Variable exhaust - Snowmobile Forum: Your #1 Snowmobile Forum

snonut12 · 01-20-2008, 12:53 PM

Sorry if it's a stupid question but exactly what does VES do that is different from non VES sled? My guess it is something to do with power but am not sure. I'm trying to determine how the XC differ from XCSP.

**smallengineguy** · 01-20-2008, 08:56 PM

VES basically opens up the exhaust port at the right time, changing the power band of the engine.

huskysled · 01-20-2008, 08:57 PM

Check polarisman.com for the differance between XC and XC SP. Some years it was only additional items like seat pads etc. It had nothing to do with the VES.
The VES (Veriable Exhaust System) monitors exhaust pressure in the cylinder via a diaphram/spring. The regulated pressures, unlike a non-VES motor, result in better/cleaner burns in the cylinder creating added HP. The newer HO engines then came out with vaccum controlled VES and now electronic assisted VES. Ski-Doo originally came out with this type system in the early 90's (Mach Z and MX Z).
However, small engine guy is the resident expert. I only think I know a little.

Cheers

huskysled · 01-20-2008, 08:58 PM

Dang, SEG beat me to it. Thanks, SEG

**smallengineguy** · 01-20-2008, 10:12 PM

You got it right, though, Huskysled!

lrnnorth · 01-21-2008, 02:39 AM

So do the standard motors without valves make more horse power than the same size engines with the ves?

**smallengineguy** · 01-21-2008, 07:27 AM

NO, VES make more, because they "self tune" with different RPM's.

Indy600 · 01-23-2008, 03:31 PM

Dont forget to clean the valves on a yearly basis. I got lazy last year and then remember that I had to do it this year. I had a ton of crap on there.

lrnnorth · 01-23-2008, 04:40 PM

Thats what i thought but i was wondering because it seems like all the aftermarket compainies' hp increase claims seem to be larger for the big-block motors. Like for a pipe for the small block is 8 hp and the big block is 10 hp. Why is this?

H2oSprayer · 01-24-2008, 11:07 AM

Quote:

Originally Posted by Indy600

Dont forget to clean the valves on a yearly basis.

Any chance of a tutorial on how to remove and with what and how to clean?

**RJ Gleason** · 01-24-2008, 01:48 PM

http://www.snowmobileforum.com/engin...-tos-here.html

H2oSprayer · 01-24-2008, 02:29 PM

Quote:

Originally Posted by RJ Gleason

http://www.snowmobileforum.com/engin...-tos-here.html

Thanks for the link. There is a ton of great stuff there. But I didn't see anything about cleaning the VES valves. Did I overlook it?

Indy600 · 01-24-2008, 03:39 PM

It really is a piece of cake. I can not remember the size of the wrench (either 8 or 10mm) there are 4 bolts on each valve under the spring housing (black). You just have to remove those 4 bolts and then just slide the valve right out. If it is all gooked up, it will be difficult to slide out. There will be a gasket under there. Mine was a light green. Check it for cracks or tears. If it is bad, get a new one. A couple bucks for the gasket. Dont worry about putting it in the wrong way, there is a locator pin on it so that you can not put it in the wrong way. Pulling the bolts is a little tedious, unless you have a crows foot ratchet. I do not have one of those. your cramped up hands will make you appreciate it all the more. When you get it out you can use either a brillo pad or wire brush. I would be careful with scraping the valve though.

amynjimmy · 11-02-2009, 04:20 PM

Cleaning the VES should be done yearly???? I dont know if mine has ever been done. how can u tell if it needs to be done?

**RJ Gleason** · 11-02-2009, 05:14 PM

If there is any carbon build up on the guillotine, it needs cleaning.

NonStikCookWare · 11-02-2009, 08:39 PM

Quote:

Originally Posted by amynjimmy

Cleaning the VES should be done yearly???? I dont know if mine has ever been done. how can u tell if it needs to be done?

Once a year is the minimum! i doo mine every 500 miles. And if u want better fuel milage and better pull, then tighten your ves down all the way, and turn it out two notches (this is also the best setting for 660 drag racing)

**BC_Dan** · 11-02-2009, 10:56 PM

The newer valves are not adjustable... the only adjustment is to swap springs. There are different colored springs for different altitudes.

amynjimmy · 11-03-2009, 01:27 PM

im a little new at the VES thing....I have no idea how to even begin

**BC_Dan** · 11-03-2009, 01:43 PM

I posted a thread on removing and cleaning, it has pictures

hope that helps!

http://www.snowmobileforum.com/polar...-assembly.html

NonStikCookWare · 11-03-2009, 02:37 PM

The best thing i ever did for taking my ves out of my 2001 was cut the end off the wrench and weld it back on 90 degrees. Now i can get a full turn on the bolt instead of little quarter turns lol