mod question

[spazz8448]

ok so i did the How-To: Crank Case Breather Mod just now. i took it out for like a 7 mile ride. in the first mile it was chokeing up and poping like it always did "which is what i was trying to fix" after it warmed up it was running fine. i pull up in the drive way look at the filter and i notice its smokeing....its not hot though is mine the only one that does this? and is there any harm that can come from this mod.

and its not heavy smoke coming out its more like a steam that smells like fuel.

and will it still benifet me to do a airbox mod?

i posted on that thread but im really concerned about it and no one replied :/

 

[snrusnak]

Hey I've noticed mine "steaming" before. I think it's because the oil vapor gets on the filter then steams off. Maybe it's cooling rapidly causing steaming? Maybe the steam/smoke is actually from the crankcase(doubt that). Is you breather filter positioned in a way that oil can run onto it? It should be positioned so it is above the hose, so oil doesn't run onto it, if that makes sense. I don't really think it will hurt anything though.

 

[Stevenc150]

...more like a steam that smells like fuel.

Sounds normal. Are you using a catchcan?

will it still benifet me to do a airbox mod?

The breather reroute was simply cleaning up your intake air & keeping box clean - Not a performance mod. The Airbox mod is definitely a performance mod, especially when coupled with an exhaust mod & custom remapping of the ECM. 2 different things.

 

[vroom]

That is fuel(burnt or otherwise) that has made it's way past the piston rings. I for one am leaving mine alone. With it in the airbox, it'll suck that out of the crankcase. I'm skeptical that such a small amount of that could affect the way the bike runs in any noticeable way. Your oil should stay cleaner with that being sucked out of the crankcase. If it's spitting out so much crud that the bike runs like ****(and you can verify this), then your rings are probably shot or there is something else going on, causing pressure build up in the crankcase.
The way you have it, it could act as a road draft tube as long as the end is exposed where the air is moving past it. It'll stop working when you aren't moving. I don't think it will hurt anything though.

 

[snrusnak]

A couple thoughts:

IMO it doesn't matter that there's no suction on the hose as there would be in the intake because the crankcase will be under pressure and still release the excess pressure out the hose. Have I done some tests? No, but I don't think this is an issue.

The steaming - I hadn't thought about it being fuel, that makes a lot of sense...

Over filling the oil can cause excessive "gunk" from the breather tubes.

I noticed my breather tubes were spitting hot drops of oil directly onto the IAT sensor. I believe this was causing the sensor to read too hot and leaning the mapping. If the engine is at 400 degrees F so is the oil, and if the hot oil gets onto the IAT sensor it will screw up the reading. This, IMO, was a big problem with my bike. I noticed a big difference by just blocking the IAT from oil splatter from the breather tubes.

Lastly, although there is hardly a performance gain and this mod should not be thought of as a performance mod, there is technically a slight performance gain. For one, oil in the A/F mixture lowers octane rating. Secondly, you only get so much volume of mixture into the combustion chamber, if you remove the little volume of oil vapor that there may be then it gets replaced with air and fuel, which equals more power. Even though it's probably next to nothing and negligible, it's there.

 

[spazz8448]

here is how its ran. after the filter it goes up to the "T" then the 2 lines go to where the old one were. i have a plastic catch can as you can see at the bottem.

 

[snrusnak]

Yeah doesn't seem like the oil would hit the filter with the way you ran it. I don't think you have to worry about it. I will say I noticed my bike gets filthy around the filter...

 

[vroom]

I noticed my breather tubes were spitting hot drops of oil directly onto the IAT sensor. I believe this was causing the sensor to read too hot and leaning the mapping. If the engine is at 400 degrees F so is the oil, and if the hot oil gets onto the IAT sensor it will screw up the reading. This, IMO, was a big problem with my bike. I noticed a big difference by just blocking the IAT from oil splatter from the breather tubes.

If that is indeed the case, that makes a lot of sense(as it relates to causing problems). I hadn't thought of that.