[michaelwhays]

Just got my bike back from vince last week after some gearbox work (see earlier thread) and some upgrades (electronic ignition, turn signals). Went for a ride around seattle this evening after work. i really didnt know where i was going but at one point i decided to turn around. so i pulled across the lane and into a driveway. I though i was pulling out the driveway when i reentered traffic but it turns out that i was a few feet passed the driveway. i sped over the curb.  A pretty big bump but the bike seemed to handle it well. i was impressed. i continued on and got on the highway up to about 55 mph max. after i exited i found myself in a cloud of smoke. oh crap, what did i break this time?! i looked down and saw oil dripping from the air-box and sizzling on my nice polished exhaust. i pulled off and cleaned up the mess the best i could. the dripping seemed to stop. i drove the rest of the way home and when i shut it down i heard a pissing sound. sure enough a nice stream of hot oil from the air-box. so whats going on? i pulled the air-box off and dismantled it to clean it. the air-filter is soaked in oil and there seems to be a bit of residue in the carb.
My theory right now is that when i took the big bump off the curb while accelerating, some oil in the crankcase sloshed into the breather and coughed out into the air-box. perhaps the high speed caused enough pressure to make to oil blow worse. does this seem reasonable? Any ideas? i think i should probably drain the breather tube and catch can. Also i think im going to have to replace the air filter as it seems pretty saturated. I noticed that vince replaced the tube that connects the air-box to the catch can with a nice quality straight fitting that doesn't kink like the old one. 1300 mile 06 500 classic.

[Coronach]

This is God's way of telling you that the Bullet needs a duckbill, not a catchcan.

Mike

[michaelwhays]

I have thought of this mod. What is the advantage of having a catch can over a breather, and if there isn't one than why did they take the trouble to add it? why is it necessary to recycle the air from the catch can? are we that short on air? seems like two systems you would want to keep separate. airfilter and oil. now i have an oil soaked airfilter. What i want to know is if this is going to keep happening or if it was just one spert of oil and i jsut need to clean it out of the system. if i had the duckbill system i may have not noticed it. and i sure would want to dump all of my oil in one ride and not know it. (i hope that wouldn't happen) not that is in any way a good reason to the design. i would prefer to learn some other way than flooding the air-box with oil..

[Bath Bullet]

Been seeing a few mentions of this on here of late, could I just dis-connect the plastic pipe from the catch can and set it to drip over the chain?
whats this duck bill, where do I get one if needed etc?
Thanks
Terry

[Bath Bullet]

Thanks Phil.

[The Garbone]

I thought that was a duckbill in the bottom of the catch can?   I reused that when I removed mine.

[PhilJ]

It is a duckbill. I just wanted to keep the can intact in case I ever had to reuse it for emission testing, should it come my way. 

[Rick Sperko]

If there was enough oil to fill the catch can, flow into the air cleaner, then piss on the floor wouldn't it be dangerous to run a duckbill to the chain? Seems like some would get under the rear tire. Running it behind the bike would have been a danger for anyone behind him.

This is coming from someone who has read a lot of posts on this, but never seen it done. I want to remove my catch can, but this is my concern. I hope I am wrong.

-Rick

[Coronach]

The chain oiler aspect, I think, is probably not the reason to do the mod. Apparently, the type of oil discharged onto the chain is not the best type of lube for the chain, it is not discharged in the type of volume needed toactually do anything substantial except attract dirt and grit. I've read that routing it aft and having it drop behind the wheel is probably the best way to go. As to it being a danger to other motorcycles, again, we're talking a small volume of oil, here. Probably not enough to make any difference whatsoever, but I could be wrong.

As to why the catchcan system was added in the first place, emissions controls. direct venting of crankcase vapors to the atmosphere is, apparently, a huge sin.

Again, this is based upon my reading.

Mike

[Slider]

A duckbill is a one way valve, allowing a pulse of air to escape the crankcase/oil reservoir as the piston come down. You want it sucking air in like it would without the valve.

Wait a minnit, now I'm confused (sorry, it's in my job description). If the duckbill is a one-way valve, allowing spurts of oil/air to escape, how can it also suck air back in? Or am I just reading that wrong?

[michaelwhays]

So should i be concerned about a deeper problem for this much oil loss through the air-box? I'm not to sure how big of a deal to make of this. i would hate to buy a new oil filter, hit the road and have the exact same thing to happen again.

[michaelwhays]

Ill give you a ring Vince and get your opinion.

[Bath Bullet]

It is a duckbill. I just wanted to keep the can intact in case I ever had to reuse it for emission testing, should it come my way. 

Going off topic very slightly, this is why I carefully preserved my PAV parts, I can easily get another drilled manifold as I have tap & screwed mine, but that PAV pipe and valve costs £116 to replace!
I cant really see the point in taking that oil catcher off, if I keep an eye on the level and empty it It should not foul up the air filter.

[Vince]

     Michael, your theory may be correct. I don't know because I haven't  inspected the bike for this. Problems like this are some times due to excessive crank case pressure. It can be from a blocked vent or an over fill or a seizure. A long ride at high RPM or High load will also cause this.  If it happens on a regular basis we should diagnose the issue. If it is a one time affair, don't worry about it. But of course check your oil regularly.
    The can is there to recycle vapors. Some people like the duck bill. I don't think I would route the hose to the end of the fender. That long a line can cause excess pressure. It's like an exhaust. You are dealing with flow. For proper flow you need the right amount of restriction.
     Call me to discuss this further.

[michaelwhays]

Just pulled out the plug to check for any sign of oil per Vince's recommendation. all looks good. what does this tell me? that theress not piston blowback through the rings?