Centrifugal Cent. Clutch: I know it's dead Jim, but maybe salvageable

[Teo McDohl]

Unnamed Chinese 4 stroke kit with a 3 shoe centrifugal clutch has broken a spring after about 5-6 riding hours. Like a derp, I rode it a little longer like that and ripped up most of the pads (grinding on the loose spring). I have a few questions.

1) What was the reason the spring broke? Could it be that I was not going full speed often enough and the slippage of being only slightly on the throttle did it? Or perhaps it was just weak? Or maybe I was too much on the throttle too often? Obviously without being all knowing this can't be determined, but I was hoping some insights to affirm or negate my thoughts could be given.

2) Will I need to replace the entire clutch due to the pad deterioration? Or just a new spring and the pads are decent to last a while? Or do replacements for the pads exist?

3) Does a better clutch exist than the 3 shoe clutch? Perhaps one that would perform better etc?


Thanks ahead of time,
Teo

 

[Teo McDohl]

So, the ebay seller replaced my clutch, and I purchased another so I could have a spare. With the broken one I now have a few extra parts so that's nice. I still would like suggestions for questions 1 and 3 if at all possible.

Thanks ahead of time,
Teo

 

[OCCStingray]

Photo of the broken bits?
Sounds like a weak spring or incorrect installation.

 

[Teo McDohl]

So here is an update. I found out which engine I have. It's the Huasheng 4 Stroke Bike Motor.

Link here for further details, but not where I bought the motor: http://www.alibaba.com/product-detail/Huasheng-4-Stroke-Bike-Motor-Kit_729256032.html

My clutch just wore down to bare metal again... after about a 1 hour ride. No spring broken, but now I see there is more of an issue than I previously thought. Perhaps the spring breaking was due to riding the previous clutch metal to metal. My question NOW is why the heck is my clutch wearing down so quickly? I use it on a few hills all while pedaling hard, I don't always have it at full throttle, I usually get a small head start by pedaling before engaging the throttle from a stop and I ease into it. Should I be fully on the throttle whenever I engage it? Is there something else I'm doing wrong? Heck it might be my weight now that I think of it. I'm 220 lbs and the bike is a street Schwinn, so fairly light I would say.

It seems, by looking at the "L" shape of the remaining clutch shoe that the bell housing doesn't fully go over the clutch. Should I not push the clutch in all the way when installing it? Do I need to put a longer screw in with a few nuts or something to pull the clutch out the 1/4 inch it seems to be too far in? Or perhaps pull out the bell housing the 1/4 inch somehow? All advice is welcome.

 

[OCCStingray]

Maybe, with the alignment issues, the clutch is unable to obtain full grip and is slipping, wearing it out quicker.
I suggest trying to have the shoes and the drum aligned before dieing anything else.

 

[Teo McDohl]

Where would I take it to get that done? Any mechanic? Additionally, anyone else have any ideas?

 

[dchevygod]

Is that a tapered crankshaft? They do make a two shoe and adaptor plate that fits on a tapered shaft. Here https://www.ebay.com/itm/271090793508

 

[dchevygod]

Easiest way to align the clutch you have is stack some washers behind the shoes or drum, does the bell move in and out at all if you pull on it? if its not a drum/mounting problem I'm stumped not being able to see it. When u install either new clutch make sure to degrease everything and scuff the drum slightly with sand paper or Emory cloth first.

 

[Teo McDohl]

The bell doesn't move in or out. I COULD do the washer stacking to bring either the clutch out or the drum in so they meet better, and of course the scuffing thing I didn't know about. Thanks for that suggestion!

 

[HeadSmess]

same clutches as found in all 49cc two stroke pocket bikes. yep, you can get upgraded ons, and a lot cheaper than the "specialised" one that the guy sells for the 4 strokes... which arent specialised at all, theyre exactly the same...

sometimes they just pop shoes. direction of rotation can be an issue occasionally. bad glue job, combined with lack of rivets. i know from using the 4poppers on RC cars that they prefer the shoes to be run "backwards". never stuffed around with them on the huasheng for too long but...


what type of gear ratio is it running? if its too high, you will be forever slipping, especially if it has the standard issue springs, which is more than likely. the two strokes rev a lot faster, and engage at a higher speed, ie, you need softer springs. spreading coils apart with a screwdriver will help.


theres no reason they should wear other than slippage. the whole assembly "floats" to a degree, making up for misalignments.

considered a seized bearing somewhere in the driveline yet?

somethings overloading it.


washers wont work if the clutch is on a tapered shaft...



and finally, they are the 2nd worse gearboxes you can get, if that alibaba one is exactly what you got.. the ones that come off the lil twostrokes, (CAG engines, 49cc mini dirtbikes these things... http://www.cn2566.com/Product2.asp?ClassID=25&classname=Mini Dirt Bike ) while externally identical other than the output shaft (splined for a sprocket close in rather than perching a sprocket on a freewheel on a 3 inch shaft...) are FAR SUPERIOR on the inside. i mean, things like shoulders on shafts so they LOCATE ACCURATELY, the amount of material allowed around the bearing bosses, so they dont just crack out in the first ten seconds, blah blah blah blah...


shame they arent a direct fit, because of that sprocket. so dont go down that avenue


you got a good engine but lousy driveline.


usually they require a 55t sprocket AT LEAST, not 44. on these boxes, on 26" rims.


the degree of offset between clutch shoes and drum is a good indication of the quality


save the frustrations. get a HT 2 stroke. yes, i like the 4 stroke feel too, but all available units are simply a compromise. until theres a dedicated 4 stroke made like a HT engine, a specific bike motor, these issues will remain.

ok, youll be replacing one set of frustrations with another completely different set...


i know a lot of people will argue against that, but me myself... i like to have my pedals the NORMAL distance apart, rather than this big awkward cumbersome THING down stairs...

even if you spend top dollar on the BEST 4 stroke mounting kit, nothing can overcome that stupid offset crank.