S
How big of a hole are you guys drilling? Or whos making vented caps?
13 800 just went down 1700 miles
- Thread starter keithw
- Start date
I can understand the breather hole getting plugged with belt dust and other crap and essentially creating a situation where oil can't be "sucked" out by the pump. The tank needs to breathe for the pump to work normally. I'd be interested to see an oil cap that's been modded with additional holes to allow more venting so if the primary hole gets plugged there's a backup or 2.
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Is the primary hole in the cap or elsewhere?
Sounds like something that should be added to the maintenance checklist.
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Scott- my apologies. My phone corrected "modded" to "molded". It should have been modded. I'd need to look at the cap. I thought there used to be a little ball in the cap but can't remember. Maybe I'm thinking of my old Cat.... But that may be an option if cat has one that works with the same threads, etc.....
Hole is in the middle of the cap, there is a ball in it. They are pretty much the same as a cat I have read. I vented my tank and oil use increased.
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Take ur oil cap in ur hand and hold it perfectly level breather hole facing straight up. Now put ur mouth on it and blow some air through. While continuing to blow ( head NOT in gutter here) slowly tilt the cap sideways. Mine blocks up with only about 10 degrees of tilt. Considering that the cap is mounted on the oil tank at a slight angle, I think the cap vent is closed more often than not. Hence my $2.50 custom made and installed vent line.
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G
Something maybe easier (did it to my '12 PC and my Pro) is drill 3 tiny holes (get a cheap tip cleaner drill kit from a welding place and use the 15 thou bit) on the underside of the cap.
Kinda the Gortex theory of air can pass through but not oil. Works for me.
Kinda the Gortex theory of air can pass through but not oil. Works for me.
I respectfully differ in the "oil cap" theory.
The oil is not used at an fast rate...all it needs is an occasional "hiccup" of air entering the oil bottle to equalize pressures ambient/internal.
The cap is designed, on purpose, NOT to vent even at a slight angle.
If it opens for a split-second just once every 15min.. that's enough.
With help from gravity, and the fact that the pump has some suction... the oil bottle would have to be puckered inward to the point that you would hear a huge sucking noise when you removed the cap for the air to get sucked in past a hose connection or fitting.
The same cap, same oil pump has been used for years... The caps function has not changed.
Sure it is possible to have a defective cap that never vents OR to get some dirt in there if your sled is filthy and you never clean your clutches/belt/sled i guess... but I've seen plenty of horribly filthy 900's with the same cap (and same way it functions).
In fact, on my Dragon... I had a plugged vent on the cap from letting it sit in the shop, upside-down, for a couple of months over the summer when I forgot to put it back on... when I did and ran the sled.. and added gas on the hill end of day, I got that serious "swish" of air as I opened the cap... A good cleaning and it gave me another 2 years of service.
If it were running like a garden hose... or even a fuel tank... a higher rate valve (like the unit on the fuel tank) would be needed.
If you regularly run the tank low on oil and, at the same time, have a super steep left side lean/side hill... or flip the sled and leave it running... air can easily enter the line as the suction fitting becomes the high spot, sitting in free air, in the oil-tank. Keep the oil tank at the full mark at each fuel tank fill up.
And don't take my post the wrong way... I acknowledge that it is possible to get the rare oil tank cap that does not function, just not very likely.
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The oil is not used at an fast rate...all it needs is an occasional "hiccup" of air entering the oil bottle to equalize pressures ambient/internal.
The cap is designed, on purpose, NOT to vent even at a slight angle.
If it opens for a split-second just once every 15min.. that's enough.
With help from gravity, and the fact that the pump has some suction... the oil bottle would have to be puckered inward to the point that you would hear a huge sucking noise when you removed the cap for the air to get sucked in past a hose connection or fitting.
The same cap, same oil pump has been used for years... The caps function has not changed.
Sure it is possible to have a defective cap that never vents OR to get some dirt in there if your sled is filthy and you never clean your clutches/belt/sled i guess... but I've seen plenty of horribly filthy 900's with the same cap (and same way it functions).
In fact, on my Dragon... I had a plugged vent on the cap from letting it sit in the shop, upside-down, for a couple of months over the summer when I forgot to put it back on... when I did and ran the sled.. and added gas on the hill end of day, I got that serious "swish" of air as I opened the cap... A good cleaning and it gave me another 2 years of service.
If it were running like a garden hose... or even a fuel tank... a higher rate valve (like the unit on the fuel tank) would be needed.
If you regularly run the tank low on oil and, at the same time, have a super steep left side lean/side hill... or flip the sled and leave it running... air can easily enter the line as the suction fitting becomes the high spot, sitting in free air, in the oil-tank. Keep the oil tank at the full mark at each fuel tank fill up.
