I have Been told that you should never use brake clean or products like that on your clutches. Only soapy water. The reason I was given was that the chemicals soak into the metal and then release when the clutches get hot and cause the belt to slip. I don't know if this helps but it is something that I have heard could cause problems.
Nytro belt issues please help
- Thread starter justinkredible56
- Start date
The brake clean is used because it is "supposed" to not leave any residue at all. Regardless, you may be onto something and I appreciate your comment.
As M5 said you are way off.
I would try something close to the Apex setup because you are similar in HP and track size. That pipe does add some HP but not much. If your at 145 HP i would be surprised. Do you still have your stock weights ? They should be 8FS-00 unloaded.
The stock Nytro MTX is as follows
8FS-00 unloaded (65.5 grams)
G-W-G primary spring
16.5 rollers
39 helix
pink sec spring @ 70degrees
20/40 gearing
As you said the stock setup did not do you any favors. Most likely because you are in the 300lb range and you have a power increase.
I'm gonna leave the AC yellow out of this to make it simple.
If you were to go to a white spring @70 degrees it would be stiffer than the stock pink. Now because you went to the white spring (or AC Yellow) you will now need to increase the weight in the primary. I would say a couple of rivets would get you in the ball park. Now with the 8FS almost loaded (70.9 grams)with the white spring you are very similar to the Apex setup other than the helix and primary spring according to the TY clutch info. The 8FS weights are kind of square. You could buy a set of adjustable primary weights which would be convenient and will cost a little.
The primary G-W-G (stock) is the stiffest primary spring. M5 most likely either ran this one or a B-W-B which is a little softer than the G-W-G. Stock Apex has the yellow pink yellow primary with a 45 helix. The Y-P-Y spring is similar to the B-W-B force wise.
If it were me i would stick with the Y-P-Y primary because you have it already (or B-W-B) and 39 helix and throw some more weight at the primary. Your Hartmen weights are no good IMO (way to light as per your pics). Either add 2 rivets to the 8FS or or find something adjustable like Daltons QAY-62 adjustables. They say a Apex is in the Dalton 64-68 gram range stock.
If you want to keep it cheap try the stock 8FS loaded more (bigger pain dealing with rivets) but cheap.
My setup would look like this to start:
8FS-00 two 13.3 rivets in outer and center or Dalton adjustables
14.5 rollers
Y-P-Y spring (or B-W-B slightly stiffer)
39 helix
AC yellow spring @10 degrees (to start)
19/40 gearing
Just by looking at this it is very close to the Apex stock clutch setup minus the 45 helix. Also it is close to M5 setup he had on his Nytro which was very similar to your machine. The big difference is the weight profile (between his and yours). The weight will change between the 8FS and the Dalton adjustables due to the profile. You will have to decide on that for yourself.
Others can feel free to chime in and add to the confusion LOL. I'm sure something close to this will get you in the ball park.
The 8DN are way too light as you can tell just by looking at the pics. If you were to just add more weight to your setup it would improve but the secondary spring (your current spring) would be too light i think eventually once you get the primary close because of the weight and power thing.
I hope this helps. Clutching can be frustrating!
I would try something close to the Apex setup because you are similar in HP and track size. That pipe does add some HP but not much. If your at 145 HP i would be surprised. Do you still have your stock weights ? They should be 8FS-00 unloaded.
The stock Nytro MTX is as follows
8FS-00 unloaded (65.5 grams)
G-W-G primary spring
16.5 rollers
39 helix
pink sec spring @ 70degrees
20/40 gearing
As you said the stock setup did not do you any favors. Most likely because you are in the 300lb range and you have a power increase.
I'm gonna leave the AC yellow out of this to make it simple.
If you were to go to a white spring @70 degrees it would be stiffer than the stock pink. Now because you went to the white spring (or AC Yellow) you will now need to increase the weight in the primary. I would say a couple of rivets would get you in the ball park. Now with the 8FS almost loaded (70.9 grams)with the white spring you are very similar to the Apex setup other than the helix and primary spring according to the TY clutch info. The 8FS weights are kind of square. You could buy a set of adjustable primary weights which would be convenient and will cost a little.
The primary G-W-G (stock) is the stiffest primary spring. M5 most likely either ran this one or a B-W-B which is a little softer than the G-W-G. Stock Apex has the yellow pink yellow primary with a 45 helix. The Y-P-Y spring is similar to the B-W-B force wise.
If it were me i would stick with the Y-P-Y primary because you have it already (or B-W-B) and 39 helix and throw some more weight at the primary. Your Hartmen weights are no good IMO (way to light as per your pics). Either add 2 rivets to the 8FS or or find something adjustable like Daltons QAY-62 adjustables. They say a Apex is in the Dalton 64-68 gram range stock.
