The Oil Delete Thread

JHG

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There have been several threads on here talking about the BDX oil delete. Some people feel that crank issues have been caused by the oil delete and some people have had many trouble free miles. I had an opportunity in get inside a 2008 M1000 motor this last weekend and thought that I would share my findings and some pictures that would help people decide if the oil delete was right for them.

A quick note before I start, this motor did not have an oil delete when we started and was not torn down because of any issues with an oil delete.

This is a picture of the bottom of the crankcase, looking at it from the rear(opposite of where the oil pump would go). The hole in the middle of the case is where the stock oil pump injects oil directly into the case. When using the BDX oil delete, they give you a screw to plug this hole when you remove the oil pump.



And a closer picture, center right is where the plug goes.


If you look at the other side of the case with the crank removed, you will see that the hole I previously mentioned is under the shaft that operates the water pump.



You can also see in the above picture where the 4 crank bearings sit, and the water pump shaft is directly between the middle 2 bearings. Here is a picture with the crank sitting in the case.



This is a picture of the top of the case, you can see there there is no passage for fluid to pass from the outside of the inner crank bearings to the inside. The transfer ports you see are on the outside of the seal and only provide oil to the crank bearings. The two lines you see between the ports are where the seal rests.




As far as the 4 crank bearings go, there is no difference in the amount of oil they receive in an oil injected motor or a premixed motor. The oil is injected behind the throttle bodies and the oil gas mix is then brought into the case. This is the same thing that happens in an premixed motor, the fuel/oil is just mixed earlier. You can see in the picture with the crank in the case that the oil injected into the case underneath the water pump shaft can not exit that cavity to get to any of the crank bearings. The inter bearings have a shield that is not ported. So the 4 crank bearing are not the issue with the oil delete.

However, because the oil injected in the case can not escape the cavity to lube the crank bearings, the opposite is true of the premix getting to the water pump shaft. When you remove the pump, the water pump bearings receive no lubrication from the premixed fuel. There are a couple of solutions to this problem, one is to install a line to the hole where the oil injection used to inject oil in the case and manually inject oil in there every few rides, or you can drill the case and install a line to provide an oil/gas mix to the water pump shaft. BDX uses an injected bushing on the delete kit that they supply so one end of the pump shaft is okay, but the other end that goes through the case is where the problem lies. We decided to drill the case, I'll show pictures of how that was done in case someone is wanting to do there's this way.

We used these parts off the old oil pump. The brass fitting connected to the hose is a one way valve with an arrow showing the direction of fluid travel.



Now back to the bottom of the case, we center punched the post in the middle of the picture.



We then drilled and tapped a hole for the end of the hose with the one way valve.



After that, all that's left is to install the hose between the new hole you tapped and the stock oil injection hole. Make sure that the arrow on the brass one way valve points toward the water pump. Cut your hose to fit and put it together. This will allow mixed oil to reach the bearing in the water pump shaft.

Finished product.





Some of the shaft bearings are failing and some are not. I think this has a lot to do with when you did your oil delete. When we took this motor apart there was a small amount of oil in between the inner bearings. The oil was there from the stock oil pump. If you do your delete and don't drill the case then you probably won't have an issue for several rides until the oil that the oil pump put in the case is depleted and the bearing runs dry. If you do an oil delete on a new motor that hasn't been run and don't drill the case, without a doubt you will experience issues much sooner than someone doing it on an old motor. Hope this helps. Any other input or theory's are welcome, just please try to keep it somewhat civil.
 
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Nubulin

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Wow,

GREAT POST. This has been explained several times on here, but not like this with pics.

I too have been thinking about ditching the oil injection on my M1000 and now on the M8, but was not sold on the "oil injected bushing" marketing line. As I recall, there was a lot of drama on that subject with BDX "rethinking" it last spring. Drilling the cases is one of the "good" ways to do a delete IMO.

I assume this is more or less the same on the M8?
 
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JHG

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I assume this is more or less the same on the M8?
I would guess they are the same inside due to being the same manufacture but I'm not positive. Once this motor goes back together we'll tear down an 09 M8 the same way. If there's any difference I'll post pics but I suspect they are the same.
 

montanasledder

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Thanks, Greatg write up with pics. I did the same things to mine a few weeks back. Drilled the PTO side case and ran the hose between my new hole and the existing hole the oil pump fed before. The pics made me understand better what i was trying to get premix in


thanks
 

snowmobiler

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i have a cyl off.so i should be able to drill and stop when it hits the crank:)without splitting the cases and clean out any crap that gets in there?
 
