"JL" gearbox oil / non-square gearbox sprocket

  • Thread starter StefanoDimera72
  • Start date


First off, my plans for a Yamaha TTR-50E motor fizzled when all the sudden a friend's dad had a $300 moped for sale (a '78 JC Penny Swinger 2). I brought it home but my brother and dad told me it was too nice to canabalize. Whatever, i figure when it sits for a year I'll tear into it then. So, I went to eBay and picked up a 4 Stroke Huasheng 50cc Starfire kit w/ what i think you guys call a "JL" gearbox. I also ordered new Chinese mag wheels, the ones where the sprocket is hard-mounted to the wheel. This whole eBay thing has been nothing but a nightmare, I'll go into detail at another time about that.

- I've gone thru the Search function here and am a little puzzled over what oil to add to the "JL" gearbox. The most promising seemed to be 10W-30. Anybody care to chime in an opinion?

- Also, the gearbox sprocket isn't sitting square. Definitely has a wobble to it. It's tight, the gear and shaft are straight, it's just the way it sits on the end of that shaft. Normal???? I've only fired the engine a couple short times, haven't put a chain on yet.



My primary gear is not square too, the teeth are wearing out. This is after 150km!!! Now mine is not engaging to the drive sprocket. This gearbox is garbage. I used gear oil and Lucas stabilizer but all i see when i drain the gear box out is specks of metal. I'm starting to think it was all a big waste off money. I wished I stayed with the 2-stroke


JL gearbox oil/gearbox sprocket

I've had one of these for a couple a months. I put a few hours on it with no apparent problems. My sprocket shaft spins true. If yours doesn't, I would consider it a defect and contact the vendor for adjustment. I have never put any oil in this box. I used EP wheel bearing grease on the gears. It is my understanding that the clutch is the dry type. I think that the metal in the drain oil is from the clutch which is slowly destroying itself because it is continuously slipping which also causes overheating and the smell of burnt lube.

I opened my box today to check it out and to take some pics. I can see at least 4 sets of sealed bearings, 2 for the main gear and 2 for the output sprocket. I do not see any metal particles. The box looks the same as when I greased it a couple of months ago. No evidence of anything wearing abnormally. Hope the pics are helpful.....


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Thank you cruiser66. VERY helpful. But guess I can't do a thing until I either straighten the sproket or send it back.