If you want to keep it cheap try the stock 8FS loaded more (bigger pain dealing with rivets) but cheap.
My setup would look like this to start:
8FS-00 two 13.3 rivets in outer and center or Dalton adjustables
14.5 rollers
Y-P-Y spring (or B-W-B slightly stiffer)
39 helix
AC yellow spring @10 degrees (to start)
19/40 gearing
Just by looking at this it is very close to the Apex stock clutch setup minus the 45 helix. Also it is close to M5 setup he had on his Nytro which was very similar to your machine. The big difference is the weight profile (between his and yours). The weight will change between the 8FS and the Dalton adjustables due to the profile. You will have to decide on that for yourself.
Others can feel free to chime in and add to the confusion LOL. I'm sure something close to this will get you in the ball park.
The 8DN are way too light as you can tell just by looking at the pics. If you were to just add more weight to your setup it would improve but the secondary spring (your current spring) would be too light i think eventually once you get the primary close because of the weight and power thing.
I hope this helps. Clutching can be frustrating!
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Hey Summitboy I really appreciate your help and comments. Clutching is very frustrating and at the beginning of all of this mess I had literally no idea how any of it worked, let alone how to even adjust it. But I love knowing HOW things work so input from the people who have helped me on this post have made muddy water slightly clear. Now I can clean and adjust my clutches by myself where as I wouldn't dream of messing with them at the beginning of this year.
I talked to Tom Hartman today again about my problems. We are stumped as to why his kit that is custom designed for my setup and weight is failing to produce good results. His customer service is top notch and he is going to work with me on sending back the clutch kit and going back to stock. I am however, per yours and M5's recommendations going to keep the 14.5 rollers.
This is the setup I'm going to try (Correct it if you see anything wrong):
GWG primary spring, because I have it and I have to send the YPY back to Tom.
14.5 rollers
Stock weights-adjusted to provide the appropriate RPM's
AC yellow secondary spring, initially wound at 10*
Stock 39* helix
Now my question is with this setup do you think it would be wise to drop another tooth in the chaincase and go with the 18/40 combo or stick with the 19/40. I ask because I have an opportunity to trade my 19 for a 18. I am by no means a lake racer, I'm a powder hound and love uphill boondocking along with highmarking. Top speed is not my concern but high track speed in a long pull IS.
Also does the profile of the Dalton/heavy hitter weights provide their worth in performance or is it more for ease of adjustability? If they are worth the money then I will invest in a set but if it's purely an adjustability thing I have no problem spending 5 minutes of my time and throwing different rivets in and pocketing $250.
Any suggestions welcome, and again I thank everyone for their help and input on my issue.
-Justin
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I'd try it with the 19 first because the 18 will drop your track speed which in the end is what you are after. If the setup just won't pull the 19 with your weight (it wil hunt up and down at WOT if this happens ie shifting down then back up just like a weak a$$ truck pulling a trailer up a hill) then yes you will need to go to the 18. Yamaha used the 18 in 2010 stock but I've never given their clutching much credit.
M5
M5
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I would try the 8FS loaded up a little. Its cheaper to start. It will be a pain the azz to put rivets in and out though and then the rivets will be junk after you take them out. If you look on Totally Yamaha there is a tech section that shows all the clutching components individually and can be useful when trying to figure out weights etc.
Try the G-W-G but you might want to soften it up a bit or you may need even more weight. I would try the Y-P-Y spring before you send it back and then it is just one more combo you have tried and it will cost you nothing. My choice would be the B-W-B for a final LOL
The Dalton weights are convenient, but pricey. The profile between the stocker and the Dalton is huge. The weight difference between the two will be different because of the profile. For example a stock Apex 8FS-00 partially loaded with 13.3 rivets in center and tip weighs 71ish grams. A Dalton will come in the 66isg gram weights and more or less do the same job with different acceleration etc. The 8FS-00 is like a flat profile where as the Dalton would be more curved for example.
Leave the gearing alone for now. You have already changed it to a 19. I think you should leave it constant for now and get the clutching figured.
Try the G-W-G but you might want to soften it up a bit or you may need even more weight. I would try the Y-P-Y spring before you send it back and then it is just one more combo you have tried and it will cost you nothing. My choice would be the B-W-B for a final LOL
The Dalton weights are convenient, but pricey. The profile between the stocker and the Dalton is huge. The weight difference between the two will be different because of the profile. For example a stock Apex 8FS-00 partially loaded with 13.3 rivets in center and tip weighs 71ish grams. A Dalton will come in the 66isg gram weights and more or less do the same job with different acceleration etc. The 8FS-00 is like a flat profile where as the Dalton would be more curved for example.
Leave the gearing alone for now. You have already changed it to a 19. I think you should leave it constant for now and get the clutching figured.
