Hardcore Sledder banner

1 - 20 of 26 Posts

·
Registered
2021 RR, 2019 Alpha
Joined
·
174 Posts
Discussion Starter #1
cliff notes: skip to last paragraph with questions.

Put 400 miles on the new 2021 8000rr last weekend after fixing a bunch of dealer prep / factory blemishes. Was disappointed with the sled’s initial build and set up. Riding it definitely put a smile on my face, tho. It seems to do just about everything better than my ‘16 Limited but usually topped out around 101mph on fresh groomed trails.

One thing I need to address are the clutch weights. I was very happy with initial response, backshift, and acceleration to ~90mph. If I squeeze the throttle to the bar I usually see 8200-8300rpm immediately. I didn’t watch the tach the entire time but I did see 8350rpm once. Tach is very steady but climbs a little bit around 100mph. From the dyno reports I read by dynotech, it seems the 2020 & 2021 800s make power sooner than the 2018-2019s because of the extra compression. Power appears to fall off rapidly after 8,000rpm (so that is what I want to clutch for).

I‘ve never clutched a sled before so this is where I need your input. It seems I need heavier clutch weights. I’ve spent half a day searching this forum and reading reviews because (I overthink stuff) I want to do this right. Sled has to be reliable as I sometimes take backpacking trips in the middle of nowhere late at night.

So which clutch weights would you guys recommend? Is there a brand you’ve put a lot of miles on without flat spotting or having the magnets come apart? Any brand you’ve used that lost performance? I’ve been leaning toward Cutler, Thunder, or SSI...

Thanks for reading and any info is appreciated!
 

·
Registered
Joined
·
16 Posts
https://bikemanperformance.com/bmp-goldstar-adjustable-arctic-cat-clutch-weights.html I run these in my 800 zuk and they are great, i dont know much about the new sleds but I find it easier to pull the entire clutch to change the weights. I really enjoy throwing the magnets in different holes and seeing how it affects my riding, but it takes me about 30-45 minutes to pull the clutch off, disassemble the clutch then move the weights but I dont mind. Its like changing jetting with a few more steps. If you go to the shop in person they might just give them to ya at cost ;)
 

·
Registered
2020 ThunderCat, 2017 ZR 6000 RS
Joined
·
1,221 Posts
cliff notes: skip to last paragraph with questions.

Put 400 miles on the new 2021 8000rr last weekend after fixing a bunch of dealer prep / factory blemishes. Was disappointed with the sled’s initial build and set up. Riding it definitely put a smile on my face, tho. It seems to do just about everything better than my ‘16 Limited but usually topped out around 101mph on fresh groomed trails.

One thing I need to address are the clutch weights. I was very happy with initial response, backshift, and acceleration to ~90mph. If I squeeze the throttle to the bar I usually see 8200-8300rpm immediately. I didn’t watch the tach the entire time but I did see 8350rpm once. Tach is very steady but climbs a little bit around 100mph. From the dyno reports I read by dynotech, it seems the 2020 & 2021 800s make power sooner than the 2018-2019s because of the extra compression. Power appears to fall off rapidly after 8,000rpm (so that is what I want to clutch for).

I‘ve never clutched a sled before so this is where I need your input. It seems I need heavier clutch weights. I’ve spent half a day searching this forum and reading reviews because (I overthink stuff) I want to do this right. Sled has to be reliable as I sometimes take backpacking trips in the middle of nowhere late at night.

So which clutch weights would you guys recommend? Is there a brand you’ve put a lot of miles on without flat spotting or having the magnets come apart? Any brand you’ve used that lost performance? I’ve been leaning toward Cutler, Thunder, or SSI...

Thanks for reading and any info is appreciated!
I would call TOMCATPERFOMANCE and ask him, he is very knowledgeable with what works on the new 8000.
 

·
Registered
Joined
·
87 Posts
Another possible (and quicker, cheaper) option would be to change the primary spring for one with a slightly lower finish rate. Just a thought...
 

