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'98 700 RMK's don't have it. VES stands for Variable Exhaust System, which is basically and exhaust valve that opens one of two ways: pressured exhaust gases or electronically. You can tell if it has valves by looking above the header there will be to black things, like in the pic of the 600 with VES.
[attachment=57343]
 

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You would be wasting your time with a sled thats none ves. In my book it makes a world of difference but some people think this it does alot power wise. But think about this. I have a 600 ves and my buddy has an 800 none ves, and my sled beats his.
 

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That has very little do do with why your sled beat his. There are a whole lot of other factors that come into play as well. Ves isnt the main reason why you won.
 

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True, In fact i beleive one of the fastest 700's polaris made was the 98 XC 700, and it didn't have VES. But VES usually adds 6-8 hp to a sled, for example, the big block non VES was around 120 ish hp, and the 01 700 with VES was about 128-130. So yes you do gain some from the VES.
 

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actually its really meant to increase top end. The nice thing about the valves is they stay closed at low rpm to maintain good low rpm torque, and then open at higher rpm to allow better flow and more top end hp. I love it when the valves open on my sled, you can hear the whole tone of the engine change and then a extra surge of power comes on tap.
 

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Variable exhaust valves let the engine builder make the engine work well at all rpm ranges. Usually they have to make a compromise when they design the exhaust ports, but with VES it always has the right exhaust port height for the given rpm.
VES makes the engine run more efficiently, which allows it to make more power and get better fuel economy.
Also, VES is such a simple design that you almost never have problems with it. Other than cleaning the slide once a year, other than if you get a tear in the bellows there is really no maintenance with VES.
Honestly, I wouldnt buy a 2-stroke sled that doesnt have VES.
 

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Originally posted by xlt580man
[br]You would be wasting your time with a sled thats none ves.
I don't know that I would go that far. VES is a variable exhuast system. The parts are essentially a bellow, and a guillotine slide valve. The pressure that builds up in the bellow is used to move the valve up against a spring which pushes it down, the valve covers or uncovers part of the exhaust port. Port height is one of the determining factors of the behavior or a 2-stroke engine. A high port height means that you would have a strong top end, but that the low end torque was non-existent. If the port were set low, you had a very strong low end, but the motor began "gasping for air" so to speak at high RPM. The VES system's valve changes the overall height of the port depending on combustion pressure. This allows the engine to have a low port at low RPM and a high port at high RPM. What actually provides the power gain is that the designers can move the port higher up than a non-VES motor, allowing for an even stronger top end pull, while minimizing the losses on low end. Generally, the motor with VES will have more power, but that doesn't mean that non-valved motors aren't worth looking at. Sleds without VES are generally cheaper to buy and are able to run the cheaper grade of oil (not that it means you should run garbage oil either. . .) Generally, the valves will net you up to about 10 hp on a given motor. The valves DO require a premium oil however, so figure that into your cost deliberations.

Polaris first released their VES in about 1998 on the 440 XCR SP and the first production sled to have it was the 2000 500 XC SP. The 700 you are looking at is one of the big block liberty's and would not have VES. They are still strong motors and have quite a following on this site.

500 XC (no VES)
[attachment=57423]
 

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Very wrong on your dates. Polaris came out with the valves in the 97 xcr 440 no sp designation till it was in the edge chassis.
98 was the first production year of the ves still in the 440.
00's it was available in the sp version of the 500 xc.
 

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kinda makes one wonder why Ski Doo ,had ves way back in the late 80's
 

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the ves helps make low and midragne throttle response. peak hp has nothing to do with ves. the hp changes were other changes not ves.
 

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Originally posted by stormrider62033
[br]kinda makes one wonder why Ski Doo ,had ves way back in the late 80's
Power! That's why.
 

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Originally posted by madcow
[br]the ves helps make low and midragne throttle response. peak hp has nothing to do with ves. the hp changes were other changes not ves.
Ummm, no..
 

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Read this....
[attachment=50177]

came on 440,500,600,700,800 twin and triple.
 

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Originally posted by CanadianXCR
[br]
Originally posted by madcow
[br]the ves helps make low and midragne throttle response. peak hp has nothing to do with ves. the hp changes were other changes not ves.
Ummm, no..
The VES valves could have no effect on high RPM running because at WOT, the valves are pulled completely out of the port, which means they are no longer affecting exhaust flow, which means they are effectively not even there. If the valves were removed and the holes plugged, the high RPM of the power band would show no change. The low end and mid range are what would suffer.
 

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^^^^Ummm yes
 

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because rotox builds good engines, I have an mxz 670 with rotary intake and R.A.V.E. exhaust and that engine has awsome torque. The Austrians have so different ideas KTM for another good example.
 
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