New Zongshen RX3 (ZS250GY-3) Dual Sport

[katflap]

Originally Posted by Weldangrind

I am a little confused by the RPM data; do you think the chart is posting both crankshaft RPM and gear reduction RPM at the clutch?

Yes I think so,
From what I see the Graph is only showing the reduced Dyno RPM ,
though the crank shaft RPM and Dyno RPM is shown in the table above.

I've never seen a Dyno in action so i'm not sure what part of the set up is monitored to get the reduced RPM

[oldqwerty]

Well, since there is so much confusion on the dyno chart, I'll explain. My background comes from university level research testing the efficiency of bio-fuels in vehicles ranging from scooters to Class 8 trucks. Please allow me to provide a quick analysis and summary: The project was cancelled because the lab work on real vehicles could find no evidence to support the notion that bio-fuels of any sort available on a viable commercial basis in the U. S. of A. reduced the use of petroleum based fuels. Frankly, EVERY commercially available bio-fuel cost society in the U. S. of A. more petroleum than it saved. I've dyno tested hundreds of real world vehicles, so I have a little experience on the matter.

SPEED: two columns, ENGINE and DYNO. These figures give engine and dyno speeds in revolutions per minute. This information is important because if the ratio of engine RPM to dyno RPM changes the test is faulty--there is slippage somewhere in the drive train or connection between the tire and dyno, if this is a rolling dyno. Modern dynos monitor said ration and if it changes a warning goes off, because slippage is heat, and excess heat can lead to fatal events.

TORQUE: This is how much FORCE the engine is generating and is the actual measurement measured by the dyno. ENGINE is the force measured by the dyno. DYNO is the actual force applied by the dyno to counteract the force applied to the dyno by the engine. There is a mathematical relationship between the ENGINE and DYNO columns (if no slippage) too complex to include here--if you need an explanation you won't get it, but if you can understand it you paid attention in algebra in high school. REVISE: This value is torque corrected to what it would be at standard temperature, barometric pressure, and humidity. Temperature, barometric pressure, and humidity all affect actual engine output, so the only way to compare apples to apples is to correct mathematically for these variables. Measured in newtons/meter, 1 n/m = 0.737 562 147 28 pound/foot (lb/ft).

POWER: A figure calculated from the amount work divided by the time it takes to do that work (in our case, torque). Watts are the standard metric unit of power. Kilowatts = 1000 watts. Americans like to express power as horsepower. One horsepower, since it is calculated from our torque measurement, = 737.562 147 28 kilowatt. Dynos do not measure power. Power is a calculation based on the formula (torque (in lb/ft) times RPM) divided by 5252 = horsepower. All the math behind the constant 5252 and conversions for other units of measure are beyond the scope of this explanation.

FUEL CONSUMPTION: kg/h is the mass of fuel that would be required to maintain this output level for one hour. Doesn't mean much in the real world unless you have a habit of running WOT for hours at a time. On the other hand, kg/kWh is vitally important. The lower the number, the more efficiently the engine is operating. A quick glance reveals this engine is probably going to be most efficient operating under load around 7000rpm. Note that peak efficiency corresponds to peak torque. This is not at all unusual. Further evidence of a well balanced selection of engine parts is the nice, smooth bell shaped torque curve. Most engines with well balanced components that work together are this way. Mucking up this balance is why so many modified engines run so crappy. Please do not succumb to that temptation unless you know what you are doing or are building a replica engine developed by someone who does know what they are doing, which is how I learned the artisan part of engine reengineering and building.

The rest of the graph is self explanatory.

Hope this helps those who didn't have the opportunity to take advanced math and physics courses in high school.

[Weldangrind]

Originally Posted by oldqwerty

Power is a calculation based on the formula (torque (in lb/ft) times RPM) divided by 5252 = horsepower.

I've read that the equation for horsepower is the reason that all four stroke engines have identical horsepower and torque values at 5252 RPM. I only presume that two strokes and diesels are the same.

[oldqwerty]

Originally Posted by Weldangrind

I've read that the equation for horsepower is the reason that all four stroke engines have identical horsepower and torque values at 5252 RPM. I only presume that two strokes and diesels are the same.

That is true because of the mathematical principle of inverse operations, and is true for all engines.

[SpudRider]

Joe Berk recently posted some more good information at the CSC Blog. He recommends applying locktite and tightening all the bolts of the exhaust system, as well as the front brake caliper. After riding about 1,200 miles on my RX3, over a variety of terrain, I am certainly going to take his advice.