·
Registered
Joined
·
2,904 Posts
My 21 RR is doing the same thing. Seems odd because the 20 ZR acts fairly normal on top. The only real difference seems to be the helix. The 20 says 64/49 and the 21 states 56/49. I didn't pull the 20 to verify, but the 21 matches the sheets. Both have the same springs and weights.
I like to get them close and change primary springs as suggested. Super easy to do right on the trail and cheap. Going with what I see for rpms, it would take a smaller finish rate. Stock is 120/265 and it works fairly well on the bottom. The 21 starts giving up with over rev on top. Bad, in my opinion. Back out of it over 70, and try getting it to pull. It's a real turd.
I usually like to break them in before swapping anything. I ran this thing for 560 miles at pure stock.
Clutch faces before cleaning the sheaves. You can really see where the shifting gave up, but no big hot spots.
PXL_20210104_213315570.jpg
Secondary actually looked better than normal inside.
PXL_20210104_215907610.jpg
It had the basic flaking, but very little dust. The spring rub was better than many I've seen.
I did throw some delrins in for the heck of it, but I don't know if they are needed. I figure they can't hurt the back shift and add a few pounds of pressure.
I have a pile of primary springs to try. Oddly enough, I had to pick up a few with lower finish. My stash was oddly filled with springs that had higher pressures.:unsure: I don't normally have to tame down the rpms.
 

·
Registered
2021 RR, 2019 Alpha
Joined
·
174 Posts
Discussion Starter #7
I really liked the idea of a primary spring with a softer finish rate and thought I found a good spring... Then I found that most companies rate their springs at different compressed heights 🤦. I’m ordering a small variety of primary springs and the dalton weights. Wish me luck.
 

·
Registered
Joined
·
85 Posts
I also put my first 200 miles on 2021 RR and sled actually hits the rev limiter at 8400 easily. Love the way the sled rides and handles but clutching is way off. The one other thing I noticed is it hangs at 2200ish rpm idle for a long time then settles down to normal idle speed compared to 2018. Its kind of annoying but figure it is to reduce flames. My 18 is a flame thrower. I will get the sled through break in and then do some clutching.
 

·
Registered
Joined
·
1,594 Posts
I also put my first 200 miles on 2021 RR and sled actually hits the rev limiter at 8400 easily. Love the way the sled rides and handles but clutching is way off. The one other thing I noticed is it hangs at 2200ish rpm idle for a long time then settles down to normal idle speed compared to 2018. Its kind of annoying but figure it is to reduce flames. My 18 is a flame thrower. I will get the sled through break in and then do some clutching.
Let it idle. Pull your gloves and take your helmet off before you shut it down. Both my 600's hang a bit, maybe 30 seconds max. Used to it now. It is done to cool the engine and to burn off any excess fuel for emission reasons.
 

·
Registered
Joined
·
1,946 Posts
Im almost betting they shimmed the clutch more on the 21s. The drive spring is the same, the finish angle on the helix is the same, these clutchs have a tendency to run high rpm at slow speeds which i feel is due to the weight not wanting to shift. Its getting hung up on its access.

My 18 does this and installing a 16 clutch that had about .008 more weight to roller clearance dramatically helped cure this.

The 17s had a lot of shimming, and ran heavy weights stock (74 vs 72 in 16, 18,19. ) the 2020+ had stiffer secondary and primary spring rates. And run 74s again.

Favoritos you should check your 2020 and 2021 roller to weight clearance and see if they differ.
.the 2020s ran pretty close to right on so it tells me shimming or more power on 2021. And i dont believe its more power
 

·
Registered
Joined
·
1,946 Posts
I think vforce rubber tipped petals cures the idle. My 18 idled high too. After reeds its 1550 and drops right down to it. Actually lower for a second
 

·
Registered
2021 RR, 2019 Alpha
Joined
·
174 Posts
Discussion Starter #13
Hey guys, thanks for all of the replies! Sounds like I’m not the only one looking for more. I ordered a small assortment of primary springs and adjustable weights. I’m only going to make one change at a time and plan to start with the purple/white venom spring (120/240) this weekend. It would be great if that’s all it takes to get it just under 8000rpm. I also ordered some adjustable weights in case I need to tune it further. Heavier weights would possibly mean higher spring rates are required, right?

