New Zongshen RX3 (ZS250GY-3) Dual Sport

[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.

[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.

[Wolftrax]

Originally Posted by SpudRider

Likewise, I don't think the midpipe leading to the muffler has a catalytic converter. Am I wrong?





Please note the nice, large outlet from the muffler. I wish my two Honda mufflers had such large outlets.

It does look like a clean flow from the header through the midpipe. I'm betting the cat is in the muffler right where the midpipe inlet is. Both the CRF250l and TR650 had cats in the muffler just as I described. The Husky was easy to knock out the cats with an air hammer. The Honda is more complicated involving opening the can up and re-welding. That muffler looks like it weighs a ton!!

[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.

[Weldangrind]

Originally Posted by SpudRider

I really like the stainless steel exhaust header. I don't think this exhaust header has a catalytic converter inside it. What do you guys think?

It could. I can't figure out why else there would be a weld bead at that specific point. There is no need for welding during the bending process. Also, it looks like the diameter might change at the bead.

One won't know until a wire is pushed down the pipe.

[Weldangrind]

Originally Posted by SpudRider

Likewise, I don't think the midpipe leading to the muffler has a catalytic converter. Am I wrong?





Please note the nice, large outlet from the muffler. I wish my two Honda mufflers had such large outlets.

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.

[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.

[Weldangrind]

Originally Posted by jimjr21

Will have to put it on the flow bench and test it.

You have my full attention. Did you fabricate a flow bench?

Since you declined to answer my question about your RX-3 motor, perhaps you'll tell me about your flow bench.

[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

[jimjr21]

Originally Posted by Weldangrind

You have my full attention. Did you fabricate a flow bench?

Since you declined to answer my question about your RX-3 motor, perhaps you'll tell me about your flow bench.

I missed that.
Not from Tabao.

I have a Superflow SF-60 that will work great.

[Weldangrind]

May I ask where you bought the motor from? Top secret?

Your personal flow bench?