Tip on checking your power valves

tinkerjohnson · Jan 12, 2014

This is a tip on power valve gaskets on these 800 cfi engines, there are at least three different power valve gaskets that I have that will fit this engine and all three are different. This is for guys that have cleaned their power valves and replaced their gaskets if you put the wrong ones in the valves will not work properly. (found this out personally) some of the gaskets have the center hole cut to large and the power valve won't seal, you need to pay close attention to the power valve housing. The little round hole is not all that has to seal the housing has a larger longer hole that covers clear across to the other side to the other small hole. that larger oblonged hole has to seal to the cylinder or the pressure will not open the power valves properly the pressure will leak out in to the exhaust. the gaskets with the larger center hole do not seal properly and cause rpm issues on top end ( found this out personally) polaris has a new gasket now for this problem the hole in the center is a lot smaller I will post the part number tomorrow but I was having issues and found this and my sled runs better than ever now. I wanted to pass on this simple thing ( that most like me never even thought twice about) that causes runability issues. hope this helps others out there.

benltr · Jan 13, 2014

You clean them after how many hours of riding? 1 time a year or so?

Rmk_RDR · Jan 13, 2014

Do you have a part number?

dstrbdxpak · Jan 13, 2014

To note, the 11 and 14 have different PV gasket part numbers.

2011 - 2013 5812350

2014 - 5813934

gman086 · Jan 13, 2014

Please post comparison pics too if you can.

Thanks!

G

POLZIN · Jan 13, 2014

If you put anti-seize compound on them they will seal better and come right off and can be reused .

TRS · Jan 13, 2014

tinkerjohnson said:
This is a tip on power valve gaskets on these 800 cfi engines, there are at least three different power valve gaskets that I have that will fit this engine and all three are different. This is for guys that have cleaned their power valves and replaced their gaskets if you put the wrong ones in the valves will not work properly. (found this out personally) some of the gaskets have the center hole cut to large and the power valve won't seal, you need to pay close attention to the power valve housing. The little round hole is not all that has to seal the housing has a larger longer hole that covers clear across to the other side to the other small hole. that larger oblonged hole has to seal to the cylinder or the pressure will not open the power valves properly the pressure will leak out in to the exhaust. the gaskets with the larger center hole do not seal properly and cause rpm issues on top end ( found this out personally) polaris has a new gasket now for this problem the hole in the center is a lot smaller I will post the part number tomorrow but I was having issues and found this and my sled runs better than ever now. I wanted to pass on this simple thing ( that most like me never even thought twice about) that causes runability issues. hope this helps others out there.

My hat is off to you sir.
Here is what I found today. Two different gaskets in the shop. A real eye opener.

tinkerjohnson · Jan 13, 2014

TRS said:
My hat is off to you sir.
Here is what I found today. Two different gaskets in the shop. A real eye opener.

Yes that's exactly what I was getting across them pics show the difference thanks trs

tinkerjohnson · Jan 13, 2014

Part numbers
5812350 is the old number
5813934 is the new part number
5812925 is the number that will not work but will fit
I believe at the dealer they are changed to the new number. The gasket that won't work is the cfi 700 gasket

tinkerjohnson · Jan 13, 2014

TRS said:
My hat is off to you sir.
Here is what I found today. Two different gaskets in the shop. A real eye opener.

Trs could you take a pic of the valves without the gasket in place so guys can see the oblong hole that needs to seal. thanks man for the visual aids very helpfull mine is all together now

TRS · Jan 13, 2014

tinkerjohnson said:
Trs could you take a pic of the valves without the gasket in place so guys can see the oblong hole that needs to seal. thanks man for the visual aids very helpfull mine is all together now

I'll get it up tomorrow, just got home from the snowmobile club meeting.

LoudHandle · Jan 13, 2014

Summary?

Just for clarification; gasket part #5813934, which is the bottom gasket in the middle photo from TRS is the preferred gasket. The one with the close tolerance center cut out is the best fit for the 800 CFI-2's. Correct?

TRS · Jan 13, 2014

LoudHandle said:
Just for clarification; gasket part #5813934, which is the bottom gasket in the middle photo from TRS is the preferred gasket. The one with the close tolerance center cut out is the best fit for the 800 CFI-2's. Correct?

The bottom one in the center picture is the correct one.

tinkerjohnson · Jan 13, 2014

LoudHandle said:
Just for clarification; gasket part #5813934, which is the bottom gasket in the middle photo from TRS is the preferred gasket. The one with the close tolerance center cut out is the best fit for the 800 CFI-2's. Correct?

Yes use that part number (5813934) the pics are the other two I mentioned that part number the gasket is even smaller hole in the center than the ones pictured but so there are two that will work but the one with the largest hole will not seal correctly ( his picture does not show the new gasket (8513934) just the old part number that will work and the the one that won't work hope this makes sense

tinkerjohnson · Jan 13, 2014

Also the new part number gaskets that I got are made of a yellow color material not gray like the others. This may or may not be on all gaskets but the new ones I got were, this may help with identification also

TRS · Jan 14, 2014

tinkerjohnson said:
Trs could you take a pic of the valves without the gasket in place so guys can see the oblong hole that needs to seal. thanks man for the visual aids very helpfull mine is all together now

Here it is.

Rmk_RDR · Jan 14, 2014

This could be the reason why 2 weeks ago in Cooke I couldn't get my valves to stay open on long pulls in 3 feet of pow thanks for posting this!

LoudHandle · Jan 14, 2014

Thanks to all contributors!

Yes, Thanks to all the contributors! The pics make it obvious why the large center cut out gaskets do not work. Thanks to all for their enlightenment and contributions to the subject.

I know I will be swapping all mine over to the new gasket, gasket part #5813934, ASAP to avoid any runnablity issues.

geo · Jan 14, 2014

I don' know as much about these motors as some but I learned a lot last year and more this fall and some more just now lol.
The 3934 grey ones came stock in the '13's and I bought a pair of them early for servicing. The next 4 I bought last spring were the tan ones. They don't seem to last as long.

I'm pretty in touch with my motor and the one issue that re-occurred was with the exhaust valves and the Poo system with them.
After about 5 to 600 miles I would start to notice variable peak rpm, loss in power and it made me look. Looked for piston-ring issues but wasn't there for me but I always pulled the valves to check too (PITA).
First time was just a cleaning, new gasket and all was good. Second time was lighter springs, new gasket, 28 dollar thing and all was good. Third time was a head scratcher (only 400 miles) but found the fitting on the exhaust side of the solenoid was loose, new gaskets and all was good.

4th time was this fall to freshen things up. Under 300 miles but my gaskets here were leaking already.
What happens in my motor (Yamalube at 32 to 1, pretty dirty oil but I like it) is carbon builds on this spot from exhaust gases and the seal only happens when the valve slams against it. So carbon and valve contact shreds the one side until it can't seal here.
I coated new gaskets with 1211 Bond and let it cure before installing to see if it would help but this thread made me add 1 plus 3 together.
This should be a stainless, coated gasket (like Suzuki or the base gasket on our motors) and I bet my ex. valve probs would not reoccur.
I think I will make some 30 thou aluminum gaskets before my next valve service (when r's become inconsistent) and try them.

Good post.

gman086 · Jan 14, 2014

FWIW Carl's stocks the Cometic ones which are the correct profile - same as in the lower pic (just checked mine). Mine came labelled on receipt as 5812350 for my 2011 and cost only $7.18 for a pair.

Have FUN!

G MAN

Tip on checking your power valves

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