So I have to ask a question here - Is this blow by noticeable without removing the air cleaner cover? I suppose I can answer my own question by taking the cover off and looking to see if its a problem (currently traveling on business), but was just curious to know if I'm not seeing it external to the cover, if I can stop worrying about it.

 

 

Nothing wrong with installing a catch can. But understand that this sludge accumulating in your catch can in most cases enters the cylinders at such a slow rate that it burns away before accumulating. The ideal application for catch cans is on direct injected engines whose intake valves never see a fuel wash from the port injectors and this oily sludge cokes up on the back side of the intake valves and cakes the downstream side of the throttle body over time. Of course excessive vented residue that some are reporting over reasonably short mileage can be an issue even with port injection. So yea, nothing wrong with a catch can.

 

Have always kept oil level at half way point on dipstick. The only oil I am having to add is an couple of oz here and there. Which makes sense as its ending up in the throttle body or the air filter.

 

I think that depends on which air cleaner you have. If you have a 107 with the stock air box it might not drip out. But I would remove the cover and inspect the air filter. I have the Ventilar air cleaner which is an open type. Its easier for it to drip out. I haven't so much dripping as the filter element getting saturated. On mine its easy to see. Just look at the bottom of the filter.

 

The interesting part is its a problem that makes itself worse. When the air filter gets oil logged it becomes easier for the motor to suck air in through the breathers than it is to pull air through a dirty filter. In turn more crap gets sucked in. Easiest fix is a catch can. My evo actually does this sometimes even after I put new umbrella valves in.

I really think the sumping issue is a combination of things just like this. With a poor breather system it cant be good for crankcase pressure. It has to be a few things being off to cause the sump issue, it even explains why some bikes have it and some dont.

 

2018 RGU 7300 miles.

I recently cleaned my filter, using the book method of soapy water. The filter was removed after 7k miles. There was a fair amount of oil soaked into the bottom of the filter, directly below the breather hose, but nothing I could detect above. There was a dollop of oil sitting right on the bottom of the intake throat of the throttle body.

I'm thinking this oil on the throttle body, as well as the filter area below it, is dripping out of the hose during times the bike is shut down overnight in the garage. Couldn't be more than a drop here and there, but builds up over time.

Nothing much gets out of the filter element. The inside of the air box is all but dry of oil. My engine oil consumption is what I consider normal, a rate of about a quart every 5k miles.

 

Agree on all points. As you say, the more oil soaked the filter gets the worse the problem. And once the filter gets so oil soaked you cannot clean it enough to make a difference.

 

[QUOTE=Yamaharley;17597413]The interesting part is its a problem that makes itself worse. When the air filter gets oil logged it becomes easier for the motor to suck air in through the breathers than it is to pull air through a dirty filter. In turn more crap gets sucked in. Easiest fix is a catch can. My evo actually does this sometimes even after I put new umbrella valves

These are one way valves, you are going to have to explain how they can suck in.

 

I have new stock breathers on the shelf. They are not exactly one-way, they do leak a bit.