449/511 Breather hose mod

I run a 1000cc every oil change. I think the key is figuring out what oil stays most stable in our bikes so our airboxes don't get the drips. My first oil change had fuel mixed in with it probable due to ring blow by from the rings not being seated well. Now days I just put a valve stem cap on the drain and turned the airbox into a catch can. surprisingly little oil traps in there now, haven't had a drop of oil on the red paint in a while either .

There is actually room on both sides of the cylinder. I was originally placing the unit on the left hand side, there is a lot more room there, but placing the drain back was an issue. Although now, I think I will be capping off the original breather and creating a new one in the valve cover. The drain back can be fished around back to the filler without a problem.

When the bike sits on its side stand the oil will drip out the left side of the airbox (noting the airbox drain is on the rigut side making it higher and thus wholely useless as a drain) and eventually make its way down the backside of the radiator. There it will collect dust and dirt and block airflow through the rad which causes rapid overheating. So yes, this is a serious issue.

The other day I made the mistake of thinking the oil level was a bit low so I topped it up with about 100 mls. The motor subsequently pumped the excess into the airbox which I am finding highly annoying now.

I wouldn't ! The engine is a dry sump design and there might be quite a bit of oil and pressure underneath the valve cover, probably lots of oil mist with all those high speed thingies spinning .

The original purpose of the air box drain is to drain in case of water collection. My drain is currently capped off, but I will be adding a 3/8” diameter hose and direct it down under my skid plate. The oil in the air box is quite annoying, yes, even more so when it drips down on our engines. Running a hose down to the skid plate will fix that issue, but you will need to check your oil levels periodically since you will be depositing oil on the ground. Once I finish my oil reclamation project, oil will be returned automatically. Venting the left over gas to the air box is still the best option, especially for track racers.

The oil sump is not dry like an XR oil sump in the frame, but I like to think of it as kind of a hybrid sump where the oil is kept in two separate containers both in the center rear of the engine and the right rear hand side of the engine. The good thing about this is that over filling the case does not impede the rotation of the crankshaft, it gets its oil solely from oil flow.

The breather gas entry point and the timing chain space are both on the same side of the engine, away from the crank so blow by has to make its way around to the outer case. Oil is spinning around and spraying out of all kinds of places in our cases. There is a huge advantage in collecting gas from the valve cover as opposed to collecting it from the stock breather. Since the breather obtains its gases from those that flow past the torque limiter and not from the top of the case, oil sump levels must be quite low in order to keep from pumping liquid oil up the breather. I agree with you that there is quite a bit of oil spray from under the valve cover and obvious baffling would be necessary at the entry point. The clear advantage to retrieving crankcase gasses from the valve cover is that it frees up the ability to store more oil in the crankcase. At this point, the valve cover breather hole is not in my design parameters, but I am looking into it.

At some point we have to look at the bigger picture and ask is all of this even worth the trouble? So I am curious, what is the point at which it becomes viable? Is an increase of 20% in oil capacity worth it? 20, 25, 30 35%? If we look at our oil from a cooling and not just a lubricating capacity, increasing our levels becomes more appealing.

incredibly tired of oil everywhere and the bike leaving puddles on the grpund after a hot ride. have been putting 1000cc in every 500 miles and I couldnt get it to stop spotting like a harley.catch
can
was my solution.

Nice! That looks very similar to the prototype tank we tested.
Does your catch return the oil or do you just drain it at intervals?

its not set up to recycle the oil. just drain it. havnt figured out how long I have before I have to drain it since I just installed it last week.

I have never removed the throttle body, piston to see the affects of the oil spray on the Internal workings. I would think the oil buildup inside the Air Cleaner would require frequent throttle body cleaning. What is the Carbon buildup on the piston look like burning that oil? Thoughts? Great Thread and Really good input. However, I am still up in the air about how to solve this problem.

It looks awesome and definitely a step in the right direction. Take a look at some of the diagrams I posted on husky's returns. Many systems just return back to the drain plug. Drilling and tapping the case is another option.

Not sure what the build up is like from raw oil, can't be good for the plugs. The breather bottle is designed to not only catch the oil, but condense it before it makes its way back to the air box. Alternatively you can put a separate air filter on the breather like the one hedz0r has. I prefer having a closed system that I don't have to maintain and I like putting the vapor back to the air filter and not out to the open air.

Time to fire up the old tig welder. Still has to be acid washed and prepped. I should get to it mid week if all goes well.

Just a quick update from my SMR449 being hammered (as in; raced...some may call my speed putting around other may say flauging it) over the weekend in 35C heat - no oil problems (Don't have any return oil apparatus!), no electrical problems (Done the earth mod - moved it to the back of the motor and moved the condensator away from the motor to the side of the frame, std. spark plug) Only thing over heating was me but ice and wet towels helped cure that!
I have the 2012 airbox, JD Tune(cant remember the settings) and an Arrow slip-on!

Maybe you need a cooling vest? 95 degrees is pretty hot, I rode in 106 degree weather and it was too hot for me, especially in the technicals where I didn't have enough air over me. Glad you had a good race, no issues. The oil breather mod isn't for everyone, it does allow higher levels of oil without the annoying mess.

Quick update - I was able to sit down @ Zip-ty and weld up most of the breather yesterday(I haven't welded aluminum in 10 years, kinda rusty lol), I will have to add the mounts later this week hopefully.

Getting back to the oil level discussion, krieg found the 2012 workshop manuals for all of the bikes here: http://www.husqvarnafactory.nl/pdf/2012.htm

He posted it last night. Big thank you for that.

I looked at the workshop manual and the oil level has been revised. It shows the min mark at the bottom of the sight glass and the max mark in the middle of the sight glass. The 2012 user manual I received on the flash drive shows the min mark in the middle of the sight glass and the max mark at the top of the sight glass. Maybe Husqvarna is reading this forum!

The 449 engine was originally created by BMW for use in the G450x. The engine was designed to operate with 1150cc of 5w40. Riders now are using as little as 800cc of oil in order to combat the oil blow-by issue.

While I was building this, I kept coming up with new and better ways to make a new one. Hopefully this prototype will test well. So far I am running 1336cc (1.41 quarts) of oil, no blow by. That's a 67% increase over running without a breather.

very nicely done.