchen sink! What a waste of time and money ! My sled is bone stock, 3000 km on stock belt, goes like a rocket, I ain't touching a thing! Love the winder, best sled I've ever owned.

 

[Lusemeat924]

Man, all thiss fuss over this and that and the kitchen sink! What a waste of time and money ! My sled is bone stock, 3000 km on stock belt, goes like a rocket, I ain't touching a thing! Love the winder, best sled I've ever owned.

Well that is great to hear,,,, But a few of us are not so lucky forcing us to tweak and modify to find the ultimate solution to problems. Every sled seems to be a bit different out of the box and lots of guys are seeking more HP which obviously creates a new sting of problems and solutions.
This forum/threads, helps all of us navigate and distinguish problems that have occurred for our own needs,,,, and ones that are newly arising as more miles get put on these sleds. There are many talented and very smart individuals on this forum that offer great advice and help anytime when needed.
Not sure what your comment is about but it really offers nothing of value towards the thread,,,,, just my opinion. If my sled was running as good as yours, I wouldn't even be on this forum, lol

 

[yamaha06]

I will let you know how hot my clutches are whenever I get to ride it, I also have the 1.6" ice cobra track. Last year clutching was all stock with 8JP belt and I could hold my hand on the primary and secondary sheaves but they definitely felt hot but I could hold my hand on them for a while they were not warm like others have reported, and my clutch offset is good at 60.8mm. This year I am running Hurricane tune, STM primary weights with stock spring and glide washers, Thunder products 911 cover. Secondary has Thunder Products orange spring and a Dalton 33/35 Helix wrapped at 3/3 and also still running stock gearing. I will still be using the 8JP belt I guess and see how it goes, I will see how hot the clutches feel this year with the changes. I don't know what other belt to really run since it seems like 8DN is hard on the sheaves.

 

[GlennM]

Well that is great to hear,,,, But a few of us are not so lucky forcing us to tweak and modify to find the ultimate solution to problems. Every sled seems to be a bit different out of the box and lots of guys are seeking more HP which obviously creates a new sting of problems and solutions.
This forum/threads, helps all of us navigate and distinguish problems that have occurred for our own needs,,,, and ones that are newly arising as more miles get put on these sleds. There are many talented and very smart individuals on this forum that offer great advice and help anytime when needed.
Not sure what your comment is about but it really offers nothing of value towards the thread,,,,, just my opinion. If my sled was running as good as yours, I wouldn't even be on this forum, lol

Ya I understand your point. I didn't intend to offense anyone, but to me it seems that the more guys are doing this and that to their sleds seems to be causing more issues. Once again I'm sorry !

 

[Snowaddict]

View attachment 135874 View attachment 135874

Does this look normal?

Mine looks the same and was told that's ok.

 

[ClutchMaster]

These aren’t the droids we’re looking for....move along.

 

[XP123]

Normal spring rubbing Steveo, nothing to worry about.



Hard belts generally run cooler than soft belts, as long as the they are clutched properly. If you over clamp a sticky belt it will stick in the sheave fairly hard to pull it out. Well as your clutch rotates the belt must release itself from being wedged into the sheaves. A soft belt deforms and sticks in the sheave and as the clutch rotates to the point where it releases from the sheave it can cause a lot of friction as it try’s to exit the clutch. Multiply this friction by thousands of RPM and you will get hot clutches. This makes clutching more difficult with a softer belt. You really need to get your combination perfect to run a soft belt. A soft belt does have its advantages tho, when done right the belt is more flexible and takes less energy to rotate around the clutches, this can be more efficient than a hard stiff belt.
Advantages of a hard belt are better/quicker shifting characteristics namely upshift/backshifting, (nobody will argue that old school Yamaha’s had the best shifting clutches ever, not even cat guys! And they used the hardest belt ever an 8dn) also a more forgiving clutch setup and of course longevity.
I believe most manufacturers have gone To softer belts because that means they will sell more belts over the life of the sled. Also since most aftermarket belts are fairly hard, if you try to run an aftermarket belt it will usually slip causing premature failure. Therefore you are forced to run the factory belt. Just look at the performance oriented ski-doos, they went to soft belts back in 2001 and if you were to put a hard belt in these machines it was toast in no time.
As far as far as grooving the sheaves, yes over time hard belts wear the clutch faces but if clutched properly the should last the life of the sled. Look at the Apex, many have 15k miles on the original clutches still. Besides when they do get a groove in them you can use that as an excuse to machine them for overdrive.

Cheers, CM

You are the clutch master but I don't agree with a lot of what you posted. Do you really think the manufacturers went with softer belts so they can sell more of them? You say soft belts cause lots of friction then you say done right they take less energy to rotate around the clutches.. I'm not a clutch or belt expert but a lot of what you are saying goes against everything I have learned over the years. That's OK and I'm not saying you are wrong either. I like reading opinions from everybody and I learn stuff all the time. At this point I have yet to read anything about belts and belt life to make me believe any of it to be fact and give me a better option than the stock belt I'm running now. I will keep reading and listening to the options many have given. Thank you for you input and you knowledge.

