My first RX3 valve adjustment

[CSaddict]

Better off just using a catch can that doesn't recirculate.

[dpl096]

Originally Posted by Rodtheviking

From what I can see you just remove the little canister thingy and run the tube from the air box right to the crank case.

Yes sir that is exactly all I did.

[dpl096]

Originally Posted by CSaddict

Not sure how that is beneficial due to the oil vapor lowering the octane. That won't stop the blow by from contaminating the oil.

3banger did 500 miles and had no oil residue odor in his oil. I know my last oil change failed miserably on the sniff test so I'm willing to give this a try. My concern is the gaseous fuel is condensing at the OCS and dribbling back into the crankcase. My intention is to send off an oil sample for analysis from my next servicing. We already have posts of existing oil sample analysis to use as comparison. I run only Marathon premium fuel and God knows there are quality differences from one gas station to the next in their fuel so I'm confident the ECU is more than capable of compensating for the changes in air to fuel content.

[dpl096]

Originally Posted by CSaddict

If you plug the ocs how is the crank case relieving pressure?

The OCS is gone and not plugged. The relief port on the crankcase now runs directly back to the air box where it's my intention for it to be pulled back into combustion.

[detours]

Originally Posted by dpl096

3banger did 500 miles and had no oil residue odor in his oil. I know my last oil change failed miserably on the sniff test so I'm willing to give this a try. My concern is the gaseous fuel is condensing at the OCS and dribbling back into the crankcase. My intention is to send off an oil sample for analysis from my next servicing.

Unless the OCS fills all the way to the top of the U-bend, it won't run back into the crankcase. But something is happening to leave so much fuel in the oil. I wonder if when the filter in the OCS becomes saturated with fuel, it scavenges less efficiently from the crankcase.

I'm interested what your oil analysis turns up. If you see little or no fuel in the oil, that would really prove that eliminating the OCS and running the line straight to the airbox works at least as well as running out through the OCS. Especially if you keep an eye on the airbox catch tube.

[2LZ]

Originally Posted by CSaddict

Not sure how that is beneficial due to the oil vapor lowering the octane. That won't stop the blow by from contaminating the oil.

As I recall, no OCS and direct to the air box is the way the real Honda motor runs the tube that this engine is cloned after.

[2LZ]

Originally Posted by detours

Unless the OCS fills all the way to the top of the U-bend, it won't run back into the crankcase. But something is happening to leave so much fuel in the oil. I wonder if when the filter in the OCS becomes saturated with fuel, it scavenges less efficiently from the crankcase.

I'm interested what your oil analysis turns up. If you see little or no fuel in the oil, that would really prove that eliminating the OCS and running the line straight to the airbox works at least as well as running out through the OCS. Especially if you keep an eye on the airbox catch tube.

I'm curious to see this also. I just had posted that I think that direct to air box was how the real Honda motor used to run this line. The only reason I can think of catching any excess blowby gasses in the tube would be to help eliminate some of it from being blown on an intake sensor for the injection....but that's just a guess.

[dpl096]

Originally Posted by detours

Unless the OCS fills all the way to the top of the U-bend, it won't run back into the crankcase. But something is happening to leave so much fuel in the oil. I wonder if when the filter in the OCS becomes saturated with fuel, it scavenges less efficiently from the crankcase.

Good point Detours. There are only a couple of ways for the fuel to get mixed into the oil and to me this is a good starting point. Additionally I watched the Zongshen video and sure enough the RX3 in the video is vented direct to the airbox at 11:24 and again at 11:40.... To me that is a good indicator the OCS is something needed for the North American market and CARB/EPA come immediately to mind. Not wanting to mislead anyone .... within the same video are shots of another RX3 with (7:22, 9:05 and 12:18) the OCS installed. . . Warning .. some might find the video to be too "campy" but I thought there was solid technical and diagnostic information in it. Im a geek so I copied the vid into my trusty desktop RX3 file ... I didn't care for the little fella at 10:25 telling me I'm fat and it effects mpg

[detours]

Good find, DPL. It starts cheesy, but at 4:30, you get some solid troubleshooting info.

