Plugged Exhaust Valves?

600xc4me · Nov 20, 2009

Kraven said:
Easiest way is to remove the "T" and replace with a 5/16" stud approx 2"- 2 1/2" long (bolt with the head cut off will work fine) clamp and you're done. It will look like the cylinders are connected, yet they're plugged individually.

The hose going to the solenoid, tie wrap it up, doesn't matter as the opposite end is vented to the atmosphere. You may need to reconnect this if you have to bring your sled in for warranty purposes.

Do NOT disconnect the wires going to the solenoid, this will cause an error message to pop up on your MFD display.

Hope this helps

Right on thanks, with that once I look at the sled closer I'll see what you mean I'm sure. Thanks. My dealer knows I'm changing springs, but not that I'm plugging the lines. Not yet anyway. But they have always been good when it comes to warranty issues.

knee deep in it · Nov 20, 2009

I am building an 06 600 rmk. The solenoid valve had the outlet hose plugged off. I was wondering about this before I saw this thread. Assuming I ride 3,000 to 7,000 feet, can I keep it plugged and just run the stock exhaust valve springs?

Kraven · Nov 20, 2009

knee deep in it said:
I am building an 06 600 rmk. The solenoid valve had the outlet hose plugged off. I was wondering about this before I saw this thread. Assuming I ride 3,000 to 7,000 feet, can I keep it plugged and just run the stock exhaust valve springs?

Probably. I recommend plugging at the "T" because I prefer blocking individually, but it's personal preference, that's all. As long as you got it plugged, you're good to go.

Someone posted earlier that the older (2001-2005 600's) and the newer 600's take the same exhaust spring, so no need to change springs on the 600???

I know on the 800's the exhaust springs are different old to new.

thefullmonte · Nov 20, 2009

So, hypothetically speaking

with the tubes plugged your valves should open sooner even with the stock springs anyway. From what I'm reading, It is my understanding is that the solenoid is holding them shut until a specified rpm rather than a vacuum pressure. When the solenoid releases or whatever it does the valve receives full pressure and goes to full open.
Which makes me think that there is another benefit in the fact that with the solenoid it is likely either full open or full closed which kinda defeats the purpose of the Variable Exhaust System. With the system plugged, the valves can open to different degrees depending on pressure. Of course this is all very minimal as they are usually either open or closed anyway right!

Gees, this is making me think....ouch

towngrunt · Nov 20, 2009

O.K. lets add a new twist to this equation. I have a 06 600 RMK with a carls 660 kit in it which spring would I use? Would it be one for the 600 or the spring for the 700?

AKCoop · Nov 21, 2009

So do I have this right?

The seliniod does not provide varible opening to the exhaust valves, only an open or closed pressure. The spring provides the required mechanical pressure to actually close the valve.

In this case the selinoid is holding the valve closed until the signal is sent to "release" the valves.

Or is the selinoid actually allowing partial opening?

Just a couple of questions. Thanx!

Mandic · Nov 21, 2009

Kraven said:
Someone posted earlier that the older (2001-2005 600's) and the newer 600's take the same exhaust spring, so no need to change springs on the 600???

By Polaris' parts information the 600HOs, and 600VES engines use the exact same Pink spring. Same part number and all. The 700 RMK CFI engines use this same spring.

The 600CFI engines and previous 700 Dragon(121) use a Purple spring. And the 09+ 800s have an Orange spring.

So it really seems it depends on your elevation and what you are doing with the sled.

For someone like me who rides around 1500 feet on trails and lakes all day on a 600HO engine, I don't see any reason to change springs. Works well in a 600VES with the same spring combination, so for me it is good. I lucked out I guess.

Look at the Polaris parts breakdown for your sled and figure out what it has. I just checked about 6 or 7 models over a span of years from 07-09 and found different springs in the same engine depending on year/model. RMK vs 121 sled, etc etc.

This is my Local dealer's site but it has the parts breakdown available for research at least. I don't even bother having the parts guy look stuff anymore, I figure out what I want/need and take the numbers to him.

Kraven · Nov 21, 2009

AKCoop said:
So do I have this right?

The seliniod does not provide varible opening to the exhaust valves, only an open or closed pressure. The spring provides the required mechanical pressure to actually close the valve.

In this case the selinoid is holding the valve closed until the signal is sent to "release" the valves.

Or is the selinoid actually allowing partial opening?

Just a couple of questions. Thanx!

Think of the solenoid as a drain valve on your air compressor tank. Normally the solenoid is open, allowing pressure to escape ,(via the "purge hose that vents to the front of the hose/bellypan) and therefore the exhaust valves remain closed.

When the solenoid activates, stopping the escape of the air pressure which causes the exhaust valves open.

The solenoid is either FULLY on or FULLY off, there is no in-between.

Hope this helps.

Mandic · Nov 21, 2009

So if the valve is normally open it also functions as a decompression hole too huh? Not that I noticed any harder starting after I removed the solenoid setup, but it was warm when I last started the sled up.

Kraven · Nov 21, 2009

Exhaust valve & De-compression hole

Mandic said:
So if the valve is normally open it also functions as a decompression hole too huh? Not that I noticed any harder starting after I removed the solenoid setup, but it was warm when I last started the sled up.

No, exhaust valve is normally closed, the exhaust spring keeps it closed.

Has nothing to do with the decompression hole, that is unaffected.

milehighassassin · Nov 21, 2009

So for those with the 800 motor, what is the color you should use at higher elevations? Seems white is the lightest spring rate, but I keep hearing yellow. What is the FULL POLARIS part number?

Say 8000' +

Rich07Dragon700 · Nov 21, 2009

Kraven said:
Probably. I recommend plugging at the "T" because I prefer blocking individually, but it's personal preference, that's all. As long as you got it plugged, you're good to go.

