449/511 Engine Breather for the DIY Guys

Like most guys on here, I've had the occasional bout of oil in my air filter from the engine breather and it has happened to me the last few times I've ridden.

I also want to acknowledge right here from the start, that there is an easy, well made & well priced fix for this available from one of the CH site sponsors in the Zip-ty breather.

However, I've been looking at my engine recently & wanted to see if there was something I could do myself. This is what I came up with.
I've been out today with 2 of my good riding mates today & we did some of our more advanced stuff, dropped the bike a couple of times, ran out of talent on steep hills, revved it hard on the long straights & very happy to say there is not a drop of oil in the air-filter at days end. Sweet.

I noticed this plug in the RH side of the head between the 2 cam-cover half-moons and had the thought, if I tapped a thread into the hole & fitted an elbow, the engine could breathe up past the cam-chain & on up to the air-cleaner as it should.


This is how I went about it.




First, pull the head cover.



Next, place a finger full of grease in the hole behind the plug to catch any drillings.

Carefully drill a hole through the center of the plug to suit a thread tap, mine was a 6mm tap as I had a long 6mm bolt to suit. Tap the thread all the way through.
** Be especially careful NOT to let any fillings get past your grease into the engine**



Choose a bolt with a little length in it & use it to 'jack' the plug out. (It is just glued in place with Loctite).
I used my long bolt, a socket that cleared the plug & a washer.



I purchased a 1/4 BSP thread 90deg elbow with a barbed end to suit 1/2 hose from a local auto parts store. I already had a 1/4 BSP thread tap which was a good fit for the hole without drilling.

Again, use grease to catch any shavings & be careful not to jack the tap into the inlet cam sprocket which is close to the back of the hole.
Put some sealer on the thread & screw in the fitting.
I was able to fit the factory breather hose, uncut, to the fitting & had a slight rise in the hose all the way to the air-cleaner.




While a the parts store, I got a 1/2 emission rated sealing plug & fitted it to the factory transmission breather to block it off.

Total time was about 2 hrs all up & running again.

That is a bad spot for a breather as the cam chain slings oil heavily and then the breather gasses will push more oil into the line. Not the best way to do it. Also if you snag something it will crack the head most likely. I would rather replace a valve cover than a cyl head.

I appreciate the ingenuity but when there is a tried and true method avail, for cheap that is a better way to do it....I am all for saving pennies and doing it yourself but man that looks like a headache to me (literally).

Good on ya for your further experimentation Dangermouse! Me, though, I'd be quite a bit more hesitant drilling into my cylinder head vs. paying $40 for the ZipTy version that uses the valve cover. I realize you mentioned this at the beginning of the thread, so I guess I am in full agreement with your statement "I also want to acknowledge right here from the start, that there is an easy, well made & well priced fix for this available from one of the CH site sponsors in the Zip-ty breather."

As a mechanic, I understand the risk & weighed that against what I know.
If you live in the States, the Zipty breather is too easy.

Husky, I expected to see some oil carried around by the cam sprocket & out the new breather too.
In practice, it doesn't do this.
My guess is the oil clings to the chain & passes by, rather than being flung with the sprocket. There's no high pressure oil near the chain like there is in the tappet cover area.

It's working great.

With regard to the fitting or head getting damaged, I think it is fairly low risk, the fitting is brass, so should crack at the threads before the head let's go & it's tucked in behind the radiator, exhaust & my leg.
Also, I didn't do it for the cost, more an experiment too see if it worked. Easily reversible by screwing in a blank plug so I had nothing to loose.


Thanks for the replies.

Congratulations, you now have a hole in the side of your $1500 Husky head.

Lmao.

I would think there would be lots of oil coming up from the chain.


Did you cap the crank vent or are you running both?

Nice pick-up, but I always had a hole in my $1500 head.... it had a plug glued in there.
If I want to change it back I have a threaded plug.

No I capped the trans fitting.
As mentioned, a full days hard riding had no oil in the filter.

Lol.

Mmmmm, very professional Tink, nice!

Ran the engine & shot a video of the breather with no hose attached.
No oil slinging problem there, all good.

David , good Job.....

fuk the haters .... it will work.

Not a hater, just providing criticism.

Congratulations David,

You now also have an extra $50.00+ bucks in your pocket. Which is one of the many benefits of doing it yourself and you now have a permanent fix that works. I use "the valve cover fitting" myself and I made my own tank on my G450X that works great. This type breather set up is something that has been done on bikes and carts for years though.

By doing what you have done though. You also don't have to fumble with O-rings, spacer sleeves, longer bolts and drilling your valve cover out with a Unibit that has proven more than once to drill an offset hole in that valve cover to install that fitting.

By the way, these pictures of these messed up holes in those valve covers have been posted on here. No solution has ever been offered on how to fix them other than go buy a new one. Which was a decision that had to be made by those who unfortunately posted the pictures of what that Unibit did to their valve cover probably as well, when they used an electric or air hand drill.

I have a milling machine in my shop and use it like a drill press quite often to do stuff like that, instead of using a hand drill. For some a hand drill can do more harm than good in the wrong hands. I know, My dad was a shop teacher for over 40 years in Oakland CA. Not all people took shop classes though.. Just about the first thing they teach in shop is how fast or hard you can plunge a drill bit through a given piece of material. Some learn that lesson, some do not.

Look, what I am trying to say here is. Thanks for pointing out that there will always be "The Haters". Its a fact, that if you don't always follow the Pied Piper. (I'm one of those people myself). You can also get a kick out of the enjoyment of listening to the consistent typical associated condescending remarks. Or those of the followers. Which are also consistent with every associated condescending remark. They all seem to follow nearly in consecutive order after every DIY 449/511 post. They all are more than 50 bucks short in their pocket. LOL !! All the DIY 449/511 posts are great for saying hello to all of them in consecutive order as well. Hello.

So David, Just sit back and laugh with your well deserved, self imposed smile of satisfaction and prestige of knowing you did something that solved an issue by yourself. Consider yourself lucky, There seems to be only a few of us. Its pretty clear, some people can't think for themselves. That's obvious.

Even though they still have shop classes in the school systems, this kind of stuff isn't easily taught to people who are brought up to think they already know it all or just pay to have everything done for them.

That smile of prestige of yours, itself is worth more than the extra 50 bucks in your pocket.

In fact it's priceless.

Lets here it for the DIY solution.

Along with that will be all the remarks from everybody who thinks differently than yourself. If they think at all, probably in typical consecutive order.

Love the ingenuity dangermouse! Yours and the many other solutions to common problems makes being a member of this forum priceless!

Can you explain the mechanics behind your solution to the oil not ending up in the air filter?

Well, it's a little hard to know for sure as the lid is on when running, but it is the chain that carries any oil that gets to the top sprockets. My best guess is the chain stays wet but isn't dripping in oil. Anything that does fly off goes to the head cover.
However it happens, I pulled the hose off and leaned the bike way down to the right yesterday, engine idling, no oil came out at all.
Then I revved it up with some paper towel near the outlet & it stayed dry.

A few of the comments above mentioned saving money. That is NOT why I did it.
I'm a mechanic, I love to tinker & fix things, its my own bike , I like to do things my way & if I find something that will interest people like me I WILL post it up.
If this isn't you, please go aheah & buy made parts & fit them (I took the time to point that out 2nd line of the post) If not, move on!!

How much oil are you running in your engine and what spec oil are you using? (By the way congrats on the wallabies beating the pumas earlier)