[detours]

Originally Posted by 2LZ

As I recall, no OCS and direct to the air box is the way the real Honda motor runs the tube that this engine is cloned after.

I read somewhere that NC250 was an original design by Piaggio, commissioned by Zongshen for the RX3 (I'll look for the link but it was a while ago). Do you have more info on a Honda clone connection?

Edit: I found these references to the origin of the NC250 but none definitively state the design origin of the engine. I'll keep looking tho, cause I'm manic that way

• http://www.chinamotorworld.com/index...a=view&id=1793
• http://en.zongshenmotor.com/?q=node/513
• http://www.chinariders.net/showthrea...=13440&page=14

[BlackBike]

Originally Posted by dpl096

Good point Detours. There are only a couple of ways for the fuel to get mixed into the oil and to me this is a good starting point. Additionally I watched the Zongshen video and sure enough the RX3 in the video is vented direct to the airbox at 11:24 and again at 11:40.... To me that is a good indicator the OCS is something needed for the North American market and CARB/EPA come immediately to mind. Not wanting to mislead anyone .... within the same video are shots of another RX3 with (7:22, 9:05 and 12:18) the OCS installed. . . Warning .. some might find the video to be too "campy" but I thought there was solid technical and diagnostic information in it. Im a geek so I copied the vid into my trusty desktop RX3 file ... I didn't care for the little fella at 10:25 telling me I'm fat and it effects mpg

This is the law enforcement coming out in you not making your move until having evidence for backup.

You Should have oil analysis with 500 miles in official ocs position vs 500 miles in direct crankcase/airbox connection.

[dpl096]

Originally Posted by BlackBike

This is the law enforcement coming out in you not making your move until having evidence for backup.

You Should have oil analysis with 500 miles in official ocs position vs 500 miles in direct crankcase/airbox connection.

That was my intention BB however ... being a muddle head I drained my oil into a catch can that has oil in it from my wife's '90 Wrangler I'm rebuilding the motor on so I screwed that up .... It hit me literally seconds after the last drop left the bike ....

[dpl096]

Originally Posted by detours

Good find, DPL. It starts cheesy, but at 4:30, you get some solid troubleshooting info.

I do not deserve credit for finding the video. A fellow RX3'r from Ohio deserves the credit.

[dpl096]

snippet from: http://www.motorcyclecruiser.com/und...rcycle-engines

By nature, all four-stroke engines require ventilated crankcases. The reason is twofold. First, when an engine is started or run at low temperatures, condensation takes place and fuel vapors migrate into the crankcase. These contaminants, essentially water and raw gasoline, mix with the oil to form engine-damaging sludge. Fortunately, once the engine reaches operating temperature the water turns to steam and the fuel remnants percolate out of the oil. As long as the crankcase is vented, either by the atmosphere or by using a positive-pressure system, these nasty byproducts are free to drift out of the engine and go their merry way without causing any harm.

With that in mind, combining it with the theory that our bikes are running too cool and possibly in need of a bypass it just makes sense to me there is a constant battle going on in the OCS with condensation and as Detours has theorized perhaps our OCS is becoming overwhelmed and some of the re-condensed fuel is dribbled back into the crankcase. My thought is by directly feeding this air/fuel vapor mixture to the airbox the suction will not allow time for it to re-condense and will be burnt up in combustion. . . . . . Thoughts ? ? ? ?

[jbfla]

Originally Posted by 2LZ

As I recall, no OCS and direct to the air box is the way the real Honda motor runs the tube that this engine is cloned after.

I'm following this topic with great interest.

But I am pretty sure that the RX3 engine is not a Honda clone.

According to Joe Berk's book, the engine is a new design delveloped by an Italian firm for Zongshen.

Regardless, the crankcase vent on my TW200 and DR650 go directly to the airbox, but they are carbureted engines, not fuel injected, if that makes any difference.

jb