Fuel puking out overflow line

[katflap]

Hey, if it works it works !. Just love these kind of repairs

These days my bike gets replacement parts, I reserve the hose pipe style repairs for my car

[detours]

Originally Posted by SpudRider

Thanks for taking the time to examine the oil separator, and post the photos.

Was the cap of the black bottle easy to remove? When you replaced the cap, did it snap securely into position?

No, the cap is fused onto the bottle after filter installation and is not removable. My phone camera has a macro setting and I took my pics through each end of the separator.

[detours]

Originally Posted by SpudRider

However, lower pressure also promotes the condensation of gases, as shown in the video below. Therefore, I suspect the hole in the wire mesh of the 'contaminant separator' might actually increase the condensation of fuel vapor, rather than decrease it.

Interesting. I hadn't thought about condensation effects from low pressure.

With the stock (undrilled) filter, I wonder if filter saturation from fuel causes an additional pressure drop from the reduced airflow, causing further condensation. And if so, would that cause more or less condensation than the pressure drop from the increased flow after drilling the hole.

I'm sure I'm overthinking this ... I really just need time to ride and find out if this works!

[SpudRider]

Originally Posted by detours

No, the cap is fused onto the bottle after filter installation and is not removable. My phone camera has a macro setting and I took my pics through each end of the separator.

Thanks for the explanation.

[SpudRider]

Originally Posted by katflap

Hey, if it works it works !. Just love these kind of repairs

These days my bike gets replacement parts, I reserve the hose pipe style repairs for my car
Attachment 3500

Function trumps form.



You can buy the crankcase vent hoses and contaminant separator for 35 CNY on Taobao. I have one in my shopping cart for my next order.

https://item.taobao.com/item.htm?spm...cket=12#detail

[SpudRider]

Originally Posted by detours

... I really just need time to ride and find out if this works!

I agree. This is an interesting experiment, and empirical data is always superior to theories. Ride the bike hard, and let us know the results.

[SpudRider]

Originally Posted by 3banger

Sand the molding seams off of the plug so it will positively seal in the clear plastic tube. I also put a light coating of silicon (dielectric) great around the plug to insure a good seal...

I just sanded the plug of the collecting tube at the bottom of the crankase ventilation assembly. I have never collected any fuel in the tube, but the plug smells of gasoline fumes. I will now apply some dielectric grease, and re-install the plug.

[SpudRider]

Well, I went for 65-mile ride, and I actually collected about one inch of clear fluid in the down tube. I am going to wait to see how many miles I must ride before the tube is filled with fluid. Then I will empty the tube, examine the contents, and test for flammability.

[SpudRider]

Here are some photographs, courtesy of forum member CO2, which show the design of the crankcase ventilation system.

The crankcase vent is cast into the stator cover.



The crankcase vent connects to the shaft at the left side of the engine counter balancer. The engine counter balancer is located in front of the crankshaft, and is timed to the movement of the crankshaft by gears located under the stator cover.



The engine counter balancer has a hole running longitudinally down its shaft. The crankcase vent receives contaminated gases from the crankcase via this hole in the engine counter balancer.

[SpudRider]

The crankcase is separated from the transmission by a wall, as shown in the following photographs. Here is a photo of the inside of the left crankcase half.



Here is a photo of the inside of the right crankcase half.



A small sump is located below the crankcase. It is drained by the oil screen plug on the right side of the motorcycle, which is located in front of the oil filter.

When the engine is cold, some fuel can stick to the cylinder walls, and seep past the piston rings into the oil collected in the crankcase sump. When the engine heats up, this liquid fuel turns to vapor, and is routed through the shaft of the engine counter balancer, along with blow-by gases which are expelled from the combustion chamber past the piston rings.

As you can see, it is virtually impossible for any liquid to exit the crankcase vent. Only water vapor, fuel vapor, and other contaminated vapors can leave the engine. Some of these vapors condense in the 'contaminant separator,' and the resulting liquid is collected in the down tube.

[Jay In Milpitas]

That jet to squirt oil under the piston is another nice little touch. I don't know if it's directed to hit under the dome towards the wrist pin or to merely keep the outside of the skirt lubed, but it sure shows attention to detail.

[Jay In Milpitas]

Originally Posted by SpudRider

Well, I went for 65-mile ride, and I actually collected about one inch of clear fluid in the down tube. I am going to wait to see how many miles I must ride before the tube is filled with fluid. Then I will empty the tube, examine the contents, and test for flammability.

Spud & Detours, just wondering what the difference is altitude is between you two? Without reading back through lots of stuff, it seems that folks nearer sea level like myself aren't really having much fluid collect there. At most, I've had the drain plug be slightly damp.

Can the rest of you chime in?

And ArExThree, if not lasers on your bike, maybe route the tube to a flame thrower?

[SpudRider]

Gasoline is much more volatile that water vapor, so most of the gasoline fumes remain in gaseous form, and are drawn into the air box. Most of the water vapor condenses in the 'contaminant separator,' and is deposited in the down tube. The liquid collected in the down tube is mostly water, with a little bit of gasoline, and other contaminated liquids.

[SpudRider]

I think altitude, altitude changes during the ride, humidity, length of the ride, and a number of other different factors will affect how much fuel is condensed in the down tube. As someone else suggested, it would be nice to have the contents of the down tube analyzed, to see the actual percentages of water versus fuel, et cetera.

[detours]

Had to take a break from riding cause I got the flu, but after a few rides it became obvious that drilling out the filter actually made the problem worse. I collected about twice as much liquid in the catch tube as before during my commute.

I ordered a $10 replacement from CSC a couple of weeks ago just in case and installed it yesterday. Oh well, it was worth a try.