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oil injection delete

S

sledsrock

Well-known member
Nov 26, 2007
1,826
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Grand Junction, Co.
Correct me if I'm wrong here, but you may need to drill the case for the PTO and MAG bearings to allow oil to the bearing with premix, I do know on a 2004 800HO, when deleting the oil injection that is what is highly recommended.
 

byeatts

Well-known member
Premium Member
Nov 29, 2007
3,403
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Correct me if I'm wrong here, but you may need to drill the case for the PTO and MAG bearings to allow oil to the bearing with premix, I do know on a 2004 800HO, when deleting the oil injection that is what is highly recommended.
No The oil injector is simply 2 small holes[Brass injectors} on the cases. Oil sprays/drips down the inside of cases and the Air/fuel turbulance is what picks it up to lube bearings. Premix does a far better job since the mixture is allways consistant, Plugs are cleaner and motor will run crisper and you will loose weight.
 
I now have a question, seeing as the rotax motor is NOT a case reed motor, some of the air does not ever see the bottom end, would this starve the bottom end of oil? With the injectors being right in the bottom end, I would be led to believe that the crank sees more of the injected oil versus pre-mixed. Obviously many people have removed the oil injection without problems, but something to think about!

You do save quite a bit of weight if you run the oil tank all the way full on your sled like I do, but you can get almost the same weight reduction by only running a quart of oil in your oil tank and not the full gallon.
 

byeatts

Well-known member
Premium Member
Nov 29, 2007
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Funny you say that, when I had my crank rebuilt, the guy who did it said that they used to drill and tap the case to drip premix oil down into the bearings INSTEAD OF running isoflex grease. I never did it, but you reminded me of it!
The Fuel /air mixture gets forced into the crank cavity by the piston action,It does a much better job lubeing the bottom end, And nobody would chance only running 1 quart, I have seen a few only fill half way but most fill the oil.Granted that will help the weight concerns only a bit.
 
C
Nov 26, 2007
276
7
18
When you take off to ride your sled is at least 8 lbs lighter. Tell us how much a gallon of oil weighs? -oil pump.and plastic. I can tell you, I weighed it and many others who have done this mod can tell you as well, You however have Not done this and should just keep quiet,Since you have not completed this mod , This consistant perfect feul /oil ratio helps an engines life as well.You do not need a reservoir just a clear inspection tube.Your fuel tank is full with premix instead of just gas.and that it! How much $ does it cost in after-market goodies does it take to lose 8 Lbs?.

You say that I have not done this mod. and then go on to attack my point of view. Yes, I have done this mod. I have been modding sleds sence before you were born.
Like I said. Start the day with 1/2 gallon less fuel and 1/2 less oil in your tank. You will get the same results as an oil delete. That is 6 lbs right there.

I didn't say that there were not advantages to a delete kit. I simply stated that by deleting the oil injection system, you are just starting the day with less fuel in the tank and less oil to start the day.

1/2gallon of oil is 4 lbs. 1/2 gallon of fuel is 4 lbs. 4+4=8lbs. Same as the delete.
Cost of this mod. $0
 
M

maxwellzx

Active member
Oct 16, 2008
613
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if you run your oil low if your sled is on its side isnt there a good chance you could get an air bubble in your line and possibly vaccum lock the system ?
 
The Fuel /air mixture gets forced into the crank cavity by the piston action,It does a much better job lubeing the bottom end. QUOTE]

Yes, but Rotax motors are packed with grease and sealed. The PTO/Mag side bearings never see oil conventionally! They were drilling and tapping a hole in between the two bearings, and allowing oil to drip into the cavity, then the oil would just pass through the inner oil and be burned up through the motor. Every doo motor I have ever pulled apart that ran grease needed more by the time I broke them down, maybe the constant feed of oil would increase the life of the cranks? maybe not? Has anyone ACTUALLY tried this? experiment?:D
 
L

LRD

Well-known member
Mar 27, 2002
572
135
43
I'm seriously thinking about eliminating the isoflex on my longtrack TNT. The oil injection delete was near 10 lbs according to my 50 lb digital fish scale. I used a clear fuel filter with guts removed for a tank. Also came up with a super lightweight solution for the plastic cup for the starter handle, just bolted to the side panel with black nylon license plate bolts.

My reasons for oil injection delete

1. 9.5 lbs + weight loss

2. A SAE study years ago measured how long it takes for oil to travel through an engine. Can take a minute or longer depending on high of RPM, so your sitting at the bottom of the climb waiting your turn, oil injection is basically turned off and you hit it, about the time you have finished your climb and head back down you might or might not have full rich oil ratios going through your entire motor.

Good Luck with that!!!!
 
M

maxwellzx

Active member
Oct 16, 2008
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if i get my parts soon i will take some photos and make a little tutorial on my website
 

byeatts

Well-known member
Premium Member
Nov 29, 2007
3,403
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You say that I have not done this mod. and then go on to attack my point of view. Yes, I have done this mod. I have been modding sleds sence before you were born.
Like I said. Start the day with 1/2 gallon less fuel and 1/2 less oil in your tank. You will get the same results as an oil delete. That is 6 lbs right there.

I didn't say that there were not advantages to a delete kit. I simply stated that by deleting the oil injection system, you are just starting the day with less fuel in the tank and less oil to start the day.

1/2gallon of oil is 4 lbs. 1/2 gallon of fuel is 4 lbs. 4+4=8lbs. Same as the delete.
Cost of this mod. $0
First of all I have done this MOD, I have sleds with and without injection systems,Perhaps you should read more clearly. Second.LRD indicates even more weight loss,9.5 lbs and is correct on better engine performance And third i,m 48 year old and if you have been doing this mod before I was born,Well I wont address that, Have 25 years of Mountain riding as well. For flatlander riding the weight may not be as noticeable or as important.I just cant see why one would choose to have the additional weight and the only advantage to injection is the absense of premixing. I,m always looking for that edge and 8+ pounds is a real good start.
 
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R
Nov 27, 2007
1,258
747
113
Cantaffordus, WA
www.mbhc.net
Like I said. Start the day with 1/2 gallon less fuel and 1/2 less oil in your tank. You will get the same results as an oil delete. That is 6 lbs right there.
1/2gallon of oil is 4 lbs. 1/2 gallon of fuel is 4 lbs. 4+4=8lbs. Same as the delete.
Cost of this mod. $0

No offense but you must be from Minnesota. I suppose if I wanted to only fill my sled with 5 gallons of gas I could save even more weight but I ride only mountains and starting the day with 1/2 full oil reservoir is CRAZY!!! Not a good idea where we ride.

Rt
 
C

cog

Member
Dec 7, 2007
99
9
8
Here's how I mounted the bottle, etc. I run 32-1

p8280003.jpg


oilpumpremoval.jpg
 
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i'llDooit

Well-known member
Nov 27, 2007
2,486
812
113
Duvall washington
Nice!!!! so does that oil circulate? Or not really. the level in that tank should never change correct.? Then i see the 2 brass fittings still,,,,, are the plugged?
 
M

maxwellzx

Active member
Oct 16, 2008
613
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shouldnt you only need a feed tube going into the top fitting? or is this a your way to get some sort of circulation.
 
C

cog

Member
Dec 7, 2007
99
9
8
There's no cir, oil leval should change very little, just the way I did it.
 
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