Mine idles down pretty fast if I’m riding tight trails. When I get on railroad grades I can come to a stop, wait 30 seconds, remove helmets and gloves, get off sled, empty my bladder, walk back to sled, count the stars and it will still be idling at 2600rpm (okay, maybe not count the stars).

Where would I be looking for clutch shims, Procross? Behind the secondary? Could it have something to do with the new TCL?
 

·
Registered
Joined
·
7,208 Posts
My 21 RR is doing the same thing. Seems odd because the 20 ZR acts fairly normal on top. The only real difference seems to be the helix. The 20 says 64/49 and the 21 states 56/49. I didn't pull the 20 to verify, but the 21 matches the sheets. Both have the same springs and weights.
I like to get them close and change primary springs as suggested. Super easy to do right on the trail and cheap. Going with what I see for rpms, it would take a smaller finish rate. Stock is 120/265 and it works fairly well on the bottom. The 21 starts giving up with over rev on top. Bad, in my opinion. Back out of it over 70, and try getting it to pull. It's a real turd.
I usually like to break them in before swapping anything. I ran this thing for 560 miles at pure stock.
Clutch faces before cleaning the sheaves. You can really see where the shifting gave up, but no big hot spots.
View attachment 2115501
Secondary actually looked better than normal inside.
View attachment 2115502
It had the basic flaking, but very little dust. The spring rub was better than many I've seen.
I did throw some delrins in for the heck of it, but I don't know if they are needed. I figure they can't hurt the back shift and add a few pounds of pressure.
I have a pile of primary springs to try. Oddly enough, I had to pick up a few with lower finish. My stash was oddly filled with springs that had higher pressures.:unsure: I don't normally have to tame down the rpms.
Interesting, my 20 rr had 56-49-20 ER 13. I didn’t check the helix on 21’s but will pull after this weekends ride. Remember being concerned about over rev last winter and it ended up being pretty much perfect at ~1,000 miles. Would peak to 8,100 and pull down to 8,000. Hope we can keep a dialogue going as miles are added.
 

·
Registered
Joined
·
2,904 Posts
Im almost betting they shimmed the clutch more on the 21s. The drive spring is the same, the finish angle on the helix is the same, these clutchs have a tendency to run high rpm at slow speeds which i feel is due to the weight not wanting to shift. Its getting hung up on its access.

My 18 does this and installing a 16 clutch that had about .008 more weight to roller clearance dramatically helped cure this.

The 17s had a lot of shimming, and ran heavy weights stock (74 vs 72 in 16, 18,19. ) the 2020+ had stiffer secondary and primary spring rates. And run 74s again.

Favoritos you should check your 2020 and 2021 roller to weight clearance and see if they differ.
.the 2020s ran pretty close to right on so it tells me shimming or more power on 2021. And i dont believe its more power
I checked the roller to weight clearance on the stock 21 clutch. It is .105 clearance. My 20 is sitting up north, so I haven't checked that yet. I checked my backup clutch too. It is .037 clearance. I'm not sure if I can do a fair comparison between the two. I had them throw on a cover when it was balanced. The shimming was done during that process.

Maybe someone can verify what their clearance is on the stock 20 clutch?
 

·
Registered
Joined
·
1,946 Posts
.037 is what my 18 is. My 16 is .044

I think being the 21s are shimmed that much is a big reason they really rev. Plus it takes more weight to pull the rpm down.

My 17 was shimmed large like that. Engaged low (3200) with stock spring (105-255). It was better with the 130/250 venom purple/red. The rollers actually went to end of weight but the 17s had issues with good top end. I think shimming around. .045-.055 is the way to go.

With less shimming the tip weight really makes a diff being the roller doesnt shift all the way to the end and it acts like mondo leverage at the tip.

The 17s and sounds like 21 shimming will let that roller go to the tip of the weight so you will need major tip weight to make a difference i feel.
 

·
Registered
Joined
·
138 Posts
The clearance on my '20 ZR 8 is .026 with stock weights, and that is snug. I can't remember exactly why my engagement RPM is, but I want to say low 3's.
 
1 - 20 of 26 Posts
Top