LoudHandle's Unbiased findings on the stock Polaris Oil Cap
First I'll tell you my test parameter's; Tank / guard assembly removed from sled, Oil reservoir neck sleeve installed, leveled right to left, blocked up to the same incline as it is on the sled. I did it in the kitchen with the blocking on the microwave for a comfortable working height and good lighting. For measurement purposes I used my Ratio-Rite. Ambient temp was 65 degrees F. I did a minimum of 4 repeatable runs, at 45 seconds each (using the timer on the microwave), noting the flow for each time period, but only pulling the cap and recycling after the fourth run. I confirmed that the individual runs and the average of the 4 runs were within a few ml (Ratio-Rite reads in CC's but they are the same thing) of each other. My test oil was Legend ZX2SR. Tank filled to the bottom of the fill neck and recycled after four flow test runs.
I started with the no cap flow test and my repeatable average was 140 ml, over the eight runs.
I then ran all 3 of my Geo Goretex style modified caps they all averaged 117 ml, over the 4 runs each.
I then inverted the whole thing to check permeation thru the three 0.020" holes, break thru and first drop of oil took 3 1/2 minutes.
I then again verified flow with the Cap cavity saturated with the trapped oil, somewhat surprisingly it flowed 125 ml, over the four runs.
I then melted one hole shut and repeated the flow test on that cap now with two holes, it still flowed 115 ml, over the four runs.
Melted an additional hole shut for a one hole test, flowed 103 ml, over the four runs.
I then melted the final hole shut (simulated stock cap) and confirmed TRS findings and subsequent subtlety's that were posted in subsequent posts.
The stock cap flowed well for the first 20 seconds, in the last 25 seconds I observed a series of 10 drips.
The first run only delivering 25 ml over the entire 45 second span.
The second run only delivered another ten drips. The third, 4 drips; and the fourth run, 3 drips.
To confirm the observation and confirm repeatability; I ran the four runs again and it was indeed repeated.
I then ran it again; but shook it like a can of spray paint between the second and third run. It flowed nearly 50 ml on each of the third and fourth runs. As the sled will not handle being shaken like a rattle can continuously.
I refilled the tank and set it up again. I ran the first run and got the normal 25 ml and flow stopping after 20 seconds, ran the second run and got the ten drips. I then knocked it off the blocks (a 2" drop to a hard surface of the microwave). Which is still harder than a properly tuned suspension would allow. Possibly one with blown shocks, and bottoming hard. This is where I found this most interesting.On the two following runs it flowed 100 ml, each. I reset the tank and ran another run and all four runs it flowed 100 ml, each.
So in conclusion; the stock cap can stick both open and closed.
Open would be a good thing; other than the rare occasion when you end up inverted for a length of time.
If it should stick closed; you are only getting about 20 seconds worth of oil and then starving the pump. Do you want to ride a sled and make sure you take a hard hit every 20 seconds? To ensure there is an oil supply to the injection pump?
You all can make up your own mind on the stock cap, and how to fix it. If you are not convinced yet that there is an issue; I encourage you to conduct your own little test. I was skeptical a year ago much like Oregon sledder and voiced my disbelief like he is. I now have the proof I needed to form my opinion.
I know, I value my riding partners and I's, riding days too much to leave my fate to whether the stock cap decides to function properly. To me any of the alternatives is far cheaper than the humiliation of F'n up a riding day with my peers. I will be at a minimum drilling one 0.020" hole in my caps and if that is still too messy, I will likely go for the clean and cheap BRP cap.
First I'll tell you my test parameter's; Tank / guard assembly removed from sled, Oil reservoir neck sleeve installed, leveled right to left, blocked up to the same incline as it is on the sled. I did it in the kitchen with the blocking on the microwave for a comfortable working height and good lighting. For measurement purposes I used my Ratio-Rite. Ambient temp was 65 degrees F. I did a minimum of 4 repeatable runs, at 45 seconds each (using the timer on the microwave), noting the flow for each time period, but only pulling the cap and recycling after the fourth run. I confirmed that the individual runs and the average of the 4 runs were within a few ml (Ratio-Rite reads in CC's but they are the same thing) of each other. My test oil was Legend ZX2SR. Tank filled to the bottom of the fill neck and recycled after four flow test runs.
I started with the no cap flow test and my repeatable average was 140 ml, over the eight runs.
I then ran all 3 of my Geo Goretex style modified caps they all averaged 117 ml, over the 4 runs each.
I then inverted the whole thing to check permeation thru the three 0.020" holes, break thru and first drop of oil took 3 1/2 minutes.
I then again verified flow with the Cap cavity saturated with the trapped oil, somewhat surprisingly it flowed 125 ml, over the four runs.
I then melted one hole shut and repeated the flow test on that cap now with two holes, it still flowed 115 ml, over the four runs.
Melted an additional hole shut for a one hole test, flowed 103 ml, over the four runs.
I then melted the final hole shut (simulated stock cap) and confirmed TRS findings and subsequent subtlety's that were posted in subsequent posts.
The stock cap flowed well for the first 20 seconds, in the last 25 seconds I observed a series of 10 drips.
The first run only delivering 25 ml over the entire 45 second span.
The second run only delivered another ten drips. The third, 4 drips; and the fourth run, 3 drips.
To confirm the observation and confirm repeatability; I ran the four runs again and it was indeed repeated.
I then ran it again; but shook it like a can of spray paint between the second and third run. It flowed nearly 50 ml on each of the third and fourth runs. As the sled will not handle being shaken like a rattle can continuously.
I refilled the tank and set it up again. I ran the first run and got the normal 25 ml and flow stopping after 20 seconds, ran the second run and got the ten drips. I then knocked it off the blocks (a 2" drop to a hard surface of the microwave). Which is still harder than a properly tuned suspension would allow. Possibly one with blown shocks, and bottoming hard. This is where I found this most interesting.On the two following runs it flowed 100 ml, each. I reset the tank and ran another run and all four runs it flowed 100 ml, each.
So in conclusion; the stock cap can stick both open and closed.
Open would be a good thing; other than the rare occasion when you end up inverted for a length of time.
If it should stick closed; you are only getting about 20 seconds worth of oil and then starving the pump. Do you want to ride a sled and make sure you take a hard hit every 20 seconds? To ensure there is an oil supply to the injection pump?
You all can make up your own mind on the stock cap, and how to fix it. If you are not convinced yet that there is an issue; I encourage you to conduct your own little test. I was skeptical a year ago much like Oregon sledder and voiced my disbelief like he is. I now have the proof I needed to form my opinion.
I know, I value my riding partners and I's, riding days too much to leave my fate to whether the stock cap decides to function properly. To me any of the alternatives is far cheaper than the humiliation of F'n up a riding day with my peers. I will be at a minimum drilling one 0.020" hole in my caps and if that is still too messy, I will likely go for the clean and cheap BRP cap.
Last edited:
