oil injection delete

I've removed the oil injection on my sled. It's not a performace upgrade, apart from losing say 8-10 lbs. Sled runs just fine though if that's what you're getting at.

I haven't done it on my xp but have thought about it as I lost my motor at the end of last season due to the oil pump cable piling up. I did it back in my zx days and all that you had to do was remove the pump and run a block off plate and a small reservoir to lube the water pump. On the xp it appears that you have to run a line between the two fittings on the case that are fed by the pump and lube the waterpump also. I would like to know if the race sled ecm bracket works for the xp also? I don't mind premixing if I can cleanly remove the stock injection.

You can't get more reliable then premix.

I don't agree that running pre-mix in a snowmobile is more reliable . . . concider this - while decending a steep hill and you have the RPMs up to help slow you down and your not applying throttle the oil injection continues to lubricate the engine based on RPMs where premix relys on throttle position

It is true that the throttle cable increases the oil flow, but engine RPMs also increases oil flow. Regardless, your engine will see more lubrication in this situation than with premix.

And I guess we are all assuming that more is better? Also, just because oil is oozing on the crank case wall from the injector doesn't mean it is getting enough air/fuel to actually pick it up and lubricate the motor.

I did the delete because I wanted it to be more consistent and when I went in last time (because my tank cracked) I noticed the oiler cable had backed itself out considerably. I don't want to run it at 20:1 like it was set at a few years ago. I pre-mix at 40:1 and it seems to work great.

Rt

ReTodd said:

And I guess we are all assuming that more is better? Also, just because oil is oozing on the crank case wall from the injector doesn't mean it is getting enough air/fuel to actually pick it up and lubricate the motor.

I did the delete because I wanted it to be more consistent and when I went in last time (because my tank cracked) I noticed the oiler cable had backed itself out considerably. I don't want to run it at 20:1 like it was set at a few years ago. I pre-mix at 40:1 and it seems to work great.

Rt

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Ok but no . . that is exactly how the e-tech engine operates, only intake air and oil travel through the crank case. The fuel is injected directly into the combustion chamber and is never in contact with the oil. This is why the e-tech is such a clean burning engine, there is no fuel to wash the oil away.

snowcatter said:

Ok but no . . that is exactly how the e-tech engine operates, only intake air and oil travel through the crank case. The fuel is injected directly into the combustion chamber and is never in contact with the oil. This is why the e-tech is such a clean burning engine, there is no fuel to wash the oil away.

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The crank on the '07 & '08 800R has two sealed bearings and one semi-sealed bearing and is further lubricated by oil sitting in the bottom of the crankcase waiting to go through the oil pump. (That's why it's necessary to have a tube filled with oil on the two nipples at the bottom of the crank. Ensures oil is there to further lubricate the crank.) The '09 & '10 are the same except that there are three sealed bearings rather than just two. Either way, the crank is NOT lubricated by air/oil or air/oil/fuel as you suggest.

I can't say the same for the e-tech but I would assume this is the case.

At idle, the oil pump mixes approx. 80:1 (Don't quote me on that, as I can't remember the exact number and I'm too lazy to look it up). I believe it was Turboal who noted that it can take up to 5 seconds for the oil pump to catch up to the air/fuel mixture when starting from a dead stop (say idling before you climb a hill?!?!!?). Even at half that, that is far too long for the rings in the engine to be severely under lubricated. How many times does the engine fire in that period? At approx. 7,000 RPM that's about 300 times per cylinder in 2.5 seconds. Scary! Oil injection is conveniant, saves oil and burns cleaner, but I believe shows less engine longevity due to this condition.

30:1 is what I run which ensures my rings are well lubricated at all times, increases heat transfer from the piston to the cylinder wall (which reduces power fade due to over-heating), and is more reliable (but, of course, that's just my opinion).

As for oil injection providing more lubrication when going down hill, I have trouble understanding your rational there. If at full throttle your oil injection is set at 30:1 (many are set at 40:1, but we'll assume 30:1 here) then the only time you'd have even the same lubrication as someone with pre-mix would be when you are heading down hill at full throttle! Far from lubricating more, oil injection lubricates less than pre-mix.

Negatives to oil injection would be having to mix the fuel in the first place (kind of a pain!) and possibly fouling plugs if you allow the engine to idle for too long. Other than that, I think it's a must for anyone seeking to maximize engine performance.


Good Luck!

1200 miles in two season. I have my motor appart right now doing some RKtek stuff and everything is perfect. I mean Everything. I did it because something was up with my injections system. I would use almost a whole gallon in 9-10 gallons. Way Way to much oil.

I deleted my oil injection when I had my sled turboed. Its easy to mix gas and oil, why would you want to take the chance of the pump failing and smoke a $3000 motor.

I think what snowcatter is trying to say that when you are going down hill and the engine braking is engaged the throttle is closed, yet the rpms are high. In this situation if you are running premix you aren't getting much lube because the throttle is closed and no gas is entering the engine, thus no oil. He also is stating that in this situation with the oil injection that as rpms increase the oil pump will increase the amount of oil it is injecting to correspond with rpms, is this correct????

I thought the oil pump ran solely from the throttle cable pulling it open, and not from rpm's.

So if a guy wants to pull all the oil injection stuff off and run premix what is needed? it sounds like you remove the oil tank and lines. Then there are two nipples on the crank case that currently have hoses routed to the oil tank, and you still need to supply them with oil in case a seal goes out. Is this correct?

