MCX 190 turbo install SMOKEING Burning oil

[Father Mike]

Ok im looking for other opinions before i take this all apart again,

2008 Yamaha Nytro rtx.
-Before turbo install i drove the sled all winter 0 issues. The week before turbo install went on a 200 mile ride 0 issue.
-Bought a used MCX 190 turbo from a buddy who parts out sleds. Hes been very helpful and is willing to give me parts from a turbo kit he has for parts.
-I installed turbo kit exactly the way MCX tells you to. i even had a Yamaha tec look over my Install and he told me he sees no issues with the way it was installed.
-Right from first start up the sled would smoke and have milky whiteish oil coming out the exhaust.
-I have oil come from the turbo from the oil return vent line that goes to the air box. I dont think thats normal.
-The oil plenum at the bottom of the turbo is FULL of oil
-The scavenge Pump is pumping and is working. But seems it cant keep up.

when i contacted MCX they told me something is wrong with the oil return thats why turbo is burning oil. they told me could be one or both of these.
-Maybe oil return pump is not working properly
-Maybe banjo bolt on the oil pump is too long

Any wisdom or advice would be very much appreciated. Im very frustrated already and regret even putting this turbo on. I had a perfectly functioning sled before.

I have my buddy thats will to give me parts to help get this going. I original thought that maybe the seals in the turbo were done. So i had got a different turbo from him and was gonna change that out. Thats a big job and would like to think its not the seals.

 

[mbarryracing]

If the bearings / seals were that smoked that they puked oil that bad, it probably wouldn't spin freely because the wheels would be rubbing the inside of the housing, doubt that is the case from your description.
I am not totally familiar with the MCX turbo model they used, but other MCX have been a journal bearing type that needed more oil supply volume than the ball bearing types. You might want to check if that model turbo that is on it requires some sort of oil restrictor in the oil feed line or not. If it's supposed to have one and it's missing it will be over flowing into both the compressor and turbine side housings...
That symptom is exactly what you'd get on a ball bearing type turbo with a missing oil feed line restrictor orifice... or an oil scavenge / oil return line that is not flowing enough to keep up.

If the oil supply is correct, i'd focus on the oil return. None of the turbo models can withstand any back pressure on the oil return side or the oil gets pushed past the shaft seals. That Nytro kit has that mag side flywheel driven oil return scavenge pump. If the drive pin / key way is broken or sheared it won't drive the pump and it won't suck oil from the turbo but the oil pressure from the engine will push oil through the whole system so you will see oil coming out the return hose still, just the whole system is under pressure. Tell tale sign might be that plenum / catch tray being full under the turbo...

However, you mentioned another real clue, the vent line to the air box is pushing oil? Make sure you don't have the oil return line and the vent line from the turbo switched... If switched the oil return scavenge pump is sucking on the vent instead of the bottom of the oil catch tray on the bottom of the turbo. If correct and the oil is coming out the vent line then it's another clue that the oil return is backing up and not scavenging, overflowing into the vent.

Also a tip. Highly likely your exhaust and your charge tubes / air box are full of oil and will need to be cleaned out.

 

[ClutchMaster]

You should remove the scavenging pump and test for proper oil flow, they do go bad. Make sure there are no restrictions in either of the lines going to and from the pump. I’m not sure if MCX uses a restrictor in the oil feed line, if they do that could be missing, someone here should be able to chime in.

 

[kinger]

Can't say it better then @mbarryracing Validate the restrictor, then validate the return pump is pumping oil. I would think you could un-hook it from the engine and dump the hose in a cup and fire it up, see how much oil comes out of the hose. I had the same issue on my gravity fed return line Impulse turbo kit and the line needed to be bigger.

Don't give up, this is a small kink, they can be reliable when done.