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Since you have succeeded in gaining access to your engine, now you should be able to see into the throttle body bore.
Does it look "well lubricated" ? (Oily).
IF the oil is being consumed via the air filter box, I would expect it to be.
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2006 Burgman 400 - Silver - 8600 miles - and climbing !
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Discussion Starter · #4 ·
Since you have succeeded in gaining access to your engine, now you should be able to see into the throttle body bore.
Does it look "well lubricated" ? (Oily).
IF the oil is being consumed via the air filter box, I would expect it to be.
View attachment 101924
Blue, good call !

Yes it was very oily with motor oil.

It was most obvious at the bottom of the rubber elbow as it turns into the Throttle body bore:

A wee puddle, at the very bottom edge.

I licked my finger and what do ya know, it tasted the exact same as the stuff in the crankcase !

(With, perhaps, a hint of Unleaded..)

Should I put her back together & give her a road test ?

David

PS: I may try to see if I can raise the breather filter a bit higher up.
 

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I suspect the source of the problem is in the jets and cylinder/piston temps.

Oil is directed at the underside of the pistons for cooling. If the piston/cylinder runs hot or the volume of oil used is too low too high viscocity you get hot oil at that location.
This will evaporate off volatile components from the oil.

As the more volatile parts of the oil evaporate it leaves behind the “heavier” components (other than those carried separately as “mist”) and will burn off with less fowling than full oil.

Motorcycle and scooter oils or designed resist high temps/low volume issues.

The K7+ use Nikasil linings which generally run cooler and dissipate heat better
 

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Discussion Starter · #6 ·
I suspect the source of the problem is in the jets and cylinder/piston temps.

Oil is directed at the underside of the pistons for cooling. If the piston/cylinder runs hot or the volume of oil used is too low too high viscocity you get hot oil at that location.
This will evaporate off volatile components from the oil.

As the more volatile parts of the oil evaporate it leaves behind the “heavier” components (other than those carried separately as “mist”) and will burn off with less fowling than full oil.

Motorcycle and scooter oils or designed resist high temps/low volume issues.

The K7+ use Nikasil linings which generally run cooler and dissipate heat better
Ok, I'll defer to your obviously greater knowledge of the factors at play.

About the only thing I see I COULD change is to decrease down to the the 10w/40 viscocity in either a Dino or Syn Motorcycle specific oil.

(I have been using 20w/50 Motorcycle Specific Syn oil for the last 4,000 + miles.)

TY - David
 

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Discussion Starter · #8 ·
100% agreed.

Another question: can any of you say if there is a built in orifice / valve in the PVC line I'm blocking off ?

It looks like a standard 7/16" hose by appearance.

If there is such a thing, does it reside in the connection port on Airbox ?

I "THOUGHT" I read that somebody had relocated it in a longer hose but that doesn't make much sense looking at things now.

TY - David
 

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Discussion Starter · #9 ·
Ok did more research & found a great prior thread, on oil loss in 400 Burgmans.

The best posts in this thread are #10 - 15 from members cliffyk & GK13.

Both mention concrete solutions.

cliffyk custom made an insert that was an orifice restrictor to fit into PCV hose @ crankcase OD of 12mm, length of 12mm, then center drilled into it from either end using a 1/4" bit until most way through but leaving a "web" of maybe 3mm thick then drilled a super small hole of .050" thru that (1.25mm hole) to make an orifice that gas pressure can pass thru, but oil vapors can't.

So his PCV hose is connected yet restricted to 1.25mm passage.

He claimed it solved engine oil consumption issue.

Next GK13 said he disconnected PCV hose from Airbox & capped Airbox hole.

Then he put an Automotive type PCV valve fit into the PCV hose coming from crankcase vent, and the auto PCV valve terminated the assembly.

He said it solved the Oil Consumption issue as well.

He said you could hear it clicking with engine pulses / RPMS.

So that's some more for me & others to chew on.

I'm going to look into adding an Auto PCV valve into my new longer PCV hose, before that Breather Filter.