I like the idea of running pre-mix so i know exactly how much oil the engine is getting and run more oil, as all the stories of cables breaking etc... scare me.

Here is how oil injection works from a Society of Automotive Engineering paper from quite a few years ago. This was done by engineering students.

If my memory is correct they put radioactive markers in the injection oil to detect how long it took for the injection oil to travel through a two stroke and exit the pipe.

A high RPM engine, say 8000 rpm, might take a minute from the time the oil was injected to the time it exited the pipe while a lower rpm engine would take longer, maybe 1.5 to 2 minutes. It definitely was minutes not seconds!!!
It was a bunch longer than you would expect it to be!!!

So how does work real world on the side of the mtn? Your sitting at the bottom
of a climb waiting your turn to try for a high mark. Your sitting there for a few minutes, engine idling with the oil near shut off (100 to 1 or less) and it was near shut off when came down from your last climb. Your turn comes and finally your engine gets full rich oil for 30 seconds but your entire engine won't have the BENEFIT of full rich for a minute or two so you hit your turn around after 30 seconds and the oil is shut off again!!!

I don't like mixing oil but I like more power and longevity from premix and a free 10 lb weight loss on my XP.

As for more oil and power it makes more power. Aaen told me that 20 years ago on the dyno the more oil in premix the more HP on the dyno. Kevin Cameron also many years ago did a complete dyno workup on a dirtbike and had the same results. Downside is the spark plugs won't last as long.

Sidebar, on sparkplugs, discovered this many years ago on my Land & Sea Dyno, new plugs are almost always worth 1 to 5 HP no matter what they look like unless they are near brand new. Don't think there has been a quantum leap in the quality of NGK plugs in the past 15 years so I go through a lot of plugs. It was so bad if that if a customer wouldn't put in new plugs I wouldn't dyno his engine, just a waste of time!!! The worst I ever had before I really figured the sparkplug thing out and made that rule was a V-Max 4 that was missing on two of its four cylinders and because of its firing order couldn't hear it, was missing 25 HP!!!

Good Luck

gpr said:

I think what snowcatter is trying to say that when you are going down hill and the engine braking is engaged the throttle is closed, yet the rpms are high. In this situation if you are running premix you aren't getting much lube because the throttle is closed and no gas is entering the engine, thus no oil. He also is stating that in this situation with the oil injection that as rpms increase the oil pump will increase the amount of oil it is injecting to correspond with rpms, is this correct????

I thought the oil pump ran solely from the throttle cable pulling it open, and not from rpm's.

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I hear what you are saying GPR re: lubrication with the throttle closed. I am sure that the difference in crank lube would be the same as the two systems are virtually identical with or without the oil pump. The crank is lubricated by the sealed bearings and the oil sitting in the bottom of the crank case (via the two nipples at the bottom of the block)

Whether rods and rings would be as or more lubricated, honestly, I'm not 100% sure. I believe no oil would get up to the rings or the wrist pin unless it was mixed with fuel, but perhaps someone much more knowledgable could confirm or deny that.

I certianly see no obvious way that the oil pump would move oil into the cylinder or to the wrist pins to lubricate.

gpr said:

So if a guy wants to pull all the oil injection stuff off and run premix what is needed? it sounds like you remove the oil tank and lines. Then there are two nipples on the crank case that currently have hoses routed to the oil tank, and you still need to supply them with oil in case a seal goes out. Is this correct?

I like the idea of running pre-mix so i know exactly how much oil the engine is getting and run more oil, as all the stories of cables breaking etc... scare me.

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This is correct. Basically, remove the pump. Cover with a cover plate (same one as the 600RS engine found in the BRP parts catalog). Connect the two nipples with a small piece of hose. Connect an additional, larger hose filled with oil to a nipple near where the oil pump was. Fill with oil and zip tie upfairly high on the frame. Check periodically to ensure there is still oil there.


There is a thread on either here or possibly Dootalk on how to remove your oil injection complete with diagrams, pictures and part numbers. Check it out.

LRD said:

As for more oil and power it makes more power. Aaen told me that 20 years ago on the dyno the more oil in premix the more HP on the dyno. Kevin Cameron also many years ago did a complete dyno workup on a dirtbike and had the same results. Downside is the spark plugs won't last as long.

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I have also heard this and read papers on the affects of different premix ratio's. Basically (if my memory serves me correct) most 2 storke motors will gain power by adding more oil to the gas up until around 20:1 ratio. I personally prefer around 28:1 or 32:1 ratio. law of diminishing returns is in affect the closer you get to 20:1. Also you burn so much more oil and it coats your exhaust and almost drips out the exhaust at that rich of a ratio.

Many people think the opposite of this and want to run less oil and i have seen people run 2-strokes at 100:1 ratios. These same people typically go threw a lot of pistons, cylinders, and broken parts.....

I will have to search for those diagrams and pictures of the oil delete kits. If someone could point me to the post though, i would appreciate it so i know i'm hooking things up correctly

this thread has some pics of a guy who did oil injection delete on his XP.

http://www.snowest.com/forum/showthread.php?t=159262&highlight=oil+injection+delete&page=2

I did it on my 07 800R and think its great. I get to control what ratio i want to run and dont have to worry about the oil pump running at 20:1. You can get the XP race bracket for the starter handle and the small oil reservoir from the race model too, as well as the gasket and block off plate for where your oil pump was. I personally do not think you need a hose going through the block off plate like the guy did in the pics in that thread, I just took my engine out and filled the crankcase up with oil before putting the block off plate on.

the support bracket is #62 on the attached pic.

Evan