How-To: Crank Case Breather Mod (with pics)

[chevnut55]

i used a blue hair spray bottle that i drilled and tapped but it looks like a expencive special part.

 

[Foximus]

Here is my 2 cents...


This is a dumb mod. I mean the idea of it is alright, but the actual implementation of it isn't a plus.

You want your crank case to be in vacuum, not to be able to breath. If your able to keep your crankcase in very high vacuum, at times you are able to gain a decent amount of power.

Really you should be buying a proper catch can and routing a venturi somewhere where there is high air velocity... some restriction point in your actual air pathway.

And remember, for the few of you about to say, but hot air doesnt make power... your not pulling hot air. Your pulling vacuum. Which can't be hot, as there is nothing to transfer the energy up the tube.

 

[Petrus]

Did the mod a couple of days ago. I happy with the results, more so as I discovered that the original breather hoses were installed in the wrong way. The were bend backwards, not allowing the crankcase to breath in a proper way. Now the hoses are straightend and connected with a t-piece and a hose downwards,
Did not install a filter because the hose is long enough and will not suck anything back the whole lenght.
The bike starts more easely and I is not hesitating anymore when cold. Also I had a small hesitation around 3000rpm witch is completely gone now.
Now for the inner airbox mod

 

[pamver]

why use a catsh can if you can dump it strait on the streets and have the same effect???

 

[Baal]

Cause some of it is going to end up on the bike and you'll have to clean it off. Don't know that I want oily water going anywhere in the vicinity of my back tire either.

 

[Stevenc150]

^That's^ why I ran mine down behind the rearset and zip tied under the footpeg. Fit inside the peg like a glove and crap blows past the bike but for a few drops on the swingarm at higher speeds.

 

[Petrus]

@nkaperry

"Remove the breather re-route and re-set the TPS would be the first suggestions. We have seen real issues with breather re-routes and are working to understand why."

This was actualy said by Eric Buell?? and what serious issues is he refering to?[confused]

 

[nkaperry]

@ Petrus

I wrote to Erik on Facebook as a last ditch effort to get ANY information about a running condition I was having. You can see my issue on this thread: HERE
Erik simply said, it would be difficult to diagnose such a potentially complex issue via email but he suggested to remove the re-route and get a tps reset. I just messaged him again for more specifics on the issues they have seen. But it def. is something to think about!

I have yet to remove the re-route and get a tps reset. I haven't been riding at all. But I will keep everyone up to date.

 

[Baal]

In my completely armchair opinion, I'd do the TPS reset first. That's software, and doesn't involve taking the reroute apart. if it still runs poorly, then de-route.

 

[bobaganoosh]

thats definitly nothing to do with the re route. in my opinion

 

[nkaperry]

@ bobaganoosh

While I agree, this information is coming from the man himself, Mr. Buell

 

[bobaganoosh]

lol yea that is true u cant question him

 

[nkaperry]

but i did ask him to go into further detail about the "serious issues they have seen with breather re-routes" and I am eager to do a tps reset both with and without the re-route to see the results. I just have to get the bike to another shop because my local one just closed down and of course being a college student, money is an issue.

 

[bobaganoosh]

i would get an ecmspy cable and u can do it your self. i know the harley dealer around here charges 50 bucks for a tps reset. i got the cable for 40 and i can do a bunch of other stuff with it too. or just find somebody on here with one that lives near u. i'm in southeastern nc if your anywhere near that area

 

[Petrus]

mmm I wonder... the thing is that everybody, including me, seem to have a better running bike. I leave my reroute in place for now untill the opposite is proven and that it will damage the engine one way or another.
Although I cannot imagene why it would. I had on my previous bikes a reroute installed by the factory and had never ever big problems with these bikes.

Ps..I'm not doubting The Man and his wisdom[up]

 

[pamver]

is it a good idear to bring the air filter back to the air box like this?

 

[Pockets]

+1 for cool factor Pamver! That looks great under the blue box. Don't see why that would be any problem. As long as you have the drain line elsewhere, I'd keep that location for the filter!

 

[Stevenc150]

But the suction of the main air flow might pull the "crappage" up in through the small filter instead of draining out as it should. Not sure why you would do it the pictured route except for looks.

 

[Riderdie]

Like Steven said u may get a bunch of crap on that clean looking heat shield. I've got a lot of dirty oil on my primary where my airfiter is located right behind the oil cooler. My filter and catch can are on each end of a t. Thinking about it now I need to go back and put the filter after the can.

 

[pamver]

i whas thinking to do it like this: