clutch bearings problem - Motorized Bicycle

commuter · #1 01-25-2013, 11:39 AM

Clutch started sticking and got really loud on way home other night. Pulled cover to grease bearings and found this. It's been freezing outside and I havn't really had time to dig into problem to find cause or fix. Anyone seen this before or know what I can do to get bike going again?

DIANY · #2 01-25-2013, 01:05 PM

DANG!!... havent seen this before...i hope you get help here soon...(sorry i cant help)

commuter · #3 01-25-2013, 01:05 PM

Ok, so braved the cold and looked into problem. Didn't realized big gear bearing race was just press fit onto shaft. Looks like race somehow backed itself off shaft enough to let a bearing squeak through. Found 4 or 5 bearings, or atleast that's what I think they were, that found their way into where the sprockets mesh. Have some nice circle chunks pressed into teeth now. Gonna take a bearing to work and hopefully we will have some there. Will replace the bearings and put back together.

So how do I keep this from happening again?

DIANY · #4 01-26-2013, 10:45 PM

so. do you need a press?? or can u just use a mallet????

timboellner · #5 01-26-2013, 11:46 PM

You munched the clutch bearings up good. There are quite a few of them in that clutch assembly and I'm guessing you lost and destroyed a lot of them.

Read Norm's total engine tear down about the 4th post down concerning the clutch...
http://motorbicycling.com/showthread.php?t=391

It would be far easier to just spend the $20 bucks and replace it at this point in time.
http://www.ebay.com/itm/80cc-Motoriz...item2a21dd6988

Welcome to the world of cheap Chinese engines.
TiM

UVsaturated · #6 01-27-2013, 12:58 AM

Fail they will, bearings you have!
I have had a similar situation happen to my kit. This is because of the loose quality control of some of the kits that are shipped over here from China. Obviously, it was assembled with a bad set of bearings and it came apart. Mine did the exact same thing.

I was riding along and then all **** broke loose. It sounded like everything inside the engine was grinding together, yet the engine still ran. Upon opening up my magneto cover, I saw a lot of metal particles. I did not have the clutch side bearing go out but the opposite side. Both sides are the same size. I completely tore the engine apart to inspect what had happened and wouldn't you know that there was no ball bearings at all inside the crankcase? That tell's you the shoddy nature of some of these kits and what you may deal with in buying them. You have to remanufacture them yourself or inspect them and install a good set of bearings from some of these extremely cheap suppliers, especially if it came from Ebay, or some vendor buying them from China who is just wholesaling them.

But, when I found the metal shavings, it was the failure of the bearing seal that I was finding, and the ball bearings were nonexistent. Half of them were missing. I am no rocket scientist or anything, but if the ball bearings did not physically disappear, then what happened to them?

Nevertheless, I ordered a new set of replacement bearings online manufactured in Japan I think, and that seemed to fix the problem.

I do have faith that the Chinese will endure.

maniac57 · #7 01-27-2013, 01:35 AM

Quote:

Originally Posted by UVsaturated

Fail they will, bearings you have!
I have had a similar situation happen to my kit. This is because of the loose quality control of some of the kits that are shipped over here from China. Obviously, it was assembled with a bad set of bearings and it came apart. Mine did the exact same thing.

I was riding along and then all **** broke loose. It sounded like everything inside the engine was grinding together, yet the engine still ran. Upon opening up my magneto cover, I saw a lot of metal particles. I did not have the clutch side bearing go out but the opposite side. Both sides are the same size. I completely tore the engine apart to inspect what had happened and wouldn't you know that there was no ball bearings at all inside the crankcase? That tell's you the shoddy nature of some of these kits and what you may deal with in buying them. You have to remanufacture them yourself or inspect them and install a good set of bearings from some of these extremely cheap suppliers, especially if it came from Ebay, or some vendor buying them from China who is just wholesaling them.

But, when I found the metal shavings, it was the failure of the bearing seal that I was finding, and the ball bearings were nonexistent. Half of them were missing. I am no rocket scientist or anything, but if the ball bearings did not physically disappear, then what happened to them?

Nevertheless, I ordered a new set of replacement bearings online manufactured in Japan I think, and that seemed to fix the problem.

I do have faith that the Chinese will endure.

Thats where all the shiny dust came from...ground ball bearing.

UVsaturated · #8 01-27-2013, 03:12 AM

Quote:

Originally Posted by maniac57

Thats where all the shiny dust came from...ground ball bearing.

No, that is impossible because the ball bearings are hardened steel and the crankcase is aluminum. If half the bearings came loose inside the crankcase, you would think there would be some damage, but there was none. The particles I found were the metal shield the manufacturer used to seal the bearings between the two races. It came apart. The bearing itself was faulty when the engine was assembled.