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I would gear it down to a 18. Right now your geared for 84mph, the 18 will drop you to 79. On a stock nytro in the mountains your never going to see these track speeds, so there's no point of running the 19 and the 18 will be easier on belts.
Although Franklin is correct there is some argument out there that the small 18 tooth gears are harder on chains. The 2010 Nytro comes with 18 stock now. If you want to go 18 thats fine but i would wait until you get the clutching to the point where your not cooking belts. JMO
All the clutching info is excellent.
But for some reason, I think it's something else. Heck, I've towed sleds out and never had a clutch/belt problem. That certainly accounts for your weight. Unless you are WAY WAY off in the clutching, or they just shot. It may be something else. I can't wrap my brain around it.
Do you feel drag? Out of the dirt bike world, if you have water in your brake fluid , it will heat up and boil applying the brake.
But for some reason, I think it's something else. Heck, I've towed sleds out and never had a clutch/belt problem. That certainly accounts for your weight. Unless you are WAY WAY off in the clutching, or they just shot. It may be something else. I can't wrap my brain around it.
Do you feel drag? Out of the dirt bike world, if you have water in your brake fluid , it will heat up and boil applying the brake.
You might be onto something there because I have already run through a set of brake pads. I was coming down the mountain one day, not using the brakes a lot due to engine braking and I lost my brakes completely. One of the pad rivets actually came out due to high heat. The only thing that would contradict it would be my RPM's are consistent and I haven't touched anything brake related. Owning a brand new sled for less than a year I would hope I don't have brake related failures already.
If my new setup doesn't work I'll definitely take a look at it.
Ya it's crazy to think that stock setups are around 70g and my weights were around 46-7g. I got a few of my springs today and installed everything.
Setup as I sit right now:
GWG primary spring
stock weights-I'll have to see what I need to do for adding rivet weight
15.6mm rollers--the stock ones
(sending the 14.5 rollers back with the kit in case they were bad to begin with)
AC yellow spring at 10*
stock 39* helix
19/40 gearing
I have a brand new belt that I ran through the dishwasher and clean clutches. I will be breaking everything in tomorrow and seeing how it does.
I have a BWB primary spring on order and will give it a shot.
All of my duct tape has been pulled off and now the only thing I have in place is a coarse screen door material over the stock vents. I think they were too open to begin with especially being on the clutch side.
Again I appreciate all the input and will definitely report back with results so future members can refer to it if they are having issues.
-Justin
The YPY spring doesn't seem to be a YPY, I'm not sure what it is...but here's a picture.
I was talked out of trying the 14.5 rollers last night when I picked up my AC secondary spring by my yamaha dealer, but with how easy it is to switch them I might as well give them a shot.
My dealer also said he would try and get 3 belts warrantied for me...this would be music to my ears if it actually happened.
Thanks again,
-Justin
N
NM
Well-known member
I think you are on the right track with the clutching you are going to try, but I think your track is way to loose. A loose track is not a fast track because it will not follow the intended path and be flopping around and maybe even be coming in contact with the front cooler. Set it at least to factory spec which is around 1-1.5 inches of rail clearance at 22 lbs pulling force. Our turbo sleds are probably even tighter than that.
You may look into it anyway, I have an apex with ~4500 miles, still on the original pads. Stock yam belts slip like crazy, if the brake is applying pressure, they may slip even more (which is why you might be toasting them). It might also account for your loss in track speed, while keeping RPMs where they should be.
You may just change the brake fluid just because. Shouldn't take but a few minutes. Even less time if you back bleed it. Just a thought. And it's also a lot cheaper than belts and clutching.
ETA:
Stolen from the overheating brake thread.
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L
Linc
Active member
The 8DN weights are too light, the Dalton is an excellent choice, they have the adjustable ones now that you can tune on the hill quicker. You need the the weight of the ramps to close the primary so you can shift out the secondary. If your secondary spring is too stiff, the primary can't close up and then it slips, you can see this on your photo's, the black mark near the top of your shift out on the primary matches the black mark in the middle of your secondary. Once the clutching gets there, the weights stall out against the stiff secondary spring and then the motor is left to try and get more by slipping instead of shifting, then it builds heat and deteriorates the belt. There is a book by Olav AAen called "Clutching Made Simple" an excellent book to understand what is happening. Next to the drive chain, your clutching is the most important detail for getting power to the ground, because all the power in the world won't mend a broken chain or and blown belt.
