Engine breather routing on '10 FE450

markvfr said:

Quick question for you guys. What is the crankcase hose routing on the new Bergs? I went for a ride last night and on a snotty hillclimb I got bucked on a root and did a standing vertical pirouet 180 landing facing downhill. Upon restart, my buddy told me that I smoked out the exhaust like I just blew the rings or a valve seal. I popped the air filter to see if I got oil in the airbox from the breather like they always were on my past bikes, but nothing. The smoking continued but after a nervous 4-5 mins of cautious riding, listening for any noise etc the smoking stopped. Bear in mind, this is still before my first oil change.
So, our theory is that when the bike went vertical for a split second the overfilled (my guess since it looks like the level on the sight window is way above the top) oil from the dealer, it somehow made it into the intake. Is the breather hose routed behind the air intake ie I didn't see any oil in the airbox?

Any input would be great.

Thanks
Mark

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Ahhh... you have experienced one of the joys of the 70-degree engine layout. I experienced the same thing after having to bull-dog my FE 390 down a nose-bleed slope for about 20 minutes. The slope was so steep that once or twice I had the rear end of the bike straight up in the air ... waving around threatening to fall on my head. But got lucky and no drama. whew!

Got down to the bottom and experienced the same mosquito-abatement impersonation that you described. I also almost wet my pants as my bike was still pretty new. I thought maybe I had sucked a ring or something. But when I pulled the air filter ... air box was as clean and dry as could be.

Hmm... After much thinkin' and ponderin' ... came to the conclusion that I was pointed downhill, severely enough and long enough ... that a very small amount of oil migrated past the piston rings. Once the bike was restarted, it was immediately burned off and went back to acting totally normal. Another whew.

But here's another syndrome that you may run into. If you have run it WFO for an exteneded period of time (say, like hauling in Baja or such), you can froth up the engine oil enough ... and there's enough engine vacuum going on from the air box ... that you *can* end up with a small puddle of engine oil in the airbox. argghh

It's for this reason that some are re-routing the engine breather hoses to and outside filter.

Cheers! E-Ticket

I was out riding with some folks that were testing the 09 450 for a write up and saw a similar incident as we went down a steep canyon.

IMHO the reason this occurs is usually that the motor is over filled with oil. When I first got my bike I would drain the oil for a day, and then refill with what the "book" said was the refill capacity. I noticed that occasionally there would be a puff of blue smoke when I started it, which led me to investigate further and I discovered that the oil level was indeed too high. I corrected the oil level and no more puff O smoke on start up.

I have found that putting an initial 1 liter in is a good start with the bike on a level stand. Then wait for the oil to settle out, and then accordingly until the proper height is reached on the sight glass. Start the bike and let it warm up, then check the oil level the next day. Keep track of how much oil you put in, in totality for the rest of your changes.

Too much oil in the case causes a plethora of problems, one being smoking. Another one eluded to earlier is high speed operation for long periods. With too much oil, it will tend to vaporize more readily. This high speed operation is where the quality synthetics like Amsoil really come into their own as they resist this vaporization much better than a regular petro based oil.

As discussed in many earlier topics, keeping a slight vacuum on the engine case below the piston is a good thing, as it helps keep the rings from fluttering.

Since there is no oil in your air box in the instances mentioned in this thread, the only logical conclusion is that the oil is moving past the oil scraper ring, and compression rings. So, re routing the engine breather tube will not solve this problem. Some folks have re routed the engine breather in attempt to lower the air temp sensed by the air temp sensor in the air box to improve performance. Although I have seen no data on this procedure to support this action, in theory, the lower air temp inside the air box would tell the ECU that the air density is higher, and thus add more fuel. I have seen several other mods to achieve this, including drilling small holes on the length of the vertical sealing flange of the radiator shrouds, to the complete removal of this sealing flange to allow greater air flow into the box.

I've looped my 570 a number of times, and dropped it on its side a bunch more, including going downhill (I seem to drop it on downhills more). I have never experienced smoking or hard starting or any problems afterwards. I do occasionally see some oil in the filter compartment, but I wipe it up. I have never overfilled the oil - so it sounds like that may be the problem.

CodeMonkey said:

I've looped my 570 a number of times, and dropped it on its side a bunch more, including going downhill (I seem to drop it on downhills more). I have never experienced smoking or hard starting or any problems afterwards. I do occasionally see some oil in the filter compartment, but I wipe it up. I have never overfilled the oil - so it sounds like that may be the problem.

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I think it takes a fair bit of time 5-10-15 minutes ....(?) in the serious nose-down attitude to have any engine oil migrate past the rings. And if it is upside down for any length of time ... that can lead to a small amount of oil in the air filter box.

Beyond that ... it's overfilling ... and/or .... extended high-rpm running to drag some engine mist into, and collect in, the air filter box. As in, running WFO in Baja or at the Aussie Safari Rally.

Cheers, E-Ticket