2016 m8000 3” worth getting 21/49 gearing setup?

[COLBEE]

Had a 14 HCR that I tried that on, ran the 3” with 8T drivers and 19/50 gearing, in heavy snow it was terrible for clearance and packed in too much and made a horrible rubbing sound pretty much steady. Changed to 7t with the 21/49 hyvo kit and manual tensioner and was way more better, also was running 70 gram weights with a stage 2 speedwerx kit and with all that set up it had lots of track speed and still lots on the bottom

Thanks for for the info, I think the 21/49 gearing with 70g weights is the way I’m going to go for now, I might also do the manual tensioner.

 

[Jorgy]

Thanks for for the info, I think the 21/49 gearing with 70g weights is the way I’m going to go for now, I might also do the manual tensioner.

I'm doing the same setup. Mainly cause I'm feeling lazy and don't want to pull the skid on on this sled.

To someone's point above though, I ran a 3" track on my 15 pro with 7 tooth drivers and the clearance to the bulkhead was 3/16". Only in heavy wet snow would I hear ice/snow grind through the bulkhead, never any issue and no damage in 2000 miles. Clearance is not an issue as long as you run proper track tension

 

[tmo1620]

I'm doing the same setup. Mainly cause I'm feeling lazy and don't want to pull the skid on on this sled.

To someone's point above though, I ran a 3" track on my 15 pro with 7 tooth drivers and the clearance to the bulkhead was 3/16". Only in heavy wet snow would I hear ice/snow grind through the bulkhead, never any issue and no damage in 2000 miles. Clearance is not an issue as long as you run proper track tension

May not cause damage but is annoying as hell and where there is restriction there is a slight loss of power, especially when you have to run your track tension a touch on the tighter side because of the lack of clearance. I usually like to run my track a touch on the loose side. When I had the 3” with 8T drivers I had about 1/8-3/16” and that was to little space for me to be comfortable with, and I had to run tension tighter than I like

 

[Jorgy]

May not cause damage but is annoying as hell and where there is restriction there is a slight loss of power, especially when you have to run your track tension a touch on the tighter side because of the lack of clearance. I usually like to run my track a touch on the loose side. When I had the 3” with 8T drivers I had about 1/8-3/16” and that was to little space for me to be comfortable with, and I had to run tension tighter than I like

It only happens after you stop for a little while and you get snow turning to ice build up. So it's gone in the first rotation of the track. I think the small flaws are worth the benefit, but yes ensuing proper track tension is key. I've never had to run tighter than the manual spec though

 

[Clode]

I have the 8tooth drivers and they work great. I run manfacturer spec track tension with no issues.

 

[tmo1620]

It only happens after you stop for a little while and you get snow turning to ice build up. So it's gone in the first rotation of the track. I think the small flaws are worth the benefit, but yes ensuing proper track tension is key. I've never had to run tighter than the manual spec though

It made noise constantly not just after a stop and freeze up, not as much when it was cold and snow was light but in the spring it was brutal, the sled performed better with the higher gearing and 7t anyway and was a cheap swap over

 

[PNWsledman]

I have a 2016 M8000 Ltd 162 3” I bought last year. I rode it for the season but found it to be geared too low. I know d/r and 8 tooth drivers would be best but not interested in spending the cash. I have been looking at the bdx 21/49 set up. Just wondering if anyone has used this kit and if it works well? Quality? Is the 21/49 ratio the way to go? i know cat has changed the material the gears are made of year to year and want to make sure this is going to hold up.

Dont want to revive an old thread but what did you end up going with and how did it work out? Riding the same sled this year and curious what to do to it

 

[Teth-Air]

Dont want to revive an old thread but what did you end up going with and how did it work out? Riding the same sled this year and curious what to do to it

Guys that think any mountain sleds needing to be geared up should try clutching first as gearing up is a bad band-aid for loading a motor. Lighter clutch spring(s) or more clutch weight has more gains as you will not have the belt ride low in the primary all the time. The belt being low in the primary where there is minimal contact area will allow excessive belt heat due to slippage.

 

[tmo1620]

Guys that think any mountain sleds needing to be geared up should try clutching first as gearing up is a bad band-aid for loading a motor. Lighter clutch spring(s) or more clutch weight has more gains as you will not have the belt ride low in the primary all the time. The belt being low in the primary where there is minimal contact area will allow excessive belt heat due to slippage.

