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2021 fuel map

G
Jan 21, 2008
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Wabush NL, Canada
Got 2 full days on my 2020 Khaos that was flashed a couple of weeks ago. We just had a week long snowstorm and finally have some great snow to ride in. This thing works better than it ever has. It flat out rips without a hiccup. I also noticed that the hanging idle that I used to have while picking my way around in the trees is pretty well gone. Fuel and oil consumption is about the same as before. Overall I am very happy with this thing!
 

Track Man

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Dec 24, 2007
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Coppins Meadow
Just put my new Boondocker 61gram weight on. What a difference. I started out with #6 capsule. Turn 8600. #8 capsule 8400 +. #10 Capsule and it’s going 8350 and settle at 8250 all day long. My sled is now running perfect. I highly recommend these weights. Only takes a minute to change a capsule.
 

gopher-it!

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Nov 28, 2007
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Just put my new Boondocker 61gram weight on. What a difference. I started out with #6 capsule. Turn 8600. #8 capsule 8400 +. #10 Capsule and it’s going 8350 and settle at 8250 all day long. My sled is now running perfect. I highly recommend these weights. Only takes a minute to change a capsule.
What elevation?
 

Track Man

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Dec 24, 2007
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Coppins Meadow
I am at 7000 here at the house. I might have to go to the smaller Capsule when I get to 8000+. The new map and 91 non-ethanol setting. Seems to be starting a lot better after warmed up. We just got 2 feet of fresh snow And more on the way. Up top it’s going to be deep. I’ll be able to get some good testing done now
 

Mentzel

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Oct 10, 2009
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The problem is the oil injection method and rate. Usage is around 26:1 on 20/20 map. The electronic pump is not manually adjustable like the Cleanfire 800. The Patriot 840 oil pumping rate has to be corrected in ecu map since it is all electronic.

Polaris went from 65:1 on CF800, (barely used any oil so we were turning up the pumps).

to ~26:1 on Patriot 840. Holy cow too much! smokey..dawg

The target range for the past 30 years has been 40-50:1. It just seems to work great in 2 strokes 500-1000cc range.

The 840 oil injection method now targets specific bearings to oil and the fuel injector is in the transfer port/s. So you can’t just pre-mix gas and oil like old engines to fix.

To be clear there is nothing wrong with VES Extreme oil. You just can’t inject it at 26:1.. Its going to foul plugs all day long.

The VES Gold oil is more tolerant to heavy oiling rates. I’ve used it in racing engines for over 20 years in all brand engines including BRP. It just works!

The CF800 with stock oil pump setting will work great with Extreme oil. It injects at half the rate so extreme oil works great in that engine!

The work around for the 840 is hotter plugs and VES Gold oil. BPR8ES plugs. (solid top).

Also do not overlook the spark plug caps. Once they start arcing replace them. (plug top will look shiny and a little melted at pin spots.) This will cause the cylinder drop feeling when you hit bumps.
 
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Spiderman

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Dec 1, 2007
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How the heck are they meeting emission standards with that high of an oiling rate? You would think with electronically controlled it would be a breeze to get close to a 50 to 1 through the whole power band.
 

Mentzel

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How the heck are they meeting emission standards with that high of an oiling rate? You would think with electronically controlled it would be a breeze to get close to a 50 to 1 through the whole power band.



It feels like we are going forward with tech but backward (all at the same time)..

This comes from trying to follow BRP etec and emissions standards. Polaris needs to stop dooing that.. Stick with what works especially if the tech is not quite 100% yet

Start at 50:1 total oiling rate for VES Gold. Bump to 60:1 for VES extreme.

Make the tech gadget electronic oil pump do that! Right now the oil injection rate is not even in the proper zip code.
 

Spiderman

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Dec 1, 2007
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Measure your oil / measure your gas usage. Post it.
I agree that its too rich... you can feel it especially in the low end. I just don't get how it passes emissions at that ratio and why they are struggling so much getting a final tune in it.
 

Sheetmetalfab

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Oct 5, 2010
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……..
I agree that its too rich... you can feel it especially in the low end. I just don't get how it passes emissions at that ratio and why they are struggling so much getting a final tune in it.

I think they don’t have a high enough resolution in the engine management software/ hardware combo.

This causes the system to be too erratic to catch all the variables that affect a 2 stroke.

Hence the reason the N/A 850 for 2022 has a completely different engine management system...........
 

Mentzel

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Oct 10, 2009
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I was baffled by the lack of oil wash out in the crankcase when this engine first came out. I figured shoot new tech they got it figured out.. inject very little oil right on bearings and it will work fine. (Like etec.)

Then blamo 26:1 rate! Plenty of oil now. geez.

If oiling the crank bearings at a very high rate.. What stops the oil from simply puddling in the crankcase? Then a splash up once in a while into the transfer ports will foul a plug.

Premixed engines or injector mixed engines never had this sort of problem.
 

Mentzel

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Oct 10, 2009
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Anyone got some oil? I’m running low from last weekend.. dang it! #empty

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A
Nov 26, 2007
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Elko, NV.
Had a different experience with the '21 map this last weekend, lately it has taken 3 to 6 pulls to start when warm requiring a little bit of throttle to fire. This last weekend it was 55 degrees on the mountain and my sled fired first pull on 8 different occasions (never done this before). It looks as though fuel delivery needs to be a tad richer at startup. How is the 21.5 map starting?
 

MKULTRA

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Dec 31, 2015
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quebec, canada
How the heck are they meeting emission standards with that high of an oiling rate? You would think with electronically controlled it would be a breeze to get close to a 50 to 1 through the whole power band.
why on earth would they run a fixed ratio anyway? why isn't it tuned to RPM and throttle opening?
 

Solby

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Nov 26, 2007
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Colfax, WA
I went from the 20.5 to the 21 flash last week. Hot starts were greatly improved. Most of the time it started first pull. A couple times it took multiple pulls and once I had to hold it WOT and pull 8 times to get it going. Overall it is better but dang Polaris please figure it out already.
 

Mentzel

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Oct 10, 2009
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I’m starting to think we would be better off with a red dixie cup and sharpie marker for mixing oil and a can of starting fluid to get-R cranked up..

Then at least we know who to blame if she blows!
 

Mentzel

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Oct 10, 2009
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I think they don’t have a high enough resolution in the engine management software/ hardware combo.

This causes the system to be too erratic to catch all the variables that affect a 2 stroke.

Hence the reason the N/A 850 for 2022 has a completely different engine management system...........

Boost is the reason for new engine management. Now they have a lot more parameters to monitor and conditions to map in ecu.

I hope they didn’t bite off too much to soon with the new boosted engine.

Crankcase injectors spraying a constant oil mix rate (percentage of fuel rate) seemed right to me; like the old CF-4.

But mapping 4 injectors on that engine was problematic also.

I don’t see the big advantage of a transfer port mounted fuel injector since it only injects fuel at that location. So now there is no fuel wash in crankcase. If so the oil would eventually clean out and engine run clean.

Since there is no gasoline wash in crankcase the oil injection rate and locations better be spot on injecting bare minimum, (like etec does) or oil will puddle and cause major tuning problems.

wasting time even thinking about fuel mapping until oiling is correct.

now you have boosted pressures..? yikes
 

NHRoadking

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Is there a consensus on why Polaris cannot get the mapping right on the 840? It seems like the fixes are haphazard.

Are there changes to the 2022s to address these issues?
 
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