Exciter knowledge 101

Can someone please help me out with the drive chain and sprockets on the ex570?

Stock Setup I believe was:
17tooth Upper
31tooth Lower
Chain: 94890-05066-00 (66 Links???)
Here is my current setup:

18tooth upper (Optional)
31tooth Lower (Standard)
66 links in my chain

My questions are:

What sprocket setup would require me to go to a 64 link chain?
How many links are in these chains, can i assume its the last number (64,66,68,70)? 94890-05064-00, 94890-05066-00, 94890-05068-00, 94890-05070-00

Thanks guys!
 
stanage said:
Can someone please help me out with the drive chain and sprockets on the ex570?

Stock Setup I believe was:
17tooth Upper
31tooth Lower
That is correct.

Chain: 94890-05066-00 (66 Links???)
Also correct.
Here is my current setup:

18tooth upper (Optional)
31tooth Lower (Standard)
66 links in my chain

My questions are:

What sprocket setup would require me to go to a 64 link chain?
15/29 gearing it is recommended to change to a 64 link chain.

How many links are in these chains, can i assume its the last number (64,66,68,70)? 94890-05064-00, 94890-05066-00, 94890-05068-00, 94890-05070-00
I'm not positive on the part numbers, but your theory makes sense.

Thanks guys!
Click to expand...

What is it you are trying to achieve with your gearing? Top speed, better acceleration, or better deep snow performance? You have me curious.
 
hmmm i have 17/31 on mine, 15/29 sounds pretty nice though! I thought alot of gearing down, but i think i settle with smaller drivewheels for now:)
 
prankster said:
hmmm i have 17/31 on mine, 15/29 sounds pretty nice though! I thought alot of gearing down, but i think i settle with smaller drivewheels for now:)
Click to expand...

15/ 29 only nets you a 1.93 gear ratio. Not sure why it is even listed. You can better achieve that same ratio with 16/31. 16/33 would get you to 2.06.

Remember, try to keep the largest sprockets you can to still achieve your desired gearing. Smaller radius turns put more stress on the chain and can rob HP. You want larger diameters for less rolling resistance.

I'm not so much a HP nut as an efficiency nut. Lol ;)! A typical snowmobile will experience 40-45% HP loss from the crank to the track. So if the exciter is at 80HP only about 44 of the ponies ever make it to the track! Most people don't realize this.

The same holds true with smaller drivers. It does gear you down, but now that stiff track has a tighter radius to go around. Ever seen the big wheel kits for mountain sleds? Same idea. Create a larger radius for less resistance. Just my .02 and some food for thought.
 
Approximate Diameters on track drivers :

2,52" pitch :
7T = 5.50"
8T = 6.25"
9T = 7.05"
10T = 7.85"


1 teeth down on a 2,52" track drivers is like 2 teeth down on upper gear.



An old rule of thumb is that to get a fun sled aim for around 2,00 gearing calculated with ( 2,52" ) 9-Teeth track driver !


15/29 = 1,933
16/29 = 1,812
17/29 = 1,705
18/29 = 1,611
19/29 = 1,526
20/29 = 1,450
- - - - - - - - -
15/31 = 2,066
16/31 = 1,937
17/31 = 1,823
18/31 = 1,722
19/31 = 1,631
20/31 = 1,550
- - - - - - - - -
15/33 = 2,200
16/33 = 2,062
17/33 = 1,941
18/33 = 1,833
19/33 = 1,736
20/33 = 1,650
- - - - - - - - -
15/35 = 2,333
16/35 = 2,187
17/35 = 2,058
18/35 = 1,944
19/35 = 1,842
20/35 = 1,750
- - - - - - - - - -
15/37 = 2,466
16/37 = 2,312
17/37 = 2,176
18/37 = 2,055
19/37 = 1,947
20/37 = 1,850



I'm not aware of what different gears their is for the EX-570 sled !?!?
Maybe someone could enlighten me ?

:2strokes:
 
Last edited:
Lasse said:
Approximate Diameters on track drivers :

2,52" pitch :
7T = 5.50"
8T = 6.25"
9T = 7.05"
10T = 7.85"


1 teeth down on a 2,52" track drivers is like 2 teeth down on upper gear.



An old rule of thumb is that to get a fun sled aim for around 2,00 gearing calculated with ( 2,52" ) 9-Teeth track driver !


15/29 = 1,933
16/29 = 1,812
17/29 = 1,705
18/29 = 1,611
- - - - - - - - -
15/31 = 2,066
16/31 = 1,937
17/31 = 1,823
18/31 = 1,722
- - - - - - - - -
15/33 = 2,200
16/33 = 2,062
17/33 = 1,941
18/33 = 1,833




I'm not aware of what different gears their is for the EX-570 sled !?!?
Maybe someone could enlighten me ?

:2strokes:
Click to expand...


There could be others, but here is what I could come up with,

Upper:
829-17682-50-00 SPRKT,CHAIN DR 15T
829-17682-60-00 SPRKT,CHAIN DR 16T
829-17682-70-00 SPRKT,CHAIN DR 17T (STD)
829-17682-80-00 SPRKT,CHAIN DR 18T
829-17682-00-00 SPRKT,CHAIN DR 19T
829-17682-90-00 SPRKT,CHAIN DR 20T

Lower:
878-47548-90-00 SPROCKET,CHN DRVN 29T
8U9-47587-00-00 SPROCKET,CHN DRVN 31T (STD)
8U9-47587-10-00 SPROCKET,CHN DRVN 33T
878-47587-20-00 SPROCKET,CHN DRVN 35T
8U9-47587-30-00 SPROCKET,CHN DRVN 37T

Chains:
94890-05064-00 CHAIN 64 Links
94890-05066-00 CHAIN 66 Links (STD)
94890-05068-00 CHAIN 68 Links
94890-05070-00 CHAIN 70 Links
 
thefullmonte said:
What is it you are trying to achieve with your gearing? Top speed, better acceleration, or better deep snow performance? You have me curious.
Click to expand...

OK, so here goes:

Basically, I traded for this sled, and didn't really know what I was getting. It has a comet 108exp clutch, 18/31 gearing, PSI pipe, Stock drivers, stock pistons, cylinders are port and polished. I also extended the track/tunnel from a 121 to a 136inch with a 1.3 camoplast cobra track. No other mods to speak of, other than a lack of an airbox(POD Filters)

My goal is to have a good all round sled that will get me though some deep snow at a fairly decent speed, while still achieving atleast 70-90MPH on flats. I want to be able to go through the woods(Deep snow) at low speed, and still fly through powder when its around. I also plan on pulling a sleigh with some fishing gear when I decide to go fishing... but it's not a huge sleigh.

At this point my sled is only able to run a top speed of 70km/h (43mph), and I need to know what to do to get it back to normal!? I assume I need to re-clutch, and possibly gear down the top sprocket? At this point -> Im lost. ;):D

On top of that, I don't have the tools to take my clutch apart to see whats in there with regards to clutch weights and springs, however I do know I have a red primary spring. Also, it seem as though my engagement RPM is slightly below 4000RPM.

Any help, or guidance would be appreciated.
 
Last edited:
thefullmonte said:
What is it you are trying to achieve with your gearing? Top speed, better acceleration, or better deep snow performance? You have me curious.
Click to expand...

OH, and the reason I asked about the 64link chain, was cuz there was a cheap NOS one on ebay for $50!
 
well stanage, looks like we´re searching for the same answers:) You described it perfect up there, i got the same set up, except i got the silver spring in my primary. I also need to mention that i got stock secondary...(maybe a vmax secondary could work, it should be easier to find a clutch kit for that).
 
43 mph?what belt u runnin and how much clearance at front sheaves to belt.my first thought is u need a vmax 600 belt.whats youre top rpm?take a magic marker and draw a line up the clutch face and see how far the belt wears it off.
 
stanage said:
OK, so here goes:

Basically, I traded for this sled, and didn't really know what I was getting. It has a comet 108exp clutch, 18/31 gearing, PSI pipe, Stock drivers, stock pistons, cylinders are port and polished. I also extended the track/tunnel from a 121 to a 136inch with a 1.3 camoplast cobra track. No other mods to speak of, other than a lack of an airbox(POD Filters)

This is just my opinion, but with stock drivers I think you are geared too tall. Especially if you want good all around performance. Stock was 17/31 and many people go to 16/31 which is still only a 1.94 gear ratio. 18/31 is 1.72 and would be more of a top speed lake racing setup and not very likely the sled was capable of reaching it. As Lasse pointed out you want to be real close to 2.0. If you do a lot of powder riding you may want to get even closer to 2.25.

