Zongshen RX3: Oil Lubrication System Maintenance

[SpudRider]

Here is a video which describes how a trochoidal (gear) pump works.

[keithmaine]

Pretty awesome

[sebsanch]

Thanks SpudRider for such a fully depicting post. It's really easy to understand it even for me, having so little knowledge of mechanics and engines.
Do you know if there is a port for an oil pressure sensor in this engine?
It happens that those plastic gears that actuate the pupms shaft break, and there is no way to realize it untill it is too late. An Oil pressure sensor would be of great help in this case.
Thank you in advance.
Kind regards.

[SpudRider]

Thank you, Keith.

[Co2]

Last topics great, all scheme work prensibe's maintenance tips..

What u think, on future oil coolant system product for zs177/nc2550 radiator coming?, because bike water cool system work good, but i feel if use performance use/high rpm, oil very very hot degres(clutch,plastic gears pumps probably damaged.), this bike need a radiator oil cool system ( Cg series have oil cooler system kit, i hope kit oil system for zs177/nc250).

(sorry ,Stickly thread message, just a idea for " oil cooler system radiator " , free delete/ remove please.)

[SpudRider]

I haven't seen any oil coolers designed for the RX3. My used oil is always in excellent condition, so I don't see a need for an oil cooler on my bike.

[Co2]

Performance using ^^ high rpm( probably 8 - 10.000) , onroad and bit dirt enduro use, feeling really hot oil, ofccourse RX3 is not dirt/hard endurance chasis, and weather here sometimes summer 40°+ centigrate celsius, and asphalt to probably 50°+, and in city tarffic lamps stop/go go/stop many time, feeling after stop, very hot oil, i hope on future product a oil cooler kit.

[detours]

CO2, those are some really high temperatures. I would use a synthetic oil in that heat and consider a 10w-50 or 20w-50 oil.

[SpudRider]

Welcome, and thanks for the kind words. It's nice to see a polite person join us.

At the moment I can't think of any convenient, robust manner to connect an oil pressure sensor, since the NC250 engine doesn't have an external oil pipe. However, I'm sure someone will correct me if I am wrong.

Nevertheless, I wouldn't worry about the plastic gears which drive the oil pump. If my memory serves me correctly, all my motorcycle engines employ plastic gears to drive the oil pump, and I have never had any problems with these gears. In fact, I have never even noticed significant wear on any of these plastic gears. I doubt the NC250 engine will be an exception in this regard.

[Juanro]

This happened recently to a fellow RX3 rider here in Argentina and it triggered a mild paranoia about plastic gears.

[Jay In Milpitas]

Originally Posted by Juanro

This happened recently to a fellow RX3 rider here in Argentina and it triggered a mild paranoia about plastic gears.

Thank you for sharing that, Juanro. I see some interesting wear on the bottom gear also.

It brings up many questions. Had other work been done on the engine before? How often was the oil and filter changed? What kind of oil? Etc.

For many years most American V8 car engines used plastic teeth on the camshaft timing chain and those would last more than 60,000 miles before needing replacement. I suspect this engine had something else going wrong that started the problem.

[SpudRider]

Originally Posted by Juanro

This happened recently to a fellow RX3 rider here in Argentina and it triggered a mild paranoia about plastic gears.

Thanks for sharing the information from Argentina, Juanro.

I am inclined to believe that particular plastic gear was defective. It is very common for motorcycle manufacturers to use plastic gears to drive the oil pump. Failures of this kind must be very rare; this is the first time I have personally heard of such a failure.

[Haggis]

Originally Posted by Juanro

This happened recently to a fellow RX3 rider here in Argentina and it triggered a mild paranoia about plastic gears.

That's the gear that is driven from the back of the clutch basket.
Was his clutch loose? Clutch bearings worn? This would let the clutch basket to run out radially and end up destroying that oil pump gear? Just a thought.

[Juanro]

About 5500 miles on that bike, and the owner swears it was properly serviced. I think it's a one off; the same bike had a valve cover bolt thread stripped. I chalk it up to shear bad luck.

[Juanro]

"Noisy" clutch basket seems to be a common issue; I checked mine, and it wasn't really loose, but I re-torqued it anyway (and the nut at the crankshaft end, just in case)
This guy, whom I met personally a week before this incident, reported that he found two plastic teeth in the oil pan after the scheduled oil change. Bike is low milleage (a couple thousand Km). He stopped using the bike, open it, and found the gears like that. After changing them, engine is running fine, and he reported a change in engine sound, more full, less "clunky". That's all I know.