I had a ton of cat sleds and have tried just about everything you can think of on them. The higher gearing worked great for me and I’ve never blown one belt on a 2 stroke cat in my life. I also was doing clutching but the cats like 21/49 gearing


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[Teth-Air]

I had a ton of cat sleds and have tried just about everything you can think of on them. The higher gearing worked great for me and I’ve never blown one belt on a 2 stroke cat in my life. I also was doing clutching but the cats like 21/49 gearing


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Maybe there are other reasons you liked it rather than going 80+ miles per hour? Maybe less agressive feel with slower shifting and less buzzy feel? I don't say you didn't like like it more but ask what felt better?

 

[lilduke]

I know its fun buying sled parts, but Id at least try riding it a couple times before I did any thing.

 

[tmo1620]

Maybe there are other reasons you liked it rather than going 80+ miles per hour? Maybe less agressive feel with slower shifting and less buzzy feel? I don't say you didn't like like it more but ask what felt better?

I always felt like it had more track speed in it and was just making more noise with more throttle and not picking up speed with the stock gearing and over revs from time to time by about 2-400rpm. Unless it was an extremely deep day it always felt like there was power left to put to the ground. Climbed virtually the same hills in stock form and was way slower climbing the same thing as after a gear up. I’m not a huge guy either so it’s not like the sled has to work a ton to haul me around. I can’t really explain it. Going to 21-49 gearing on the pro climbs made it feel the way the 2018 mountain cat felt with the stock gearing, drop and roll chain case and 8 tooth drivers that came factory with 3” track. I believe cat went to that 19/50 lower gearing when they were having all the issues with blowing belts on the higher geared 12&13’s. Clutching and engine mounts were a lot better on the 14-16 proclimbs so no need to gear that low I found and was a better overall sled after


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[Clode]

The stock gearing on my '16 never kept the engine loaded, and it would run out of gear and go flat, with the gear up it kept the engine loaded and it never fell on its face anymore. Another benefit was getting the rpm down on the trail, the thing was at like 7000rpm going 70km/hr with the stock gears.

 

[drew562]

Not a clutch guy. But I am a belt spitter. When I rode boosted Yamaha’s I couldnt keep a belt in for the first year. (Like most sleds)After some asking around. I took it to Nick King at Vernon Motorsports. He did A Bunch of clutching and weight changes and he geared it up. Never blew belt again. I used that same combo in multiple Yamaha’s with the same result.

 

[Teth-Air]

I always felt like it had more track speed in it and was just making more noise with more throttle and not picking up speed with the stock gearing and over revs from time to time by about 2-400rpm. Unless it was an extremely deep day it always felt like there was power left to put to the ground. Climbed virtually the same hills in stock form and was way slower climbing the same thing as after a gear up. I’m not a huge guy either so it’s not like the sled has to work a ton to haul me around. I can’t really explain it. Going to 21-49 gearing on the pro climbs made it feel the way the 2018 mountain cat felt with the stock gearing, drop and roll chain case and 8 tooth drivers that came factory with 3” track. I believe cat went to that 19/50 lower gearing when they were having all the issues with blowing belts on the higher geared 12&13’s. Clutching and engine mounts were a lot better on the 14-16 proclimbs so no need to gear that low I found and was a better overall sled after


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For sure lower gearing can feel slower if the clutch doesn't shift to compensate. When the clutch does shift it should result in the same track speed only with the belt riding higher in the primary sheaves. I would expect the gearing you went to was just a better match for the clutching you had. I like adjustable weights to fine tune for these types of conditions.

 

[tmo1620]

For sure lower gearing can feel slower if the clutch doesn't shift to compensate. When the clutch does shift it should result in the same track speed only with the belt riding higher in the primary sheaves. I would expect the gearing you went to was just a better match for the clutching you had. I like adjustable weights to fine tune for these types of conditions.

Ya I was running the gearing and clutching changes, with adjustables. Also was running full exhaust, intake, head and a couple different tunes on a couple of those cats as well but that’s another story lol. The good thing with doing gearing is it gets two bird stoned at once in the proclimbs. Put the venom kit in and it gets rid of the pathetic aluminum bottom gear, the useless auto tensioner and a way more durable hyvo chain over stock, all for less money and time than the clutching takes


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