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montanasledder

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I kept my drill bit and the tap coated with grease and drilled real slow. the grease held all the shavings and going slow kept me from hitting the crank/rod

real easy
 

Woody67

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we did mine the same way. We did have the cylinder off so we could see what was happening. With the grease technique and careful drilling there was very little if anything to clean up. We did swab with a q-tip for safety. I don't think I would be scared to do it now with the cylinders on. sled was never run with the oil injection and has 800 trouble free miles on it now.
 

snowmobiler

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cool.some bonus tips would be drill & tap size.and case thickness so i could put some tape on the drill bit :)
 

JHG

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cool.some bonus tips would be drill & tap size.and case thickness so i could put some tape on the drill bit :)
Sorry about not putting the drill bit and tap sizes in the first post. I was being lazy and didn't want to walk back out to the garage. Here they are:

Drill bit is a 13/64

Tap is a M6x1.0

Case thickness is about 3/4", its 0.774 on the micrometer.
 

76FOMOCO

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Nice write up, we did this to the old 900 cranks when we dumped the oil injection. the difference was we drilled the top case half at about a 45* to the gear on the water pump. this would let the oil run down into the water pump cavity from the top. there has to be some cross circulation past the bearing or the oil would just build up and the ones with the delete kit would burn down in a few rides. just not enough to sustain the need on one side or the other.
 

m8magicandmystery

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[QUOTE=BigHoe
However, because the oil injected in the case can not escape the cavity to lube the crank bearings, the opposite is true of the premix getting to the water pump shaft QUOTE


GREAT POST WITH PICS...what i can;t understand with the above statement is i kept the stock banjo fitting in the bottom of case and ran a clear line (with top plug)up to where i can fill the water pump drive cavity every few rides by filling the line...the interesting thing is i can put alot of oil in that line if i want and it will just keep seeping down...so its filling that cavity and then some cause the engine will smoke at first if i over do it...so how did the excess oil get in the crankcase to the combustion chamber to smoke if i add excessive oil if your above quote is the fact we are dealing with...???...i just add a few ounces now to prevent that issue of overfilling and i am rest assured that the cavity is filled..but im confused cause you have gone through alot of trouble and great pics and see first hand...but my oil is not leaking anywhere external and it will transfer if i go overboard in filling my line ..!!...???
 
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1100Cat

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Same as m8magicandmystery mine is a 1000 so it happens on 8 and the 10's and the excess oil is getting in somewhere. I have not had case apart to inspect put fill my line with to much oil and she smokes like a mofo so the oil is getting in. I could keep filing with as much oil as I want,nothing stops it so where is the oil going? Any answers how oil is getting into bottom end then if your injecting it into a line to the cavity?
 

JHG

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In this motor there is no way the water pump shaft is getting any lubrication from premix oil. When we pulled it apart there was a black sealant on the crank bearings that pretty much glued them to the case. I can't see anyway other than a very, very slow seeping that the oil could escape from the cavity formed between the crank bearings.

This post is just for general information, everyone decide for themselves if it's necessary to drill the case.
 

bart0678

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The test subject above is my motor. in stock form there is a line running directly from the oil pump to the water pump shaft cavity. This oil line is proportioned in comparison to the oil lines running to the intake boots to only run a small amount of oil to the pump shaft. The crank bearings are oiled via premix in stock form. There is a hole in the upper case half above each of the 4 crank bearings and the bearing cases are drilled to accept oil from the premix of the motor.

By running an oil delete you will still get the same amount of premixed oil to the crank bearings but there is nothing to lube the water pump shaft. This is the reason that Joe and I ran this line from the bottom of the case to the cavity. I will be deleting the oil pump on my m8 this weekend but instead of tearing the motor down to drill the cases (which in my opinion is the only way to ensure a clean job) we will run the one way valve on the stock bolt location with a small hose like some of you have posted. But with the one way valve installed and the cavity prelubed, the oil should last for a while because it cant seep out of case via the line. The one way valve im talking about is in above pictures with the arrow pointing in the direction of flow allowed.
Ill have to watch how much it actually takes but im sure a small amount will go a long way.
will keep you posted
adam
 
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montanasledder

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Bart ive talked with numerous people that have drilled the case when the engines still assembled. The grease trick and drilling slow works. I suppose a very small amound can get into the case.
 
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