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Fianlly found my Sluggish and No top end Power valve problem!

Here's my orignal post:


2011 Pro uses alot of fuel. Could it be an injector problem?

--------------------------------------------------------------------------------

My 2011 Pro RMK feels like it's down on power and it seems to be using quite a bit more fuel than it use to!
It has just over 1000 miles.

This is what it does:
It revs pretty quick to about 6800 then is sluggish, it dosent bog but still continues to rev to about 7500 then picks back up to 8000-8100.

Plugged the exhaust valve hose and it seemed to help the sluggishness but still uses more fuel.
I cleaned the exhaust valve hoses and ports going into the cylinders!
Confirmed that the exhaust solenoid valve is working.
Plugs do look rich!
Checked plug wires and all other wiring for wear causing it to short out. Found none.
Clutching is all good.
Replaced the pipe EGT sensor, no change?
It has the yellow injectors in it.
Could the injectors be causing this?

------------------------------------------------------------------
Ok here's the new post:

Ok, this is what I found:
It was an Exhaust Valve problem! The small ports inside the Pwr Valve bodies were plugged!

This is how I found it: (After going over just about everything else!!!!) This is the quick way!

With the hood off!
Remove the Hose from the Pwr Valve side of the Solenoid. (It’s a bitch getting it off the plastic barbed fitting. Be careful not to break the fitting!) Were bypassing the solenoid for now.

To confirm that the Pwr Valves are free and working. Use compressed air at about 3 to 5lbs only
Blow into the hose. Watch the hole on the plastic caps of the Pwr Valves. You should see the end of the Pwr Valve shaft move up in to sight. Release the air pressure and they should pop back outa sight.
Ok, if they move freely then move on.
If not? Take them out and clean at this point then jump straight to the end.

OK, they moved freely.
Start the sled, let it idle. No need to put the hood back on!
Look to see if any smoke or anything comes out of the hose! There should be some smoke puffing out, especially if the sled is cold!!! Some kind of air flow for sure! If there is or there isn’t move on.

OK, now let’s see if they function with the engine doing the work!
Plug the hose. (With the sled on a jack stand) rev it up full throttle. Watch the hole in the pwr valve cap to confirm the valves are opening or not. (Same as above using the compressed air)
The sled will probably not want to rev out to 8000 but give it as much as it will go.

Did the Valves move in to sight the same as they did with the air?
Mine did not! AW HA! No pressure getting to the Pwr Valves to open them!
Where are they plugged??

Remove the Pwr Valves and clean everything. (See the attached pictures)

Also clean the port coming from the cylinder. They get plugged too! Be sure to clean them all the way into the cylinder. The holes are larger most of their depth then get smaller just before they break into the cylinders. Remove as much crap as you can then BLOW OUT THOROUGHLY!!!
If there is a loos piece of crud left in there? It will get blown into the Pwr valve body and plug the small port again!!

Take a look at the pictures. Hope fully they will show you were to clean the Pwr valve body ports! They are pretty small ports and easy to miss!

I personally don’t like Polaris Power valve operation design allowing the exhaust gasses to flow through the valves until the solenoid closes! All the time the exhaust is flowing through it just lets carbon and gunk build up inside!
On the 800R Ski-doo. It uses the crank case to supply a clean source of Vacuum or Pressure to operate their Pwr valves using Check valves! Works pretty good!

2 Small Hole Location.jpg 2 Small Hole Location-1.jpg Cleaning Small Port with Wire.jpg Exhaust Inlet port to Pwr Valve.jpg Exhaust Inlet port to Pwr Valve-1.jpg Exhaust port on Cylinder.jpg Exhaust port on Cylinder-1.jpg
 
VERY nice write up! I've been battling performance issues all season. I have already done my change for the week and am testing it out shortly but if it's back to the shop then this will be the next thing I do FOR SURE!
 
towny, what type of oil do you use and how many miles on the machine?

thanks for the write up, btw.
 
Here's my orignal post:


2011 Pro uses alot of fuel. Could it be an injector problem?

--------------------------------------------------------------------------------

My 2011 Pro RMK feels like it's down on power and it seems to be using quite a bit more fuel than it use to!
It has just over 1000 miles.

This is what it does:
It revs pretty quick to about 6800 then is sluggish, it dosent bog but still continues to rev to about 7500 then picks back up to 8000-8100.

Plugged the exhaust valve hose and it seemed to help the sluggishness but still uses more fuel.
I cleaned the exhaust valve hoses and ports going into the cylinders!
Confirmed that the exhaust solenoid valve is working.
Plugs do look rich!
Checked plug wires and all other wiring for wear causing it to short out. Found none.
Clutching is all good.
Replaced the pipe EGT sensor, no change?
It has the yellow injectors in it.
Could the injectors be causing this?

------------------------------------------------------------------
Ok here's the new post:

Ok, this is what I found:
It was an Exhaust Valve problem! The small ports inside the Pwr Valve bodies were plugged!

This is how I found it: (After going over just about everything else!!!!) This is the quick way!

With the hood off!
Remove the Hose from the Pwr Valve side of the Solenoid. (It’s a bitch getting it off the plastic barbed fitting. Be careful not to break the fitting!) Were bypassing the solenoid for now.

To confirm that the Pwr Valves are free and working. Use compressed air at about 3 to 5lbs only
Blow into the hose. Watch the hole on the plastic caps of the Pwr Valves. You should see the end of the Pwr Valve shaft move up in to sight. Release the air pressure and they should pop back outa sight.
Ok, if they move freely then move on.
If not? Take them out and clean at this point then jump straight to the end.

