OIL RATIO DISCUSSION ON THE 800 CFI MOTORS

I run 32:1 premix. I saw an article that showed no decrease in performance down to around 16:1, if I remember correctly. 32:1 is an easy mix at any gallonage-4oz/gal.


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ELI... are you talking about running this on a 800 CFI motor equipped with the factory oil injection pump?

Can you dig up that article that you saw?

Also Some thing to keep in mind.. When adding more oil..


Isn't Kinda going Leaner... More Oil.. Same Gas.. . In the same Burn Chamber.. ?????


Also.. For the steady throttle guys.. Bumping up the oil pump is nice security..

But the ones that ride it like they stole it Kind. Throttle is to the bars! And moving.. not keeping it at one speed.

Keeping on key.. here..

Yes, Could use a little more oil.. But not much.. this Oil is getting$$$$$$$$$$$$$$$$.. I think i went through 6 Gals in 1600 Miles.. When i think that way... That's a season of riding for $330 in oil $650 in Fuel

mountainhorse said:

ELI... are you talking about running this on a 800 CFI motor equipped with the factory oil injection pump?

Can you dig up that article that you saw?

Click to expand...

I'm looking on the net for it....it was an older test.


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http://www.bridgestonemotorcycle.com/documents/oilpremix6.pdf

Here is one, not the exact one I was thinking of......

Here is a quote on a three-wheeler forum regarding oil.....

Pre-mix ratios and power production

I have run Dyno tests on this subject. We used a Dynojet dynamometer, and used a fresh, broken in top-end for each test. We used specially calibrated jets to ensure the fuel flow was identical with each different ratio, and warmed the engine at 3000 rpm for 3 minutes before each run. Our tests were performed in the rpm range of 2500 to 9000 rpm, with the power peak of our test bike (a modifed '86 YZ 250, mine) occuring at 8750 rpm. We tested at 76 degrees F, at 65% relative humidity. We started at 10:1, and went to 100:1. Our results showed that a two-stroke engine makes its best power at 18:1. Any more oil than that, and the engine ran poorly, because we didn't have any jets rich enough to compensate for that much oil in the fuel, and the burn-characteristics of the fuel with that much oil tended to be poor. The power loss from 18:1 to 32:1 was approximately 2 percent. The loss from 18:1 to 50:1 was nearly 9 percent. On a modern 250, that can be as much as 4 horsepower. The loss from 18:1 to 100:1 was nearly 18 percent. The reason for the difference in output is simple. More oil provides a better seal between the ring and the cylinder wall.

Now, I realize that 18:1 is impractical unless you ride your engine all-out, keeping it pinned at all times. But running reasonable ratios no less than 32:1 will produce more power, and give your engine better protection, thus making it perform better for longer.


As a side note, I no longer run 26:1, I now run 32:1. I'm not a young man any more, and I just can't push as hard as I used to, so I don't need as much oil now. 32:1 is enough oil to do what is needed for me now, since I'm getting slow..

I wonder what the thermal content, in BTU's/Lb (or the metric equiv)... of a given gasoline and a given oil is mixed at say 4 different ratios... 50:1 , 40:1 , 30:1 , 20:1

Ring seal is not something that I considered...but the bore size, stroke, ring velocity/acceleration and thickness.. bore material, ring material would also have an effect on the output. So for this conversation... we'll keep it to the Stock CFi 800 engine so we don't get side-tracked.

More oil for ring sealing might balance out less thermal content of an oil/fuel mix. HMMM...















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Eli said:

Here is a quote on a three-wheeler forum regarding oil.....

Pre-mix ratios and power production

I have run Dyno tests on this subject. We used a Dynojet dynamometer, and used a fresh, broken in top-end for each test. We used specially calibrated jets to ensure the fuel flow was identical with each different ratio, and warmed the engine at 3000 rpm for 3 minutes before each run. Our tests were performed in the rpm range of 2500 to 9000 rpm, with the power peak of our test bike (a modifed '86 YZ 250, mine) occuring at 8750 rpm. We tested at 76 degrees F, at 65% relative humidity. We started at 10:1, and went to 100:1. Our results showed that a two-stroke engine makes its best power at 18:1. Any more oil than that, and the engine ran poorly, because we didn't have any jets rich enough to compensate for that much oil in the fuel, and the burn-characteristics of the fuel with that much oil tended to be poor. The power loss from 18:1 to 32:1 was approximately 2 percent. The loss from 18:1 to 50:1 was nearly 9 percent. On a modern 250, that can be as much as 4 horsepower. The loss from 18:1 to 100:1 was nearly 18 percent. The reason for the difference in output is simple. More oil provides a better seal between the ring and the cylinder wall.

Now, I realize that 18:1 is impractical unless you ride your engine all-out, keeping it pinned at all times. But running reasonable ratios no less than 32:1 will produce more power, and give your engine better protection, thus making it perform better for longer.