All that was found that here:


Cheers - David
 

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Just saw this, honestly I don't believe that's going to work, it looks like the hose leaving the crankcase is taking a downward path :unsure: and then going up to filter, in other words there's a low point where oil will puddle and possibly blow out the filter, my suggestions were an upward slope to prevent this and filter as high as possible. Neither were met.
IAC, good luck🤞
 

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Discussion Starter · #11 ·
You may be right.
Problem is, there isn't really anywhere "up" to go to.

I'm open to suggestions.

The only "up" option I see is if you place it outside the bodywork OR inside the trunk - neither of which sound good.

Per that thread I linked above, one user GK13 just added an Auto PCV valve to the end of the small existing crankcase port hose (+ blocking Airbox port) and said "it solved my oil usage issue".

So, I'm modding my plan, by adding an Auto PCV valve immediately below Breather Filter, in end of longer PCV hose.

Should have same / similar effect that GK13 describes.

Test, ongoing....

TY - David
 

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Hey y'all:

Ok, I'm almost ready to road test this.
Tupperware is still off but the PCV re-route is finished.

Here's my YouTube overview:


All comments & feedback welcomed -

TY - David
You may be right.
Problem is, there isn't really anywhere "up" to go to.

I'm open to suggestions.

The only "up" option I see is if you place it outside the bodywork OR inside the trunk - neither of which sound good.

Per that thread I linked above, one user GK13 just added an Auto PCV valve to the end of the small existing crankcase port hose (+ blocking Airbox port) and said "it solved my oil usage issue".

So, I'm modding my plan, by adding an Auto PCV valve immediately below Breather Filter, in end of longer PCV hose.

Should have same / similar effect that GK13 describes.

Test, ongoing....

TY - David
why did
You may be right.
Problem is, there isn't really anywhere "up" to go to.

I'm open to suggestions.

The only "up" option I see is if you place it outside the bodywork OR inside the trunk - neither of which sound good.

Per that thread I linked above, one user GK13 just added an Auto PCV valve to the end of the small existing crankcase port hose (+ blocking Airbox port) and said "it solved my oil usage issue".

So, I'm modding my plan, by adding an Auto PCV valve immediately below Breather Filter, in end of longer PCV hose.

Should have same / similar effect that GK13 describes.

Test, ongoing....

TY - David
[/QUOTE
Hey y'all:

Ok, I'm almost ready to road test this.
Tupperware is still off but the PCV re-route is finished.

Here's my YouTube overview:


All comments & feedback welcomed -

TY - David
Thanks for the video, David. I'm gonna wait to see how the oil consumption is affected before I go to modding. May I suggest running the numbers on oil consumption how you have it set up now. Then add the PCV valve. On a side note. Your frame looks like you repainted it? I have a bunch of surface corrosion on mine. I may need to address it.
 

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Discussion Starter · #14 ·
In the post you link. A member says he alleviated the issue by making an insert with a restricting orifice of .050" . He used aluminum. I'm thinking I can 3d print one. PETG melts at 260C. . I think the temp on this breather line should not get so high
Well that would be great. You'd probably have no problem finding guys to test or buy them, I'd bet.

Not sure on temps but probably not that high as you say.

260c = is how many degrees ?

The orfice restrictor is a solid idea.

I'd do that but I have new PCV valve here so in it goes for the test.

Both those members reported success by either method.
 

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Discussion Starter · #15 · (Edited)
Ok, I've added a PCV valve to my "Test Assembly" in-between new longer hose & Breather Filter.

Used a MicroGuard PCV 179 - straight unit that perfectly fit 7/16" hose & 3/8" Breather Filter entry.

Now it sounds very different.
No longer a hiss-hiss but a rhythmic clicking.

I'd be BLESSED if this puts the "Oil Consumption @ Hiway Speeds" issue to bed.

In my research, some had much higher rates of consumption than mine, mine was not too high but even 1 Qt each 1750 miles was worrying.

Here's some pics.

It's mounted as high as I could locate it.
I've tried to incorporate each suggested improvement.

The reducer orfice plug idea, being the one exception not implemented.

If this "Longer Hose + auto PCV valve + Breather Filter" mod doesn't improve things, I'll try that "Orfice Plug" idea.

Stay tuned....