Someone posted earlier that the older (2001-2005 600's) and the newer 600's take the same exhaust spring, so no need to change springs on the 600???

I know on the 800's the exhaust springs are different old to new.

Kravan, thanks for taking the time for all of your EXCELLENT posts on Snow-West & HCS!!!

Since last year I have been considering plugging the exhaust valve's black rubber hoses on my 2009 600 CFI-4 Switchback with SLP pipe, SLP can, SLP MTX weights, Gabe's Team secondary set-up, my cheap high flow intake, etc. As I can fell a large power surge at 7500 RPM, runs strong to 8400 rpm. Is this power surge from the SLP pipe or exhaust valves opening up late at 7500 rpm???

---I think the 7500 rpm power surge is from late exhaust valve opening to improve EPA.
---If my memory is correct the 2002 600 Poo's exhaust valves opened at approx 6900 rpm.
---If my engine's exhaust valves open at (7500 rpm ?) it has to reduce mid range power and increase heat to pistons and exhaust valves.

Quick easy, looks stock:
Today I removed the two rubber hoses off from the exhaust valve assemblies nipple, which measured .243" O.D..
---Then I cut a .250" dia bolt into two smooth .75" long pieces.
---Then pushed the .25" Dia x .75" long smooth bolt pieces into the end of both black rubber hoses.
---Then pushed the rubber hose back onto the exhaust valve nipple, pushing in the bolt piece. Added a extra clamp to hold, seal off the short bolt piece.

Note:
---2009 Switchback 600 CFI-4 exhaust valve Purple spring #7041704-04.
---2002 600 XC exhaust valve pink spring #7041704-03.
Safe Sledding; Rich

Kraven · Nov 21, 2009

800 exhaust springs for high altitude

milehighassassin said:
So for those with the 800 motor, what is the color you should use at higher elevations? Seems white is the lightest spring rate, but I keep hearing yellow. What is the FULL POLARIS part number?

Say 8000' +

Mile High,

I used to have a 2002 EDGE-X 800, trailered it 1500+ miles (one way) to Yellowstone 3 times, I installed the YELLOW (high altitude, softer tension than stock) springs pursuant to a tech tip I read in Snowtech, I looked for the info, can't remember if it was SLP or POLARIS springs but definitely YELLOW, I sold the sled, still have the springs in my tool box.

Monte was trying to put something together on here reagarding a spring comparison chart.

Hope this helps.

Rich, good hear from you, glad to share the info.

Thanks for the 600 spring info, that's good to know, someone posted recently that ALL 600's used the same spring, so apparently that's not the case.

It's nice here on SnoWest, no a.j's

thefullmonte · Nov 22, 2009

Polaris has quite a few options, but since I can't unlock the file to post it I will just give you the popular ones. Springs are measured by Load/lbs @ 1" and Load/lbs @ .630". All the part #'s begin with 7041704-
-1 Blue 4 6
-2 Orange 5.5 8.3
-3 Pink 4.7 7.1
-4 Purple 3.1 4.7
-5 Yellow 2.4 3.6
-6 White 1.6 2.8

My memory is starting to come back to me with all this discussion.

The older 800 Pink spring worked good from 3-6000ft I believe and the yellow was for above that. However, keep in mind these are not the same motors. Let's keep each other posted on the results. I will be starting with the Pink spring in mine.

rockin rmk · Nov 22, 2009

After you remove and plug the hoses do you have to plug the exhaust valve also? Where the hose used to go.

thefullmonte · Nov 22, 2009

I'm going to remove the hoses and just cap the nipples coming off of the valves. I will post pics later tonight if I have time.

milehighassassin · Nov 22, 2009

rockin rmk said:
After you remove and plug the hoses do you have to plug the exhaust valve also? Where the hose used to go.

No you do not plug the exhaust valve. This is done so that the exhaust valve should function better.

Mandic · Nov 22, 2009

rockin rmk said:
After you remove and plug the hoses do you have to plug the exhaust valve also? Where the hose used to go.

Do you mean cap off the ports where the hoses go to the valves? In that case, yes you can do that. If you plug the hoses it is basically doing the samething. Most guys seem to be looking for the way to do it and make it look very stock.

Disconnecting the hoses and capping the valves won't appear stock, but it will work. In fact IMO it will work better. The less volume under the bellows the better. We all know air is more difficult to compress than liquid. So the more volume you add the longer it takes the pressure to build and actuate the valves. How much longer? I am sure in this case only milliseconds, but hey why not reduce the volume as much as you can?

And I was the one talking about 600 springs. I probably said right away that all 600s had the same springs, and that was an error on my part. But later I mentioned it REALLY depends on what model/year/engine you have. From my quick research in the parts breakdowns a RMK vs a 121" have different springs. CFI600 vs 600HO, different springs. So it really depends on what sled you have.

For me with an 08 Shift with a 600HO it has the same Pink springs as my Dad's 02 XC600. So for my 1500' riding situation, I think I am fine with just capping and running.

Boston Racing · Nov 22, 2009

I have a thought, If somebody wanted to do this would it be better to make a gasket for the powervalves that effectivly closes the exhaust vent hole. This would make it act like a regular powervalved motor as well as keep the oil from getting into the bellows. I am going to put a rubber vacuum caps on mine today and try it out. I have a 660 and I have the yellow springs in it riding at 7k and up.

On a side note, i cleaned mine today...Is it normal to have the underside of the bellows saturated in oil? When I took the valve off oil ran out of the tube.

milehighassassin · Nov 22, 2009

I don't think a gasket would work. I think the pressure would tear it open at some point.

Plugged Exhaust Valves?

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