New Zongshen RX3 (ZS250GY-3) Dual Sport

[Veteran]

Originally Posted by oldqwerty

There is a 300cc bore kit available for under $200. I'm tempted.

That's why I was asking questions about the engine; I plan on buying the big bore kit from Aliexpress and was considering buying a complete spare ZS177MM to experiment on. That way I don't pooch up the stock motor. If it worked out ok, I'd install it on both bikes, (which admittedly, although fully paid for, I won't see them until Mid-August)

250cc is fine for me but I'm a tinkerer at heart.

[SpudRider]

Originally Posted by oldqwerty

There is a 300cc bore kit available for under $200. I'm tempted.

Do you have a link to share for the 300cc bore kit?

Personally, I wouldn't alter the engine until after the two-year warranty had expired, but I would love to see the kit.

[rjmorel]

try this link Spud,
http://www.aliexpress.com/store/prod...746771916.html

I wonder how much tinkering you'd have to do to get the FI to run good when installing this kit. Seems very reasonable price wise.


Ryan called me today to let me know my Yellow RX3 will ship next Monday or Tues. WooHooooooooooooooooo!!!!!!!! rj

[SpudRider]

Originally Posted by oldqwerty

...I've never heard of a 13mm bolt. 12 and 14, yes, but not 13. Hmmm? Guess what size hole needs to be to tap for a 14-2 bolt! Yup, 12mm. Hold on a sec. ... ... ... Okay, I just ordered two taps off eBay. Once I've tapped my bars I'll mail a tap to anyone who needs one as long as they promise to pass the tool one to another Cyclone rider...

Okay, I should have said greater than 12 mm.



I might have a 14-2 metric tap. If not, put me on the list.

Originally Posted by oldqwerty

...Oh, wait! Will the end of the guard have enough material to take a 14mm hole?...

Yes, the aluminum guard will accommodate a 14mm hole. The guard is 20mm wide, and 10mm thick. The question is whether the guard can take a hit, without breaking, if you drill a 14mm hole in it.

Originally Posted by oldqwerty

...If not, I have some thread inserts that go into about a 12mm hole and they came from Advance. Advance just might lend the tools to install. If memory serves, the inserts are less than $10.

If one needs to spend about $20 for inserts and shipping, I would rather spend $40 for a black, Tusk Chub handlebar, and keep the stock handlebar for a spare.

https://www.rockymountainatvmc.com/p...%20tusk%20t-10



After playing with the fitment a little, I think the potential problems revolve around two issues.

1) The handguards must not contact the windshield at full rotation of the handlebars. After an initial inspection, I think the handguards will need to be bent back towards the handlebars to meet this criterion.

2) The stock levers will definitely need to be castrated. That is, the balls on the end of the levers will need to be cut off. I've done this before, and its not a problem. Your hands won't slip off the levers when they are contained inside handguards.

I also noticed the Chinese, big bar handlebars taper much more quickly than usual. Therefore, I think the Tusk Big Bar Adapters are not needed for the stock handlebars. I think one can install the handguards with the regular adapaters which are included with the D-Flex handguards. I will test this fitment to confirm, or deny my assessment.

[SpudRider]

Originally Posted by rjmorel

try this link Spud,
http://www.aliexpress.com/store/prod...746771916.html

I wonder how much tinkering you'd have to do to get the FI to run good when installing this kit. Seems very reasonable price wise.


Ryan called me today to let me know my Yellow RX3 will ship next Monday or Tues. WooHooooooooooooooooo!!!!!!!! rj

Thanks for the link. One would also need a larger cylinder head, wouldn't he?

Congratulations on the pending shipment of your RX3 motorcycle.

[rjmorel]

Originally Posted by SpudRider

Thanks for the link. One would also need a larger cylinder head, wouldn't he?

Never thought about needing a larger cylinder head.
I'm no rocket scientist but I'm thinking if you just used that kit and stock head it would give you a more tractable mild power? A larger piston surface area for more power ,but sending the same amount of fuel through the same head, valves and FI and exhaust ??? Would it also lower the compression ? Maybe one of you more knowledgeable persons can explain what it would do to the motor power wise. Kinda above my pay grade , rj

[SpudRider]

I took my second ride in the dirt on my Zongshen RX3. Therefore, I have added an update containing my further impressions of the off road handling of the bike, which is discussed in my ride report thread, located at the following link.

http://www.chinariders.net/showthrea...d=1#post183552

[SpudRider]

If you wish, you can also view more photographs of my ride at the following link.

http://www.chinariders.net/showthrea...d=1#post183552

[fishman10]

Hey wheres your engine guard and luggage?? ,not goint to install them? I went ahead and put them all on except substituting the stock trunk for my jc whitney one,,,cause mine will only see state forest fire roads ,but mostly commuting. Now bear in mind I LIKE this bike,,,But i do wish it had a bit more ,,it acts as if the exhaust is really clogged up,,,hope some performance upgrades come along ,,,,but should be able to ride to work for about $7.50 all week!!!! that being said i did go from a 1450cc harley softail to this ,,so some adjustment is needed ,,,lol

[SpudRider]

Fish,

I will be installing the rest of the luggage pretty soon. I first wanted to see how the bike handled without it. Right now, I don't plan to install the engine guards. I don't think they are necessary, and they weigh a lot. I suggest you remove the engine guards, and see if the bike has a little more pep.