Get some Dalton adjustable weights, about 60- 66 grams, use the primary springs you have, they are a good start, get a Cat Yellow secondary, you already have the 14.5 rollers, take your extra helixes and secondary springs too, keep your 19 tooth ( one thing at a time ). Clean your clutch surfaces with scotch brite, do not use brake clean or any other cleaners, the chemicals in the cleaners can destroy the bushings on the sliding sheaves, use warm water with a mild soap if you need to. Find a consistent hill that is a 30- 40 degree slope on some fresh snow, not too deep, that you can move across with each run and change one thing at a time, take a magic marker with you and put a thick line on the face of the sheave, mark it with a number 1, go for a run up the hill carefully watching your track speed and RPM, return to bottom and mark it down in a note book, check your belt heat as well, if you're too low in rpm, typically you would lower the ramp weight, however keep in mind that if your RPM goes up and the speed goes down, it's slipping. Put a black stripe on your primary again, mark it with a 2 and do a run again, if there is less or more of the black mark showing this will tell you which direction to go your clutching, keeping in mind to watch your track speed and your RPM, this is your "Dyno". I've spent a whole afternoon, just dialling in the clutching sometimes.
There is some great advise on here, but not all clutching works the same, different weather, snow, rider weight and riding style all play a factor into setting up your clutching, so getting your clutching to work for "you" is something really only "you" can nail down perfect, but you need the tools and understanding first, just remember to change "ONLY ONE THING AT A TIME" and get Olav's book. The Yamaha belts are the best out there, but even they can only stand so much heat.
I hope this helps.
Linc
Get some Dalton adjustable weights, about 60- 66 grams, use the primary springs you have, they are a good start, get a Cat Yellow secondary, you already have the 14.5 rollers, take your extra helixes and secondary springs too, keep your 19 tooth ( one thing at a time ). Clean your clutch surfaces with scotch brite, do not use brake clean or any other cleaners, the chemicals in the cleaners can destroy the bushings on the sliding sheaves, use warm water with a mild soap if you need to. Find a consistent hill that is a 30- 40 degree slope on some fresh snow, not too deep, that you can move across with each run and change one thing at a time, take a magic marker with you and put a thick line on the face of the sheave, mark it with a number 1, go for a run up the hill carefully watching your track speed and RPM, return to bottom and mark it down in a note book, check your belt heat as well, if you're too low in rpm, typically you would lower the ramp weight, however keep in mind that if your RPM goes up and the speed goes down, it's slipping. Put a black stripe on your primary again, mark it with a 2 and do a run again, if there is less or more of the black mark showing this will tell you which direction to go your clutching, keeping in mind to watch your track speed and your RPM, this is your "Dyno". I've spent a whole afternoon, just dialling in the clutching sometimes.
There is some great advise on here, but not all clutching works the same, different weather, snow, rider weight and riding style all play a factor into setting up your clutching, so getting your clutching to work for "you" is something really only "you" can nail down perfect, but you need the tools and understanding first, just remember to change "ONLY ONE THING AT A TIME" and get Olav's book. The Yamaha belts are the best out there, but even they can only stand so much heat.
I hope this helps.
Linc
I've read the PDF version of Olav's book and that's the only reason I know anything about how this "mysterious" clutching works. I keep thinking I should order it and re-read it several times but have yet to do so. Thanks for the great information!
Last night I spent 2.5-3 hours breaking in another new belt. Altering RPM's constantly and not putting too much load on it. In other words, back and forth runs on flat ground going in and out of the throttle slowly and controlled. I'm determined to make this single belt last the rest of the season.
The setup I'm testing right now:
GWG primary
stock weights-they have rivets in each hole already but I'm not sure how much total weight is.
15.6 rollers and tried the 14.5 in the same environment.
AC Yellow secondary
Stock 39* helix.
19/40 gearing
What I'm noticing right now:
Rpm's are low...I'm sitting around 8100 rpm's at full throttle on flat ground and packed snow slowly picking up speed. I will buy a digital scale and adjust the weights. I want to peak at 8600 rpm on a deep powder pull but I can't do that until I get my belt broken in.
14.5 rollers vs. 15.6 rollers- The 15.6's engagement speed was about 3400rpm and the 14.5 was around 3200. I started the day with the 15.6's and switched to the 14.5's half through and noticed that I get a boost in acceleration. Well at least it feels like the bars want to jerk out of my hands more so than the 15.6's. The 15.6's feels more like a Cadilac, fast but smooth. The 14.5's feel like a drag car, they have more of a headstrong feel.
When I swapped the weights I took a look at my primary sheave and the belt is riding a LOT higher in the primary than before so I feel like I'm getting close. I'm hesitant to lower the overall weight from my weights to reach peak RPM's before I give the BWB primary spring a try. I don't know that it will make THAT much of a difference in peak rpm but I want to see what happens with a different spring rather than chase rpm's twice.
I will invest in some Dalton's over the summer but right now with school/books/housing/truck payment they aren't in the budget.
The sled feels a lot better now, it has a torque feel that was missing before. Enough typing I'm off to break in the belt some more! Thanks for all of the helpful posts!
-Justin