As a side note, I no longer run 26:1, I now run 32:1. I'm not a young man any more, and I just can't push as hard as I used to, so I don't need as much oil now. 32:1 is enough oil to do what is needed for me now, since I'm getting slow..

Click to expand...

Eli,

1. On the 800 CFI is it possible for me (my Mechanic)to set the oil pump delivery ratio to 32:1?

2. Is there a specific setting on the oil pump for this ratio I can have my mechanic set it to or is it hit or miss?

Easy.. Way to Do this kinda.. is Figure Out What your Ratio is now.. All in Theory...

Fill Oil Bottle Mark.. Fill Fuel.. Using same gas and oil.. Also the same pump. at gas station too!

Hopefully ride.. "Normal" As you ride normally... If you ride different.. Harder.. This making Your Ratio Lower, with increasing throttle / wide open.


Then Fill back up.. and Measure.. Oil Used/Gas used.. say one Quart.. per 10 Gal.. is 40:1...


Hope that helps..

Also Need to adjust oil pump.. about 3-4 turns on nut. .. Richer.

Which is a pain in the butt!.. Just takes time.. This also being why most people Don't change it.... Make it some thing to do when your in there already.. !!! Hit two bird with one stone!

Kinda... The oil pump is a variable delivery pump...

The oil pump control arm is attached to the throttle control by a linkage rod on the PRO DC-CFI-2.

A misconception is that the injection pump on a Polaris 2-stroke delivers a leaner fuel/Oil ratio at lower RPM's.

The Polaris pump is a variable output pump, controlled mechanically by throttle position, so that the ratio stays constant (for the most part).

At low RPM's (less throttle opening)... the injectors are delivering a lower volume of fuel...therefore less oil is needed to maintain a given ratio.

Conversely at high RPM's (more throttle opening)... the injectors are delivering a higher volume of fuel... therefore more oil is needed to maintain a given ratio.

"setting the oil pump" is possible... there is an adjustment on the oil pump linkage rod at the throttle bodies to allow you to turn up the volume by having the oil pump initial setting open more... this will "index" the pump delivery up, which will deliver more volume at all RPM's... keeping a fairly constant ratio as before.

I'll see if I can post a pic of this page in the manual... I only have a print version of this.

There is no way, other than the method described by Matt to tell what that ratio is... it is trial and error.. and getting to that adjustment screw takes some time (pull fuel tank out, remove air box)

I also want to add one point.

IF YOU DO NOT KNOW WHAT YOU ARE DOING AND HOW THE SYSTEM WORKS... DO NOT ADJUST THE OIL PUMP... YOU COULD TURN IT THE WRONG DIRECTION AND ACTUALLY CAUSE YOUR FUEL/OIL MIXTURE TO BE LEAN AND DAMAGE THE ENGINE!!

According to the warranty in your owners manual... Adjustment of the oil pump by anyone other than a factory authorized service center, to factory specifications, would void the warranty.












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Eli said:

I run 32:1 premix. I saw an article that showed no decrease in performance down to around 16:1, if I remember correctly. 32:1 is an easy mix at any gallonage-4oz/gal.


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Click to expand...

thats a little deceiving, Agreed no performance loss for the test however after running 500 mile at 32-1 i now get building carbon in Y pipe which slowly robs performance. My jetting is on the leanish side as well,using egt,s also.switched to SRF oil which has more of complete burn,Been trying in the KTM in slow single track conditions and it has no spooge and is burning better.

Eli said:

Here is a quote on a three-wheeler forum regarding oil.....

Pre-mix ratios and power production

I have run Dyno tests on this subject. We used a Dynojet dynamometer, and used a fresh, broken in top-end for each test. We used specially calibrated jets to ensure the fuel flow was identical with each different ratio, and warmed the engine at 3000 rpm for 3 minutes before each run. Our tests were performed in the rpm range of 2500 to 9000 rpm, with the power peak of our test bike (a modifed '86 YZ 250, mine) occuring at 8750 rpm. We tested at 76 degrees F, at 65% relative humidity. We started at 10:1, and went to 100:1. Our results showed that a two-stroke engine makes its best power at 18:1. Any more oil than that, and the engine ran poorly, because we didn't have any jets rich enough to compensate for that much oil in the fuel, and the burn-characteristics of the fuel with that much oil tended to be poor. The power loss from 18:1 to 32:1 was approximately 2 percent. The loss from 18:1 to 50:1 was nearly 9 percent. On a modern 250, that can be as much as 4 horsepower. The loss from 18:1 to 100:1 was nearly 18 percent. The reason for the difference in output is simple. More oil provides a better seal between the ring and the cylinder wall.

Now, I realize that 18:1 is impractical unless you ride your engine all-out, keeping it pinned at all times. But running reasonable ratios no less than 32:1 will produce more power, and give your engine better protection, thus making it perform better for longer.