[oldqwerty]

Originally Posted by rjmorel

try this link Spud,
http://www.aliexpress.com/store/prod...746771916.html

I wonder how much tinkering you'd have to do to get the FI to run good when installing this kit. Seems very reasonable price wise.

No tinkering at all. EFI adjusts all by itself to such relatively minor mods. Well, the MicroSquirt on my TW did once the basic fuel map was developed. Since reports are the Cyclone EFI works quite well I figure the basic fuel map is well programmed. YMMV

Originally Posted by rjmorel

Never thought about needing a larger cylinder head.
I'm no rocket scientist but I'm thinking if you just used that kit and stock head it would give you a more tractable mild power? A larger piston surface area for more power ,but sending the same amount of fuel through the same head, valves and FI and exhaust ??? Would it also lower the compression ? Maybe one of you more knowledgeable persons can explain what it would do to the motor power wise. Kinda above my pay grade , rj

I'll have a better idea once my Cyclone is broken in, but based on the reports I've heard a 300cc engine with no other changes will lose top end and gain low and mid range. A "larger" head will not be required, but I'd definitely chamfer the head to match the bore of the cylinder and new head gasket to limit the possibility of a warm edge in the combustion chamber that could cause preignition (ping). When (not if, unless a ~400cc version of equal value becomes available) I do one of these engines, I'll chamfer the combustion chamber, look at unshrouding the valves if needed, and clean up the ports and valve guides. No porting. The result is "free" torque at all engine speeds that comes from improved efficiency that reduces parasitic drag from air flow restrictions. The result is lower engine loads, a cooler running engine, and better fuel efficiency.

A mild cam would maybe shift the powerband higher, but that may not be the answer. I've run across a few engines over the years that a cam change made a slower engine because intake and exhaust restrictions limited air flow. That's really a blessing because intakes and exhausts are usually cheaper and easier than all the auxiliary components that accompany a cam install. A good example is the 2.2 in the late '90s S10s and S15s. Cold air intake, bored throttle body, coil packs, power pulleys, chip, and a decent set of headers and freer flowing exhaust turned these engines into 7000rpm Honda killers. With the stock cam. These bolt-ons in a ZQ8 suspended 2.2 5-speed truck with sticky performance tires pretty easily embarrass stock Mustang GTs and Z28s in parking lot events. Even a few 'Vettes and European hotrods fall to a well-driven 4-banger pickup truck. Even with the stock cam. Great fun on the street, too, because power improves from idle on up.

On the other hand, Yamaha did such a good job on the TW200 intake and exhaust it takes internal engine mods to make any appreciable gains across the power band. Cam and springs is the best bang for the buck on this engine. Larger displacement, major head work, and a bigger carb are necessary before there's much gain to be had from intake and exhaust mods, but if you put in enough cam at 200cc to need intake and exhaust mods your powerband will be so narrow that the rpm drop between 3/4 and 4/5 shifts will be so bad the engine wound to redline won't be in the power band after the shift, resulting in a very slow accelerating bike on the highway. The only cure is a 6-speed trans conversion using TT230 R or XT225 parts.

I haven't started investigating performance mods for this engine. I expect there are plenty because lots of other bikes and wheelers use this engine, all over the world. Anywho, on paper and from ride reports the Cyclone performs about the same as my TW adventure bike build. I expect to be happy with the Cyclone stock. If I feel the engine's stock power band is too high in the RPM range, a 300cc bore kit would be a rather elegant solution.

[pete]

Originally Posted by oldqwerty

Hey, we have to watch out for one another. Those S. O. B. (Some Other Brand) riders will start all that not waving at Chinese bikes crap.

I've never heard of a 13mm bolt. 12 and 14, yes, but not 13. Hmmm? Guess what size hole needs to be to tap for a 14-2 bolt! Yup, 12mm. Hold on a sec. ... ... ... Okay, I just ordered two taps off eBay. Once I've tapped my bars I'll mail a tap to anyone who needs one as long as they promise to pass the tool one to another Cyclone rider.

Oh, wait! Will the end of the guard have enough material to take a 14mm hole?


If not, I have some thread inserts that go into about a 12mm hole and they came from Advance. Advance just might lend the tools to install. If memory serves, the inserts are less than $10.

not seen a 13mm bolt....
but 1/2" is 12.7mm

[SpudRider]

Originally Posted by pete

not seen a 13mm bolt....
but 1/2" is 12.7mm

My goodness, yes! We should tap the hole for a 1/2-inch thread! Thanks, Pete.

[rjmorel]

" The result is "free" torque at all engine speeds that comes from improved efficiency that reduces parasitic drag from air flow restrictions. The result is lower engine loads, a cooler running engine, and better fuel efficiency."

oldqwerty, That's what my gut feeling was and you exclaimed it so eloquently. Seems like a win win situation. rj

[oldqwerty]

Originally Posted by rjmorel

" The result is "free" torque at all engine speeds that comes from improved efficiency that reduces parasitic drag from air flow restrictions. The result is lower engine loads, a cooler running engine, and better fuel efficiency."

oldqwerty, That's what my gut feeling was and you exclaimed it so eloquently. Seems like a win win situation. rj

It is win win. It's when one wants to "hop up" that the troubles start. Nothing wrong with hop-ups, I own a few myself, but they aren't daily drivers daily riders. I have a HIGHLY modified TW200 that runs with any of the Japanese 250cc street bikes including the CBR and Ninja through the rolling hills of west Tennessee and Kentucky. I expect it to blow up every time I turn the key on. So far I've been disappointed. It sure is fun, though.