And don't take my post the wrong way... I acknowledge that it is possible to get the rare oil tank cap that does not function, just not very likely.
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K
Did you try shaking the cap while blowing on it? I know when I ride, even on flat trails, my sled is vibrating and shaking like crazy. I have a hard time believing that the ball in the cap isn't vibrating and bouncing around just like the sled and I am over every bump. Not to say the cap doesn't cause a problem here or there, but Polaris is not going to risk having a $4,000 engine get replaced on warranty because of a venting issue with a oil cap. If a $10 cap didn't work and was causing melt downs, they would change the design.
My oil usage before my cap/vent modification was approximately 55/1. Calculated with 3 days of riding in McCall.
My oil usage after my cap/vent modification is now approximately 30/1. Calculated with the next 3 days of riding in McCall.
No adjustment was made to the oiler. The only changes other than the oil cap modification that were done between each cycle of 3 day ride was:
Add oil and gas.
I have had the same results on my wifes Assault and my old Dragon not to mention the other sleds that I have done this for and all have reported close to the same results.
This was the only way I could keep the air bubble from returning in the Dragon.
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G
MH, sometimes s**t happens then you just remember and do it.
Your theory is sound but,,, if you fill the tank it decreases air volume. If you turn up your pump it displaces more volume. How much vacuum will it take before that tiny outlet (smallest ID in the supply system at a very poor angle IMO) doesn't flow. If it doesn't flow for a bit and a bubble happens for a bit, does that bubble at full throttle get down to the pump (like when you bleed a new machine) and vent the air to the same outlet line every time? If the bubble gets "stuck" in that outlet line is the pump strong enough to push it out at part throttle (path of least resistance, have you never had a "sticky" bubble on an outlet line during PDI). How many times does this POSSIBILITY have to happen until that particular oil outlet area MAY experience lack of oil multiple times.
Did Polaris ever think this bubble after the tank was an issue? Yes. Did any other manufacturer ever have a venting problem in their oil tank because of the same cap? Yes. Their cure was a sticker to keep the oil level low to add air volume and then later models came at a different angle with the sticker.
MAYBE nothing will ever happen to you but I experienced the problem in '12 and lost the Mag side on my engine at 1200 miles. I had bled the pump as per special instructions and even took the time to remove the stupid 3" 90 at the outlet (bigger ID than Polaris tank). Pump was good. Never saw a bubble when I checked. But a long walk is something I won't forget.
These special instructions were issued after failures at dealerships (people who should be looking for this) during PDI. Some were in the field with no definite answer. Later came the volume bulletin with the sticker.
Nobody proves anything here no matter how bold you type lol. To say it can't happen is WRONG. But true or not, when your out in the boonies it's nice to cover all the bases YOU can.
Do it or don't do it. It's really up to the individual isn't it. I've never had an oil cap that did not function as it was designed but I will always do the drill thing from now on.
Your theory is sound but,,, if you fill the tank it decreases air volume. If you turn up your pump it displaces more volume. How much vacuum will it take before that tiny outlet (smallest ID in the supply system at a very poor angle IMO) doesn't flow. If it doesn't flow for a bit and a bubble happens for a bit, does that bubble at full throttle get down to the pump (like when you bleed a new machine) and vent the air to the same outlet line every time? If the bubble gets "stuck" in that outlet line is the pump strong enough to push it out at part throttle (path of least resistance, have you never had a "sticky" bubble on an outlet line during PDI). How many times does this POSSIBILITY have to happen until that particular oil outlet area MAY experience lack of oil multiple times.
Did Polaris ever think this bubble after the tank was an issue? Yes. Did any other manufacturer ever have a venting problem in their oil tank because of the same cap? Yes. Their cure was a sticker to keep the oil level low to add air volume and then later models came at a different angle with the sticker.
MAYBE nothing will ever happen to you but I experienced the problem in '12 and lost the Mag side on my engine at 1200 miles. I had bled the pump as per special instructions and even took the time to remove the stupid 3" 90 at the outlet (bigger ID than Polaris tank). Pump was good. Never saw a bubble when I checked. But a long walk is something I won't forget.
These special instructions were issued after failures at dealerships (people who should be looking for this) during PDI. Some were in the field with no definite answer. Later came the volume bulletin with the sticker.
Nobody proves anything here no matter how bold you type lol. To say it can't happen is WRONG. But true or not, when your out in the boonies it's nice to cover all the bases YOU can.
Do it or don't do it. It's really up to the individual isn't it. I've never had an oil cap that did not function as it was designed but I will always do the drill thing from now on.