As a side note, I no longer run 26:1, I now run 32:1. I'm not a young man any more, and I just can't push as hard as I used to, so I don't need as much oil now. 32:1 is enough oil to do what is needed for me now, since I'm getting slow..

Click to expand...

Qoute" Not a young man anymore! Crap your 40 and soon as I finish my nap I should teach you a lesson

Here's a pic I took of my '09 700 RMK's oil pump and the alignment marks. I haven't seen a Pro's oil pump but figured this may help. The alignments marks are moved by tightening or loosening the cable adjuster nuts thus changing the amount of oil injected into the engine.

Same thing on the PRO... but the cable was replaced by a linkage... the adjuster is now on the throttle body.

I just got this back from Jim at Dyno tech after I sent him a query and link to this thread... I guess we will see some good info soon on this.

Testing it down to 20:1... Thanks Jim!!!

I'll plan to do an oil ratio dyno test, so we can try to determine the actual difference in HP by adding more injected oil. My guess is that any difference will be minimal, plus or minus. But let's see what the dyno says. Thanks Jim

Click to expand...

This is interesting and one of those questions we get almost daily. In all the riding, racing and dyno thrashing we've been involved in over the last 15 years or so, there is one thing I can tell you for sure, most any two stroke will live longer, seal better and as a result make better power with more oil than less within reason. whats the number? in our shop, 32:1 on bores 81mm and larger, 40:1 on the smaller stuff. The difference, in our opinion, mainly due to the longer heat path on the bigger bores.

Now, if you are running 32:1 in say a 700 twin or larger engine and are getting carbon build up in the manifold to the point that it affects power out put...you are way off on the rest of the engine calibration or the ignition is failing. I've yet to see a properly calibrated modern two stroke sled engine that won't be happy on a 32:1 mix--all the statements about the oil leaning out or richening up the fuel mixture do not apply to the engines we are discussing here (unless you go off the deep end as stated above...16:1 etc).
If we were discussing chainsaws or weedwackers my opinion would change drastically due to the tiny bore sizes involved and several other factors.

Don't think I'm just spouting here, just relaying real world experiences that have turned into gospel in my shop.

As far as the CFI engines go, I agree fully with MH and his opinions about the current oiling situations being EPA related (the past and current poor fuel and timing curves also). It has been our experience that you can definitely increase the oil pump delivery AND WE RUN OIL IN THE FUEL TANK ALSO. We have never and do not expect to ever see any negative issues from this, the exhaust valves do not "carbon up" more, neither do the exhaust ports or manifolds AS LONG AS THE REST OF THE TUNE IS PROPER!

By the way, that bit of extra oil doesn't effect your injection system either-contrary to some popular belief/internet rumor.

Now, I'm not going to tell anyone which oil to run-never have. I care much more that you run enough of it. The guys that complain about having to buy and use more oil in their sled than their buddies "brand -x " uses will not leave my shop happy 'cause we'll likely set them up to use even more. If ya can't afford to pay, you shouldn't be playing!

Folks, the internals of our modern engines really aren't much more refined (if at all) than sled engines of 15 years ago so what makes you think that the oil requirements are different?

one last point of discussion/interest. I look for an oil that leaves the exhaust port and sometimes even the manifold a little oily--not dry and crispy. This tells me that the oil has survived the brutality of the engine internals and survived. When I see oils that turn into layers of carbon cooked onto the port wall, I shy away from it. The current OEM mixtures and many oils are producing these results in the CFI engines (among others)

Again, just our real world experiences here--no science, just brutal testing over a lot of years.


For example:

We take an 1160cc triple in a hydroplane, a two stroke powered vehicle that goes through every extreme of abuse you can imagine-literally. dead idle trolling for minutes to the point of 200+ degree cooling temps, then immediate 5-7 minutes WFO at full load--WAY more sustained load than a sled will ever be capable of, then troll it back into shore as the water cavities empty and water jacket temps skyrocket again. as the jackets empty out we are left with steam inside the engine, cooking the internals and covering them in moisture...now she sits for 2 or more hours like this, then we dump it back in the water cold, pop it off and do it all over again, and again...oils and oil ratios that keep these engines alive for season after season are a-OK in my book.

IMO, those that constantly search for magic oil to allow them to continue to run poor tunes, improper clearances or ill matching parts are barking up the wrong tree.

We've seen countless engines make killer power and live very very long lives on both cheap and expensive oils, find the right one for you and your sled and use enough of it...yours will do the same.

Curt

I agree, when I ran 2.5 drag mercs, 13,500 rpm at 225 cranking compression the more oil the better, we always ran about 25:1 redline cart oil and VP C14 + never any issues. I always run extra as premix in my sleds.

There are some pretty smart people on this forum. Thanks for the info.

Doesn't Polaris recommend running pre-mix for the first tank? If not, and I wanted to run 32-1 from the start, what would be a safe bet amount of oil to add to the first tank?