Wizzard717
New member
First off, i'm in the middle of doing a 144 stretch on a 121 viper. I just picked up this viper a few weeks ago and i'm gutting the stock skid/drivers out. I was told that this sled is 100% stock and only had two owners but shortly after i got it home i noticed it had a heelclicker clutch kit on it. Anyways, so tonight i ripped the "stock" drive axle out of it. Now lemme tell ya, i've ripped out many many driveshafts but this viper was by far the worst one yet. 
Horrible design to have to rip the chaincase off. So after i get the darn thing out i'm looking at it and thinking to myself....i thought stock drivers had 4 cogs and were 9 tooth ?? This has only 2...extrovert ?? I dont know much about extrovert drivers as i've never had them. I count the teeth and there is 8. Now as I look at my 8tooth drivers i bought from ebay i notice what i just ripped out of the sled is larger diameter but its also 8 tooth. I'm just confused. So my goal is to put the driveshaft with 8 teeth back in the sled that i bought off ebay. But as the pictures show, i have some issues to figure out first. How do i pull the bearing retainer clip off the 2 cog shaft ? why doesnt the new driveshaft have the retainer clip already on it ? It seems like the two shafts have different total lengths.....Can anyone chime in here to maybe figure this out....
Thanks, Adam
Horrible design to have to rip the chaincase off. So after i get the darn thing out i'm looking at it and thinking to myself....i thought stock drivers had 4 cogs and were 9 tooth ?? This has only 2...extrovert ?? I dont know much about extrovert drivers as i've never had them. I count the teeth and there is 8. Now as I look at my 8tooth drivers i bought from ebay i notice what i just ripped out of the sled is larger diameter but its also 8 tooth. I'm just confused. So my goal is to put the driveshaft with 8 teeth back in the sled that i bought off ebay. But as the pictures show, i have some issues to figure out first. How do i pull the bearing retainer clip off the 2 cog shaft ? why doesnt the new driveshaft have the retainer clip already on it ? It seems like the two shafts have different total lengths.....Can anyone chime in here to maybe figure this out....Thanks, Adam
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Make sure you know the pitch of the drivers. Your track will have to match of course.
There should be 2 torx head set screws in the speedo bearing. Remove those and then work the bearing off. You will likely need to use a good penetrating oil like Kroil, Deep Creep, PJ Blaster, Jigaloo, etc. This will allow you to get the bearing retainer off. If you want to reuse the bearing be sure to only press on the inner race.
On the other end - that is a collar that the seal rides on. It should have an o-ring in it. It should simply slide off. You may need the penetrating oil again. The o-ring is important as it seals the shaft.
These look like Wahl extrovert drivers, but I can't tell the pitch from the picture. Be sure to measure. One way is to measure the circumference and divide by the number of teeth.
I am guessing someone just put the speedo bearing back on after removing from the sled.
There should be 2 torx head set screws in the speedo bearing. Remove those and then work the bearing off. You will likely need to use a good penetrating oil like Kroil, Deep Creep, PJ Blaster, Jigaloo, etc. This will allow you to get the bearing retainer off. If you want to reuse the bearing be sure to only press on the inner race.
On the other end - that is a collar that the seal rides on. It should have an o-ring in it. It should simply slide off. You may need the penetrating oil again. The o-ring is important as it seals the shaft.
These look like Wahl extrovert drivers, but I can't tell the pitch from the picture. Be sure to measure. One way is to measure the circumference and divide by the number of teeth.
I am guessing someone just put the speedo bearing back on after removing from the sled.
Wizzard717
New member
The drivers i bought from ebay are oem 8tooth yamaha viper drivers. I dont undetstand why these are both 8tooth but one is bigger then the other. Makes no sense to me
If the pitch is longer, the circumference will be larger. There are a number of different pitches. Stock Yamaha pitch is 2.52 on the shorties. Other common sizes today are 2.86, and 3.00. Take a string (non-stretch kind) and wrap around the drivers where the track will go. Mark where the string meets and then lay flat and measure. This will give you your circumference. Then divide by the number of teeth to get the pitch.
There is 2.52" pitch and 3" pitch drivers. Pitch is the distance between the lugs on the track/drivers/center of one drive window to the next/etc. 8 tooth 2.52" pitch drivers will be smaller than 3" pitch drivers. I'm betting the bigger one is 3" pitch and the small is 2.52". Try to measure the distance between the lugs of your drivers. You have to match it to your track as well.
EDIT: Ding beat me to it.
EDIT: Ding beat me to it.
Wizzard717
New member
I guess I should of mentioned i'm fully aware what pitch is.....the track that was on these 2 cog drivers was a 121x1x15 camoplast predator.....which is a trail track, 2.52 pitch. I know this because i put this same exact track on a skidoo I own. Both drivers are 2.52. The 4 cog drivers are "stock" yamaha 8tooth drivers 2.52 pitch. The 2 cog are 2.52 also because of the track I removed.....unless you can run a 2.52 pitch track on the wrong drivers ? Is it possible ?? I will measure when i get home later on on both of them and calculate the pitch.
there is also a 2.8 pitch
if you have 8tooth 2.8 it will have the same diameter as 9tooth 2.5 pitch and 7 tooth 30 pitch
if you have 8tooth 2.8 it will have the same diameter as 9tooth 2.5 pitch and 7 tooth 30 pitch
Wizzard717
New member
Like i said, the 2 cog drivers i pulled out of the sled drove a 121x1x15 track which was a camoplast predator. Thats a 2.52 track. The OEM 4cog drivers i bought on ebay are "Stock" 8tooth drivers for a viper/venom. Stock is 2.52 pitch for these sleds. Unless these "stock" drivers i got on ebay are a different pitch ? I'm just confused...lol. The mountain vipers run the same 8tooth drivers i think...they run a 144" track which is 2.52. Someone correct me if i'm wrong. Also, if the 2 cog drivers ARE 2.86, is it possible to run a 2.52 track on 2.86 drivers ? Just curious...maybe thats whats going on here.
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you can not interchange pitches.
just throw a tape on the driver and you will know. measure at the back of one lug to the back of the next, that is your pitch. this measurement is at the base of the extrovert lug.
also, measure your track lug pitch or look up the part number on the outside of it. it will tell you what pitch the track is.
just throw a tape on the driver and you will know. measure at the back of one lug to the back of the next, that is your pitch. this measurement is at the base of the extrovert lug.
also, measure your track lug pitch or look up the part number on the outside of it. it will tell you what pitch the track is.
Wizzard717
New member
Im an idiot....they are both 8 tooth 2.52 pitch. It "looks" bigger because the extrovert drivers have the knobs on top. i measured the diameter of the actual driver and they are both 6.25" across
Nope, you are just in the process of figuring it all out. Sounds like you are in good shape, did you get the bearing and the collar off?Wizzard717 said:
btw: they did both look like 2.52 pitch drivers but it is always hard to tell for sure by just looking at the pics
Wizzard717
New member
Now that i figured out they are the same drivers, i'm going to re-use the extros....all i hear about are how good they are so i mine was well throw them back in there once i put the new track in. The only thing is i think i'll have to cut the heat exachanger protectors...i'm going with a 1.5 or 1.625(cut lug) 144 track with no studs. Looks like its already geared down with the 8tooth drivers as opposed to stock 9 tooth. Now to figure out this heelclicker clutching thats on it.....was hoping it just had stock so i know what im dealing with.