My goal is to have a good all round sled that will get me though some deep snow at a fairly decent speed, while still achieving atleast 70-90MPH on flats. I want to be able to go through the woods(Deep snow) at low speed, and still fly through powder when its around. I also plan on pulling a sleigh with some fishing gear when I decide to go fishing... but it's not a huge sleigh.

At this point my sled is only able to run a top speed of 70km/h (43mph), and I need to know what to do to get it back to normal!? I assume I need to re-clutch, and possibly gear down the top sprocket? At this point -> Im lost. ;):D

I hope I don't sound like a know it all. Because it's hard to say without the sled in front of me, but I tend to think some of your issue is gearing. If you take a marker and draw a line on your clutch sheaves and give it a good run I bet you will find that you aren't shifting all the way out. It's just too much load. Plus you increased the clutch load by adding a longer deeper lug track. On more than one sled I have geared down and went faster because the clutch was able to pull the load.

On top of that, I don't have the tools to take my clutch apart to see whats in there with regards to clutch weights and springs, however I do know I have a red primary spring. Also, it seem as though my engagement RPM is slightly below 4000RPM.

I will try to do a little more research on the comet setup at work for you.


Any help, or guidance would be appreciated.
Click to expand...
:letitsnow
 
dsc577 said:
43 mph?what belt u runnin and how much clearance at front sheaves to belt.my first thought is u need a vmax 600 belt.whats youre top rpm?take a magic marker and draw a line up the clutch face and see how far the belt wears it off.
Click to expand...

I'm running an ultimax pro 125-4320U4
My top is rpm is a little over 7k
Front sheave to belt gap is around 3/16

I'll do the test with the marker and get back to you
 
Last edited:
front sheave gap way to high,should be measured with a feeler guage,108's typically come setup for the wider belt unless you take it apart and remove a spacer youre gonna need a wider belt.i used a 1118,
you dont need any tools to take the cover off,just unbolt it slowly and evenly,theres not to much spring pressure to worry about,spring is probably red with a silver mark on it,weights may be f-2,55 grams,
 
OK guys i have a question... I got a 87 exciter thats bean a work in progress since i got it when i was 12 4 yrs later im almost done but i got a track from a wrecked sled its a 121x15x1.5 i want to get a set of 7 in wahlbroos non rachet drivers but it say they are 3.0 pich but my track is a camo intense 2.52 pich can i still run it??
 
This is VERY interesting! I think I may try and locate a 16 tooth gear to see what kind of difference it makes. That will get me closer to a 2.0 ratio. Otherwise what your saying is an 8 tooth driver will do the same thing as dropping 2 upper gear teeth... Decisions decisions...
 
87YAMAHA-570 said:
I got a 87 Exciter,
and want to put on a track from a wrecked sled, it's a 121x15x1.5
I want to get a set of 7-T wahlbroos non rachet drivers but it say they are 3.0" pitch but my track is a 2.52" pitch.
Can i still run it ??
Click to expand...
NO, totally wrong pitch on the drivers !
You must get drivers with the right pitch for your track ---> 2,52"


;)! A very wise/smart choise to go for No-Slip drive sprockets ;)!


Look here : http://www.wahlracing.com/product.php?productid=19876&cat=276&page=1&click=srclick


Do not go for smaller drivers then OEM 9-Teeth drivers unless you need it for clearance issues !

:2strokes:
 
Last edited:
stanage said:
My sled has a :
* Comet 108exp clutch.
* 18/31 gearing.
* PSI pipe, Stock drivers.
* Stock pistons.
* Cylinders are port and polished.
* I also extended the track/tunnel from a 121" to a 136"x15"x1.3" track.


My goal is to :
* Have a good all round sled that will get me though some deep snow at a fairly decent speed.
* Achieving atleast 70-90MPH on flats.
* I want to be able to go through the woods (Deep snow) at low speed,
and still fly through powder when its around.
* I also plan on pulling a sleigh with some fishing gear when I decide to go fishing...
but it's not a huge sleigh.
Click to expand...
:itchy: One thing at a time...
...and you could not get it all ! :itchy:


Your gearing for that track is not good !
What size on your track drivers 7, 8 or 9-teeth ??
 
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Guys i really need some advice here, got the silver spring in my comet right now. The one i had before had a yellow/green spring. How do i know which spring to use. These things are like aliens to me:)

I´m after the same goal as stanage, a quick, strong sled that works good in powder. I think i´ll use the 8 tooth no slips for mine;)
 
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