OK, they moved freely.
Start the sled, let it idle. No need to put the hood back on!
Look to see if any smoke or anything comes out of the hose! There should be some smoke puffing out, especially if the sled is cold!!! Some kind of air flow for sure! If there is or there isn’t move on.

OK, now let’s see if they function with the engine doing the work!
Plug the hose. (With the sled on a jack stand) rev it up full throttle. Watch the hole in the pwr valve cap to confirm the valves are opening or not. (Same as above using the compressed air)
The sled will probably not want to rev out to 8000 but give it as much as it will go.

Did the Valves move in to sight the same as they did with the air?
Mine did not! AW HA! No pressure getting to the Pwr Valves to open them!
Where are they plugged??

Remove the Pwr Valves and clean everything. (See the attached pictures)

Also clean the port coming from the cylinder. They get plugged too! Be sure to clean them all the way into the cylinder. The holes are larger most of their depth then get smaller just before they break into the cylinders. Remove as much crap as you can then BLOW OUT THOROUGHLY!!!
If there is a loos piece of crud left in there? It will get blown into the Pwr valve body and plug the small port again!!

Take a look at the pictures. Hope fully they will show you were to clean the Pwr valve body ports! They are pretty small ports and easy to miss!

I personally don’t like Polaris Power valve operation design allowing the exhaust gasses to flow through the valves until the solenoid closes! All the time the exhaust is flowing through it just lets carbon and gunk build up inside!
On the 800R Ski-doo. It uses the crank case to supply a clean source of Vacuum or Pressure to operate their Pwr valves using Check valves! Works pretty good!

my friend found the same thing with his.

I put vacuum caps on my barbs so the solenoid opens and closes and does nothing and the exhaust valves open and close by vacuum like the old ves edge motors.
 
towny, what type of oil do you use and how many miles on the machine?

thanks for the write up, btw.

I bought the sled used and the guy was using the VES Gold Plus!
Gave me what was left of most of a gallon when I bought it.

The sled was used for his business which was environmental consulting for mining companies so he needed it to get back in the mountains were the mines are located. It had 930 miles on it. I think most of the miles had to be road miles because the hyfaxes were completely shot!!! I now have 1300 on it!
I ride it in the steep and deep so put a lot more load on it. I assume it was gummed up from not running it hard once in a while?? Just a guess!!

Anyway, I've been chasing the bad fuel mileage and loss of top end performance for a while and have been glued to Snowest and other sites looking for answers! This was a tuff one to find!
Was almost ready to admit defeat and take it to the dealer but gave it one last shot to try and find the problem!

I think I'm going to take the hoses off the Pwr Valves and just let them lay, then buy a short piece of hose and connect both valves together.
This way, If one valve should should start to plug it will still get pressure from the other to activate the valves! This will leave the solenoid hooked up but by passed and can re-hook it up quickly if needed?

I've read were people suggesting not to do this but I'll give it a try. If it keeps the valves from plugging up it may be worth it!
 
Last edited:
I think I'm going to take the hoses off the Pwr Valves and just let them lay, then buy a short piece of hose and connect both valves together.
This way, If one valve should should start to plug it will still get pressure from the other to activate the valves! This will leave the solenoid hooked up but by passed and can re-hook it up quickly if needed?

I've read were people suggesting not to do this but I'll give it a try. If it keeps the valves from plugging up it may be worth it!

i'm currently running a 5/16" bolt on the hose between mine. i suppose what you're looking to do would be similar to taking vise grips and clamping off the hose that runs down to the solenoid. a lot of folks try that just to see what gains they are getting before they plug the system.

maybe someone else has a little more info on leaving the two hoses connected between the valves?
 
I think I'm going to take the hoses off the Pwr Valves and just let them lay, then buy a short piece of hose and connect both valves together.
This way, If one valve should should start to plug it will still get pressure from the other to activate the valves! This will leave the solenoid hooked up but by passed and can re-hook it up quickly if needed?

I've read were people suggesting not to do this but I'll give it a try. If it keeps the valves from plugging up it may be worth it!


Excellent write up! :yo:

I inquired about disabling the EV control circuit earlier this season & received mixed responses.............

It seems that some have had good luck simply plugging the EV vent circuit while others have gone so far to as to experiment with different compression springs & even alter the size of the supply port coming from the cylinder..............Then on the other side of the coin some that have tried this mod., have experienced detonation............

It would appear that any machine that is modded & possibly running leaner than normal A/F ratios will be prone to detonation with the EV vent/pilot control circuit plugged..............

The only way to know for sure is to try it & see what happens..............
 
In picture number 4 you have a nice shot of the two small port holes in the upper half of the gasket. Those gasket holes are SMALLER than the actual holes in the exhaust valve assembly so... gunk accumulates there and you wind with the problems you experienced. The solution is to take an Exacto blade and cut the gasket holes larger -simple as that. Carl's turned me on to that trick; they actually sell modified gaskets with the bigger port holes so thanks to them! But yeah, do need to clean the ports out of the exhaust valve assembly too when doing the maintenance.

Have FUN!

G MAN
 
Last edited:
Great write up.

I might add that cleaning the all the rubber hoses on each side of the solenoid, and cleaning the solenoid itself is crucial as well.

And I have also noticed that the plastic elbows on both sides of the solenoid come loose, and don't hold pressure on the engine side. I replace those plastic 90's each time, clean the threads of the solenoid and add high temperature Copper RTV, for a good seal.
 
I would also check the black hoses that come from the solenoid, a year or two ago someone had a "turd" like piece of oil residue in one of there hose's.
 
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