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SKI DOO OIL TANK CAP... A $14.99 alternative

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Members on here seem to rarely post on stuff that works... and focus on stuff that needs attention.

I have them on 4 sleds so far.... 2 older doos, a 900 RMK, and a Pro RMK... All with Zero issues....These caps are super simple, and use a duckbill valve that has no moving parts.

TRS... the member that brought this topic up... He is THE MOST thorough "sled guy"/wrench/engineer that I know of... I put my faith in this and his use of them on all of his sleds


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The ski Doo cap requires a minimum vacuum to open up the duckbill, the spinning oil pump provides this vacuum.

I have the Ski Doo cap installed on all four of our Pros.

The oil pumps are turned up so we burn approx 4oz per gallon (32:1) we also add 1oz per gallon.
 
To verify that the green duckbill valve was manufactured correctly; pinch the end or distort it slightly and verify that it has a split in the end and opens up. That will ensure it will open under a slight vacuum and work as designed, and avoid an issue like TinkerJohnson described in his post.

My guess is his never got the split put into it or it was stuck shut for whatever reason.

You should also verify that are the new one that has the green duckbill, because the Skidoo cap that preceded the vented one looks identical from the top.
 
Bought a skidoo cap for my pro today. Dealer even had it in stock. If it blows up after today at least I can rule out oil starvation
 
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Ran this oil cap for numerous years on my Pro. Oil consumption increased with it on compared to the OEM cap. I would recommend it to anyone running a Pro.
 
Ran this oil cap for numerous years on my Pro. Oil consumption increased with it on compared to the OEM cap. I would recommend it to anyone running a Pro.



With all the different caps posted in this thread. A definition of your explanation of " this cap" would be great........
 
Ski Doo oil cap

Anyone running a Ski Doo oil cap have an issue that over the Summer being the oil cap won't create a vacuum the oil seeped into the motor. I mean alot of oil like a couple cups. This happened to me two years in a row now. I would suggest to put the stock oil cap on for storage.
 
There are 5 check valves that deliver the oil from the pump to the case and it sounds like these (one or more) could be leaking! Had this happen in the past on more than one sled. These check valves can be checked with a mighty-vac using the pressure function and they should open the check valve at about 3-6 psi, If they are leaking, need to clean and try again or replace it as I have had to do in more than one time in the past.
gtwitch in wyoming
 
By the way , I am running the Doo caps on all of our Pros with no problems (3 years now).
 
I have sold my pro now or I would dig into it. I'm sure having the doo cap on made the situation worse than it would have been with the stock cap. Thanks for your input!
 
There are 5 check valves that deliver the oil from the pump to the case and it sounds like these (one or more) could be leaking! Had this happen in the past on more than one sled. These check valves can be checked with a mighty-vac using the pressure function and they should open the check valve at about 3-6 psi, If they are leaking, need to clean and try again or replace it as I have had to do in more than one time in the past.
gtwitch in wyoming

^^^^^^^^^ had it happen also. Replaced 2 check valves and all is well. It was using a ratio of 12:1 VES.
 
I have sold my pro now or I would dig into it. I'm sure having the doo cap on made the situation worse than it would have been with the stock cap. Thanks for your input!

I'm sure you would have found it was the check valves and not the cap. In storage you should be able to leave the cap off and not get oil seepage. The cap needs to vent in order to allow the oiling system to work properly. Isn't that the reason why you put it on in the first place? The stock cap isn't designed to create a vacuum in the oil tank although there is a theory that in operation it is doing that in some situations. Thanks for bringing up the topic though as I'm sure others will run into this too.
 
Anyone running a Ski Doo oil cap have an issue that over the Summer being the oil cap won't create a vacuum the oil seeped into the motor. I mean alot of oil like a couple cups. This happened to me two years in a row now. I would suggest to put the stock oil cap on for storage.

A nifty trick for summer storage is to loosen the cap a few turns so it can vent the pressure that is caused by the warm temperatures. Best to tape your key to the oil cap so that you don't fire it up in the fall and leak oil all over your belt on your first ride of the year.
 
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