New Zongshen RX3 (ZS250GY-3) Dual Sport

[SpudRider]

Originally Posted by Weldangrind

I don't see any indications in the midpipe, but the muffler could definitely be hiding a cat. I'd be shocked if there was no cat with this bike, due to emissions regs.

If the cat isn't in the header, I'd be swapping that muffler out. It's probably really heavy anyway.

BTW, the large outlet might be for appearances only. I've certainly seen that before.

Originally Posted by Weldangrind

Spud, you may remember this old thread about Pastor Jim's scooter, where I found a cat in the muffler: http://www.chinariders.net/showthread.php?t=9421

Yes, I certainly do remember your excellent thread. I think you are probably correct, and a catalytic converter is hiding somewhere in the exhaust system. I certainly hope the RX3 muffler is not designed similarly to the scooter muffler you dissected.

[jimjr21]

There is no catalytic converter in those images. Also looks like a very nice free flowing design.

[SpudRider]

Originally Posted by jimjr21

There is no catalytic converter in those images. Also looks like a very nice free flowing design.

Thank you for your feedback, Jim.

[SpudRider]

I'm very inclined to keep the stock muffler. It should be easy to remove the end cap and check for any obstructions to exhaust flow. If necessary, I think it will be easy to modify this muffler. The large end cap should provide easy access for drilling a few holes in any baffle, or otherwise removing any large obstructions.

After inspecting, and possibly modifying the muffler, I am inclined to loan my RX3 to Dobeck Performance, and have them develop an EJK controller for the bike.

[jimjr21]

Originally Posted by SpudRider

I'm very inclined to keep the stock muffler. It should be easy to remove the end cap and check for any obstructions to exhaust flow. If necessary, I think it will be easy to modify this muffler. The large end cap should provide easy access for drilling a few holes in any baffle, or otherwise removing any large obstructions.

After inspecting, and possibly modifying the muffler, I am inclined to loan my RX3 to Dobeck Performance, and have them develop an EJK controller for the bike.

A controller of some sort will be required for what I plan on doing.

[SpudRider]

Originally Posted by jimjr21

A controller of some sort will be required for what I plan on doing.

Do you agree with my assessment of the stock muffler? I'm not inclined to spend money on an aftermarket muffler, especially when the stock muffler looks so good.

After inspecting/modifying the stock muffler, I will inspect the air box, and possibly enlarge the intake opening.

[Weldangrind]

Originally Posted by SpudRider

Do you agree with my assessment of the stock muffler? I'm not inclined to spend money on an aftermarket muffler, especially when the stock muffler looks so good.

After inspecting/modifying the stock muffler, I will inspect the air box, and possibly enlarge the intake opening.

Hopefully the stock airbox will meet your needs, perhaps with a simple mod.

[SpudRider]

I plan on keeping the foam, air filter element, and oiling it with BelRay oil.

[SpudRider]

After making these minor modifications, I would then submit the bike to Dobeck Performance for development of the EJK controller.

[Wolftrax]

Originally Posted by SpudRider

After making these minor modifications, I would then submit the bike to Dobeck Performance for development of the EJK controller.

I hope you do Spud. Dobeck's little black box has been the best and most versatile performance mod I've ever put on a bike.

[SpudRider]

Originally Posted by Wolftrax

I hope you do Spud. Dobeck's little black box has been the best and most versatile performance mod I've ever put on a bike.

Monday afternoon I called Dobeck Performance, and talked to the secretary. They owner and the tech guy were not in the office, so I hope they will contact me in the next few days.

[SpudRider]

Incidentally, the RX3 has a nice, large airbox. Notice the spacious, unrestricted tube leading from the air box to the throttle body. Also, the foam air filter appears to be 6.25-inches square.

[SpudRider]

I just found this Zongshen decal on Taobao.

http://item.taobao.com/item.htm?spm=...cket=18#detail

[jimjr21]

Without seeing the inside of the muffler it is hard to determine the restriction that it has. The outside shape looks like it would have a single bypass design.

Airbox is a nice large. The opening may be adequate. Will have to put it on the flow bench and test it. Design also looks good to remove water from intake.

I am not a fan of the foam type filters. Too easy to choke the air flow with excess oil.
How thick is the filter? Can find a standard K&N to drop in there if there is enough space.

[SpudRider]

Originally Posted by jimjr21

Without seeing the inside of the muffler it is hard to determine the restriction that it has. The outside shape looks like it would have a single bypass design.

Airbox is a nice large. The opening may be adequate. Will have to put it on the flow bench and test it. Design also looks good to remove water from intake.

I am not a fan of the foam type filters. Too easy to choke the air flow with excess oil.
How thick is the filter? Can find a standard K&N to drop in there if there is enough space.

Yes, I need to receive the RX3 before I can inspect the muffler. If the stock muffler is very restricted, I might consider purchasing an aftermarket muffler. However, the design of the stock muffler looks promising to me.

I apply the minimum amount of filter oil, and I get good results from foam air filters. I don't trust K&N air filters for off road riding. Since it is easier to apply sparingly, I use No-Toil oil on the conical air filters in my Honda CRF250X and Honda XR650L. It does a very good job filtering dust and allows excellent air flow, which is superior to that allowed by conventional filter oils. However, I still prefer using BelRay filter oil for flat foam filters, since it is much easier to squeeze the flat foam and remove the excess oil. Therefore, I prefer BelRay oil for the flat foam filters employed by my Zongshen ZS200GY-2, and the Zongshen RX3.

Judging from the photograph, it appears the RX3 air filter is about 1/2-inch thick.