He has also posted a very nice maintenance tutorial regarding the installation of the accessory power outlets for the RX3 dashboard.

http://californiascooterco.com/blog/

[oldqwerty]

Originally Posted by SpudRider

Joe Berk recently posted some more good information at the CSC Blog. He recommends applying locktite and tightening all the bolts of the exhaust system, as well as the front brake caliper. After riding about 1,200 miles on my RX3, over a variety of terrain, I am certainly going to take his advice.

He has also posted a very nice maintenance tutorial regarding the installation of the accessory power outlets for the RX3 dashboard.

http://californiascooterco.com/blog/

I saw the advice on tightening hardware, which is a rider maintenance item, anyway. We have basically become spoiled over the years as cars have become more and more maintenance free. Motorcycles have not, for the most part, but there have been a few exceptions. Very considerate of Joe to tell the truth. Try asking a typical dealer about maintenance intervals.

[jimjr21]

Also remember that as part of a typical dealers PDI they will check these items that we are finding loose and tighten them. We are each dealing with it individually. Not the outside of public eyes that normally happens.

[woodlandsprite]

Being completely new to motorcycle maintenance (new to hands on vehicle maintenance in general), I understand I should be able to find a torque table in the service guide - however was wondering if setting torque correctly on specific fasteners is more critical than others. I'm making a presumption that not all fasteners have a specific torque requirement, but I could be entirely wrong...

[SpudRider]

Originally Posted by woodlandsprite

Being completely new to motorcycle maintenance (new to hands on vehicle maintenance in general), I understand I should be able to find a torque table in the service guide - however was wondering if setting torque correctly on specific fasteners is more critical than others. I'm making a presumption that not all fasteners have a specific torque requirement, but I could be entirely wrong...

Every bolt does have an optimum torque, but the torque for every bolt is not always listed in every service manual. The torque for some bolts, especially larger bolts, is definitely more critical than others. For example, you should certainly refer to the service manual when tightening the flywheel bolt, cylinder head bolts, et cetera. However, tightening the small bolts on the crankcase covers, et cetera, is frequently done using the 'goodentight,' or 'German Torque' method. In other words, tighten it well, both don't overdo it. After working on motorcycles for a while, most people develop a 'calibrated wrist' for the smaller bolts and fasteners, such as the one used to secure the body side covers, et cetera.

[oldqwerty]

The first tools a newbie to wrenching motorcycles should buy are 1/4 and 3/8 torque wrenches and a hand impact with JIS bits. If you can't find JIS bits you can convert Phillips to a functional JIS imitation by grinding the tip off the end of the cross. Google JIS vs. Phillips. These tools and the ability to use them will save the novice motorcycle mechanic time and money far exceeding their cost up front. Camming Phillips screwdrivers and destroying screw heads is hassle enough, but stripping threads from holes in engine cases is a nightmare.

Over time I replace all JIS cross point hardware with stainless Allen head on every bike I own. You can guess the reasons pretty easily.

[woodlandsprite]

Originally Posted by oldqwerty

Google JIS vs. Phillips.

Thanks SpudRider & Qwerty

Qwerty - I don't have the bike on hand yet (or my torque wrenches, all are on order pending delivery), but it seems like the RX3 has phillips heads on them instead of JIS, unless CSC is calling out the wrong tool in some of their blog posts :P

[G19Tony]

I want to get a little more fuel on the bike for emergencies. I purchased some tubes from Tractor Supply, I believe it was. I had to modify the tab on the tube to fit the left pannier. I drilled 5/16 holes and used bolts with thin nylock nuts. I also used washers between all three plastic surfaces.

I'm contemplating putting one on the right side, with some of silver exhaust barrier on the tube, or, underneath the top box on the right side.

[SpudRider]

Originally Posted by G19Tony

I want to get a little more fuel on the bike for emergencies. I purchased some tubes from Tractor Supply, I believe it was. I had to modify the tab on the tube to fit the left pannier. I drilled 5/16 holes and used bolts with thin nylock nuts. I also used washers between all three plastic surfaces.

I'm contemplating putting one on the right side, with some of silver exhaust barrier on the tube, or, underneath the top box on the right side.

Very nice.

That modification is creative, functional, well-planned, and aesthetically pleasing.

[Weldangrind]

Originally Posted by G19Tony

I want to get a little more fuel on the bike for emergencies. I purchased some tubes from Tractor Supply, I believe it was. I had to modify the tab on the tube to fit the left pannier. I drilled 5/16 holes and used bolts with thin nylock nuts. I also used washers between all three plastic surfaces.

That's a neat idea. I'm using the same manual canisters with MSR cans, but my canisters are mounted horizontally, on top of a cheap trunk. They look like JATO rockets.

[G19Tony]

Originally Posted by SpudRider

Very nice.

That modification is creative, functional, well-planned, and aesthetically pleasing.

Thank you for the kind words, Spud.