TY - David
 

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Cliffyk was an excellent engineer and very helpful. If he was still alive he'd chime in and offer up some updates. 👼
 

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A few comments, piggybacking pieces of completely different ideas, may not be wise. especially when each one is not implemented/installed as designed. IMO any fix that involves restricting airflow in/out crankcase is not a great fix, it could affect engine performance and gases will find another way out, maybe not pretty o_O.

With all that said, I hope you prove me wrong, good luck :cool:(y)
 

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Discussion Starter · #18 ·
ZRX, appreciate your caution !

To know their fix suggestions precisely, one should click that thread link above & read posts 10 - 15 a back & forth from CliffyK and GK13, both of whom claimed their different approaches had "solved the excess hi speed oil consumption problem".

Now, I am assuming, and I think we can assume nothing else, that neither member had his Scooter engine fail as a consequence, logic suggests they kept running fine.

In terms of restricting crankcase output - I can blow thru the PCV from crankcase side but not from intake (breather filter in my case) side.

So I don't think this will cause a rise in crankcase pressure.

Leastways, nowhere near as much potentially as Cliffyk's Fix - which was to narrow down the 11mm diameter PCV hose to a 1.25mn restricted passage, a reduction of approx 8x.

Yet He claimed it allowed passage of gas pressure but stopped oil vapor, hence eliminateing oil loss, the goal of this project.

GK13s approach was to add a PCV to meter - regulate output from crankcase & to remove Intake Tract Vacuum as a factor that may be, in OE configuration, literally sucking Oil Vapor OUT of crankcase, perhaps more than would otherwise be pushed out, absent that influence.

GK13 said his PCV was clicking away in sync with engine RPMs. That's how mine sounds now.

Adding the Breather Filter is mainly for insurance that gasses pass without chunks present.

GK13 didn't apparently bother to use one, he just terminated at the PCV valve itself.

As Dave J noted above, Cliffyk isn't with us any longer to comment and GK13s status is unknown.

I do appreciate your well wishes.

I feel compelled to remedy this cause while I was impressed with the Burgmans remarkable Performance on my extended Tour, the constant worry over running out of lube detracted from my peace of mind.

Here's hoping I don't cause other problems lol

David in Texas
 

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To know their fix suggestions precisely, one should click that thread link above & read
I read those threads (and many others on the topic) years ago, when I was researching the Burgman 400, before buying one, none of those fixes were 100% convincing/effective in my opinion at that time :unsure:. In any case, the oil use was one of the issues on turned me away from buying a pre-07.

In terms of restricting crankcase output - I can blow thru the PCV from crankcase side but not from intake (breather filter in my case) side.

So I don't think this will cause a rise in crankcase pressure.
Yes, you may be right, in actuality the PCV is acting like a check valve, creating a vacuum or low-pressure condition in the crankcase, that is actually common/desireable on single cylinder utility engines, like lawn mowers, etc. Why not do same/similar on a single cylinder motorcycle engine? :unsure: This video explains it better ...



Yet He claimed it allowed passage of gas pressure but stopped oil vapor, hence eliminateing oil loss, the goal of this project.
Vapor is the "Gas Phase" of a liquid (and even solids) that are suspended in air, how exactly a restrictor would separate air from oil vapor is a mystery in itself, thus eliminate/reduce oil loss :unsure:, one thing for sure, a .050/1.25mm would really hinder the engine breathing.

Thinking about your present setup, it looks like is generally good, but the location is still too low, IMO. This guy had a slightly different idea, not sure about the home-made catch can or if it worked or not :unsure:, but his routing and location is better for oil to drain back, elevation, down slope and gravity are your friends.
 

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A few bikes come from the factory with a 'Catch Can' installed.

The unit I installed on my 1994 Subaru Turbo Wagon I had the PVC's run into the top and the drain down to the turbos oil return pipe. This kept oil out of the manifold.

For my 2006 Outback XT trubo I have an "Oil to Air' separator can. The oily air is spun around fast and the oil is heavier so it spins to the outside and spirals down. $195 from Perrin tuning. You may cobble up one from a BMW car cheaper off Ebay.

Edit, Perrin separator is now $485. Cylinder Gas Font Machine Magenta
 
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