crankcase vent mesh screen

[93Bandit]

I don't mean to distract from the topic at hand, but if this mesh is missing can it cause excessive oil consumption? I've got a fair bit of oil in my airbox and I assume it's coming from the vent

[CincinnatiKid]

That is actually the basis of this conversation… welcome, read the above posts.

short answer, it certainly could be your reason, there’s one way to find out for sure… replace it!

[93Bandit]

That is actually the basis of this conversation… welcome, read the above posts.

short answer, it certainly could be your reason, there’s one way to find out for sure… replace it!

I read the thread, although I must admit I only skimmed it. However, it seems your main concern is oil draining out of the airbox, rather than oil consumption. Maybe they go hand in hand? I burned a half quart in 430 miles which seems excessive. I don't have any oil leaks and don't notice any blue smoke, so I'm not sure where it's going. I think the mesh is still in the cam cover but I don't remember for certain.

[CincinnatiKid]

I have no airbox , using pod filters. My breather hose terminates into a small catch container. That catch container was overflowing and dumping oil on my rear tire and brake.

If you’re missing a half quart into your airbox after 400 miles, I suspect you’d notice it leaking out of the airbox somewhere, maybe???

1) do a leakdown or at least a compression test to make sure your rings are sealing tight, rule out oil burning in the combustion chamber

2) maybe pull the breather from the airbox and route it into a makeshift catch can that you can inspect after 100 miles or so.

are you doing a lot of 80+ mph riding in those 400miles? My reading on this site is mostly people who are losing crankcase oil through the breather while doing extended high speed miles on the interstate.

[CincinnatiKid]

Got some mesh, and packed it above and below the gasket. Figured there’s no such thing as too much.

[CincinnatiKid]

Increased catch can capacity by 1000% and added a breather hose with filter to the catch can. And in the spirit of “why not?” I rolled up some wire mesh and stuck it in the catch can.

[joequesmith]

Friends old race bike. Note how the hose runs to the top of the bottle with paper towel at the bottom. Several holes at the top act as the vent.

Looking at the photo of your bike at the track, they allow you to run without a chain guard? We have to have a guard and catch can. Diaper wasn't required, but I run them on my bikes.

can3.jpg

[CincinnatiKid]

I know that many track day orgs want a chain guard, it’s never been explicitly required on any of the days I’ve gone, and no tech inspector has mentioned it. But most of them are used to inspecting modern bikes…

probably ought to source one and keep it handy though.

thanks for the pic

[93Bandit]

I have no airbox , using pod filters. My breather hose terminates into a small catch container. That catch container was overflowing and dumping oil on my rear tire and brake.

If you’re missing a half quart into your airbox after 400 miles, I suspect you’d notice it leaking out of the airbox somewhere, maybe??? You'd think so, but the rubber drain hose is missing from my airbox so it's just got that large hole in the bottom. I haven't noticed any oil leaking out the bottom, but I haven't paid much attention to that area. I also don't keep my bike as clean as I should and frequent dirt roads so the dust might be soaking it up, maybe? I only recently noticed the oil in the airbox.

1) do a leakdown or at least a compression test to make sure your rings are sealing tight, rule out oil burning in the combustion chamber I did a compression test a few thousand miles ago and it was at the high end of the spec. I'd be surprised if anything has changed since then, it's running very well.

2) maybe pull the breather from the airbox and route it into a makeshift catch can that you can inspect after 100 miles or so. Good idea, I'll have to try that.

are you doing a lot of 80+ mph riding in those 400miles? My reading on this site is mostly people who are losing crankcase oil through the breather while doing extended high speed miles on the interstate. Yes, actually. I've been commuting on my bike the last ~1k miles which is about 70 miles round trip @ 80mph. Sometimes I take back roads which is slower. Maybe I'll experiment, 500 miles on interstate only, 500 miles on backroads and see how they compare.

Answers in red.