how much oil in crank case is normal?

[JuliusCaesar]

so, the more i dig into this 1993 xp project the more i'm thinking i know why it wasn't starting for the original owner this spring. I'm thinking it was hydro locked with oil. When i bought it i tried turning the PTO over by hand and it wasn't budging. When i got it home and pulled the engine and rotary valve cover i was able to rock the PTO back and forth to finally get the valve to rotate but in doing that, oil was pouring out of the rotary holes in every rotation. Reading that the only place there really should be a lot more oil is in the rotary shaft chamber and not the crank rods. The crank rods and outer bearings should be in oil, but no where near the amount that was leaking out the holes when turning PTO over. Now i'm reading it more than likely is the inner crank seals. Meh, not overly happy about getting a crank rebuilt on a 30 year old ski and when turning over the crank it sounds just fine.

Personally if i can just put a shut off valve on the RVC line and call it a day i will, but please confirm that the oil in the crank case should just be enough that the bearings and rotary valve shaft are lubricated.

 

[mikidymac]

There should only be a very tiny amount of oil if it has been sitting. Nothing should be "submerged" in the crankcase area where the rods are.

 

[etemplet]

so, the more i dig into this 1993 xp project the more i'm thinking i know why it wasn't starting for the original owner this spring. I'm thinking it was hydro locked with oil. When i bought it i tried turning the PTO over by hand and it wasn't budging. When i got it home and pulled the engine and rotary valve cover i was able to rock the PTO back and forth to finally get the valve to rotate but in doing that, oil was pouring out of the rotary holes in every rotation. Reading that the only place there really should be a lot more oil is in the rotary shaft chamber and not the crank rods. The crank rods and outer bearings should be in oil, but no where near the amount that was leaking out the holes when turning PTO over. Now i'm reading it more than likely is the inner crank seals. Meh, not overly happy about getting a crank rebuilt on a 30 year old ski and when turning over the crank it sounds just fine.

Personally if i can just put a shut off valve on the RVC line and call it a day i will, but please confirm that the oil in the crank case should just be enough that the bearings and rotary valve shaft are lubricated.

Zero oil in the crank case. Oil injection and fuel provides lubrication. Intall a butterfly valve on the line to the Rotary valve chamber. Shut it off when not riding. Not all leaks are equal. You might be able to leave the valve open for a week or several weeks with no issues. You'll have to determine that. I use these 3/8" INSIDE diameter going on 4 years on my wife's ski, no issues.

 

[JuliusCaesar]

thx and as i suspected. When i work on sleds and getting cranks sent off to my guy for rebuild, there is MINIMAL amount of oil in the crank. The check valves just spit out enough to keep the bearings lubed. That's why i thought it was somewhat odd that every time i spun the crank around, oil was leaking out of the holes on every other rotation.

I don't know what 2 stroke oil he was using, it looks brown / red from what i can tell coming out of the case. I'd like to change it all out to Lucas AP semi synthetic. Can i just pull the drain plugs at the case bottom and drain the remaining oil out of the crank case? will it need to be flushed out with gas? Not sure how well these oil mix. I know for my sleds, i can wait till the oil tank gets down far enough that we can just add another brand without issues. Or at least i never had an issue in 20 years.

 

[etemplet]

I have the same attitude as you do about oils and that is backed up by knowledge and experience.
I would put any gas in there as it will thin the oilI also wouldn't remove the fittings they are a pain. if anything pour in some new oil and let it run out the other side (at a low point) that way you'll flush with good stuff. I think you'll be fine.

I contemplated putting a heavier oil in my wifes ski due to the leak but I wasn't necessary. It is something to consider. Perhaps a light mix of 75w with the injection oil. I don't know how much it circulates but I don't think much at all. LOL I absolutely will NOT tear down a good running engine. Good Luck !!

 

[JuliusCaesar]

Got it, will do just that. i'll drain what i can and just add the Lucas and do a few pour and dumps to get most of it out and burn whatever else is in there off. Engine otherwise looks good. PO had thought it was the rotary shaft at first and replaced it (without splitting case) to only have the same "seized" feeling happen and i guess he dumped it off to me for $300. Everything else looks to be in good shape. Cylinders and pistons look great. Piston crowns a bit richer than i like, but we'll see how it runs first. Bought it not running so crossing fingers it works.