 

[**sj**]

a lot of guys start messing with the cocktail ....like gearing and track...then wonder why they have issues..

for those who have blown belts...with everything in spec...look for evidence...like csi

are there skid marks under the belt guard?

is the clutch bay wet?

did your belt have cord pop and show you signs before hand?

what were you doing immediately before and during the failure?

 

[ClutchMaster]

You are the clutch master but I don't agree with a lot of what you posted. Do you really think the manufacturers went with softer belts so they can sell more of them? You say soft belts cause lots of friction then you say done right they take less energy to rotate around the clutches.. I'm not a clutch or belt expert but a lot of what you are saying goes against everything I have learned over the years. That's OK and I'm not saying you are wrong either. I like reading opinions from everybody and I learn stuff all the time. At this point I have yet to read anything about belts and belt life to make me believe any of it to be fact and give me a better option than the stock belt I'm running now. I will keep reading and listening to the options many have given. Thank you for you input and you knowledge.

Hey it’s all good bro glad you enjoy the read! As far as the soft belts being more efficient it’s a balancing act between how hard the belt is to bend around the sheaves and how much the belt sticks in the clutch. It bends much easier around the sheave so that makes it more efficient but you need to be careful of over tensioning the belt or it will stick and negate any efficiency gains. Bending a stiff belt at thousands of rpm results in efficiency loss that’s why they came up with top cog belts they bend easier.
I believe that the soft belts are more efficient theory came to be back when low torque 2 strokes used them a lot in drag racing. These big torque turbo sleds need a harder belt than those old high rpm low torque machines. Industry has gone the opposite way for some reason. I’m just guessing about the reasons as to why, and the only thing I can come up with is selling more belts.
The early 2000 ski-doo 800’s never could get over 1000 miles on a belt. If you put a Aftermarket belt on it was even worse. They blamed it on the huge torque. Well if you fix the clutches to provide more belt grab you can run the harder belts for over 2000 miles and the shallower helix angles provide much better backshift for trail riding.

 

[ClutchMaster]

Not sure what is going on with my clutches either. I installed the Thunder Products Orange Secondary spring which I believe is made by Dalton. My clutches are now super hot and the belt itself is hot. I can't keep my hands on it. Not sure what is the culprit but I am leaning towards the Secondary spring. I have it wrapped 3/3, I had a hard time to rotate it enough to install. Very Stiff. I may go back to the original spring and check the temperature. I run the Gates Carbon 8JP and it is making a lot of dust and I can smell it. I ran this same belt in my Viper with very little temperature or dust. My Sidewinder is not flashed either.

Did you ever try the 8dn belt?

 

[chaleurphantom]

Did you ever try the 8dn belt?

I did not. I have only tried the Gates 8JP so far. Its funny because NOSPRO released an update yesterday about the Orange Secondary spring. They were originally suggesting the Orange spring to be set at 3-3. When I installed the it at 3-3 it was very tight. I made a run with it at that and it wasn't working right. Very hot and burning belt rubber like crazy.

I took secondary apart and found the belt was only making about half travel down the sheave. I had made a line with a marker. It would appear the spring was too tight and holding back the Secondary from opening. I have no idea how the belt didn't blow.

I reset the spring at 2-3 and made a run yesterday. It worked very well. Temperature was reduced significantly, RPM'S were 8700 a little low. The only thing I noticed was the RPM'S never spiked? From my experience whenever you hit it, it is normal for RPM's to spike and then settle back, no? I tried a few times to check this but I only get linear acceleration. RPM's are a little low but I will fix that.

 

[ClutchMaster]

I did not. I have only tried the Gates 8JP so far. Its funny because NOSPRO released an update yesterday about the Orange Secondary spring. They were originally suggesting the Orange spring to be set at 3-3. When I installed the it at 3-3 it was very tight. I made a run with it at that and it wasn't working right. Very hot and burning belt rubber like crazy.

I took secondary apart and found the belt was only making about half travel down the sheave. I had made a line with a marker. It would appear the spring was too tight and holding back the Secondary from opening. I have no idea how the belt didn't blow.

I reset the spring at 2-3 and made a run yesterday. It worked very well. Temperature was reduced significantly, RPM'S were 8700 a little low. The only thing I noticed was the RPM'S never spiked? From my experience whenever you hit it, it is normal for RPM's to spike and then settle back, no? I tried a few times to check this but I only get linear acceleration. RPM's are a little low but I will fix that.

It’s s shame!

 

[chaleurphantom]

Well that doesn’t make a lot of sense? Your RPMs went up and you reduced your spring wrap? Are you sure you didn’t make any other changes? Reducing wrap usually reduces belt clamping force which in turn causes more slipping. But like I said before you were clamping that soft belt to hard, pretty positive with your setup it wasn’t slipping that Gates.

I guarantee it was slipping the Gates Belt. I had to clean up the dust. The excessive torsional force of the tight spring was not allowing the Secondary to open. The Primary was trying to ride up but the Secondary spring wouldn't allow the belt to ride down. Slip will have to occur. I also had a black streak on the Secondary mid way down.

 

[ClutchMaster]

Doughnuts anyone?