oil injection delete
- Thread starter maxwellzx
- Start date
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.
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.
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.
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
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?
L
LRD
Well-known member
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!!!!
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!!!!
Great debate going on here...but would someone post instructions for phuks sake!
....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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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
Should you cap off the old brass oil nipples that go into the case? I would think you would need to or you could lose vacuum for the Raves and DPM.
Rt
Rt