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I was always under the assumption that the red race oil was for premix applications only, not designed for injection use...........
I have been wrong before and may be again.............
Eric, after reading Dave's post I'm beginning to think there is something to the venting, or the lack thereof, in some of the caps out there. Mine being one of them possibly?
My oil injection pump cranked to the max.(one thread of the adjuster showing above the jam-nut) & having tracked my oil & fuel consumption over the course of 400-ish miles last season I was pretty well where Dave was before his mod - 55:1.
I can't say that I've ever noticed a vacuum release when I've opened the lid before but I also can't help but wonder how some people are able to get ratios of up to 32:1 while I'm only able to get 55:1.
G
Since day one, with a drilled cap and a thread or less still showing, I burn 32 to 28 to 1 out of the tank. Depends on the thumb and I rarely break 8150.
Before sculpted bodywork tank caps were flat.
Before sculpted bodywork tank caps were flat.
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I heard that exact sucking noise when I twisted my oil cap off last year and watched oil drain partially down the empty line (Thread: 2011 RMK 800 Burnt Down Again) after melting the top end in the Snowies. You make good points, and I'm not saying its common, but literally for the two bucks it cost me to vent the tank, I'll do it on every sled I ever get.
I actually think that it only takes a "small" amount of oil to get in the cap and it will lock it, the stickiness or something.... now do most customers have their sled layin flat on its back 10-20 times a day? Probably not.
G
Just through the bottom "cone" RMS. One tiny hole is probably enough but I do three lol.
I got about another 1300 on the Cat and never saw a drop come out the cap. Have had a pretty dang poor season this year for many reasons but over 2100 miles total now and not a drip out of the cap on the Pro. I do "fall over" quite a bit too lol.
I would be inclined to think the same as what MH posted (too simple, been here forever, the sky is falling "not") except for my experience in '12 and Cat's answer. The oil entering the caps venting system seemed to be the cause. If the cap never sits flat maybe the oil never drains. So a sticker was included in the "update" kit lol. Hope they didn't spend too much.
I never fill my tanks to the top anyway but I do "fall over" a lot. The Poo tank is an awesome 2 chamber design. First time I looked at it made me realise the engineers were not just bolting on parts on this package. Coulda made the oil tank lighter.
The reason I looked at it and scratched my head for a while is because of the threads on SW I read about the air bubble. How does it even get there with this tank design? Some bled and it returned, some bled and it didn't return, some said it isn't a problem.
MAYBE it comes up from the pump and not down from the tank if supply is restricted. Cavitation can create air. Check valves are know to leak at times. I don't know and never did figure it out but since I did my PDI (dealer gave me the sled with a full tank and a bubble lol), bled the pump, and vented the cap I have never had a bubble.
When the venting kits and oil cap threads started popping up this year I just smiled because I was done. It's funny how experiences can add to the "have to do list" for a new to you sled. More "experiences" and the longer the list lol.
That's a whole other thread though with probably lots of "fun" stories.
I got about another 1300 on the Cat and never saw a drop come out the cap. Have had a pretty dang poor season this year for many reasons but over 2100 miles total now and not a drip out of the cap on the Pro. I do "fall over" quite a bit too lol.
I would be inclined to think the same as what MH posted (too simple, been here forever, the sky is falling "not") except for my experience in '12 and Cat's answer. The oil entering the caps venting system seemed to be the cause. If the cap never sits flat maybe the oil never drains. So a sticker was included in the "update" kit lol. Hope they didn't spend too much.
I never fill my tanks to the top anyway but I do "fall over" a lot. The Poo tank is an awesome 2 chamber design. First time I looked at it made me realise the engineers were not just bolting on parts on this package. Coulda made the oil tank lighter.
The reason I looked at it and scratched my head for a while is because of the threads on SW I read about the air bubble. How does it even get there with this tank design? Some bled and it returned, some bled and it didn't return, some said it isn't a problem.
MAYBE it comes up from the pump and not down from the tank if supply is restricted. Cavitation can create air. Check valves are know to leak at times. I don't know and never did figure it out but since I did my PDI (dealer gave me the sled with a full tank and a bubble lol), bled the pump, and vented the cap I have never had a bubble.
When the venting kits and oil cap threads started popping up this year I just smiled because I was done. It's funny how experiences can add to the "have to do list" for a new to you sled. More "experiences" and the longer the list lol.
That's a whole other thread though with probably lots of "fun" stories.
O
Like MH I'm not convinced the venting can be much of a difference. I have a few of these caps laying around my shop. I will drill one and leave my stock cap untouched. I will run a tank of gas with each and monitor oil usuage. We will see.