49cc Huasheng straight shaft clutch replacement

[Sidewinder Jerry]

Update:

I drilled the holes into the rotor, which seems to be a piece of rust; judging by how the drill behaved, it's made out of crap iron; the shoes fits the rotor, I reinstalled it on the engine and I gave it a spool, the clutch won't open regardless to how much the engine screams; I nearly had an heat stroke for nothing; I'm so done with this crap:
Screw it, and the chinese wannabe metalworker that manufactured it; time to move on either a manual belt clutch, or onto a better engine.

Whoever's reading in this topic, prior to buy a four stroke kit; do yourself a favour by steering clear from straight shaft 49cc, get yourself a tapered shaft, if the seller isn't specifying which engine you're dealing with, pepper them with questions until they spits their stuff's specs.

Sounds like unless you have a drill press and the ability to cut the keyway even; your only other option would be to take a HauSheng 142 clutch to a machine shop. They also sell HauSheng 142 replacement tappered crankshafts; which can be switched out with the straight shaft.

 

[meridianPeteJ]

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4-Stroke Clutch Flyweight for 5/8" Straight Shaft Engines | Gasbike.net

4-Stroke Clutch Flyweight for 5/8" Straight Shaft Enginesfor 5/8" Straight Shaft Engines<Get Free Shipping! - Spend $39 or more on Bike Motor Parts and get free shipping on the parts in your order. Shipping charges will still apply to ite...

gasbike.net

 

[Otto Neumann]

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4-Stroke Clutch Flyweight for 5/8" Straight Shaft Engines | Gasbike.net

4-Stroke Clutch Flyweight for 5/8" Straight Shaft Enginesfor 5/8" Straight Shaft Engines<Get Free Shipping! - Spend $39 or more on Bike Motor Parts and get free shipping on the parts in your order. Shipping charges will still apply to ite...

gasbike.net

Hello there!

Between import duties and shipping, that clutch will cost me around 70-80 bucks, as I'm Italy; the last one I got was a piece of trash; the rotor was all rusty and two shoes kept locking in a tilted position, because the peg holes in the rotor had too much play, and I managed to get it somewhat working by cannibalizing the clutch that came with my engine; after that experience I don't want to try my luck, nor invest so much on those clutches again.

 

[Gordy]

Sounds like unless you have a drill press and the ability to cut the keyway even; your only other option would be to take a HauSheng 142 clutch to a machine shop. They also sell HauSheng 142 replacement tappered crankshafts; which can be switched out with the straight shaft.

Hello there!

Between import duties and shipping, that clutch will cost me around 70-80 bucks, as I'm Italy; the last one I got was a piece of trash; the rotor was all rusty and two shoes kept locking in a tilted position, because the peg holes in the rotor had too much play, and I managed to get it somewhat working by cannibalizing the clutch that came with my engine; after that experience I don't want to try my luck, nor invest so much on those clutches again.

I think Jerry's solution might be the best. It might cost a bit more, but in the long run it'll be easier to get parts for

 

[Sidewinder Jerry]

Is this what your looking for?

4-Stroke Clutch Flyweight for 5/8" Straight Shaft Engines | Gasbike.net

4-Stroke Clutch Flyweight for 5/8" Straight Shaft Enginesfor 5/8" Straight Shaft Engines<Get Free Shipping! - Spend $39 or more on Bike Motor Parts and get free shipping on the parts in your order. Shipping charges will still apply to ite...

gasbike.net

There really seems to be a lot of issues with that KTM clutch

 

[Otto Neumann]

Sounds like unless you have a drill press and the ability to cut the keyway even; your only other option would be to take a HauSheng 142 clutch to a machine shop. They also sell HauSheng 142 replacement tappered crankshafts; which can be switched out with the straight shaft.

Hi Jerry; I considered swapping the crankshaft, but I read in ancient thread on this forum which it's not possible, because the tapered shaft requires a different side cover than the straight shaft, and the bolt pattern doesn't match; Staton Inc is out of their tapered clutches, I may as well try later this summer to request a custom machined part.

At worse, I found a tapered shaft 142F on Aliexpress for 200 bucks, I don't think it would be any different from the one supplied at Gasbike or Bikeberry, as in quality wise

 

[Otto Neumann]

I think Jerry's solution might be the best. It might cost a bit more, but in the long run it'll be easier to get parts for

I've been fiddling with the new transmission on AutoCAD, to use a belt as a clutch, putting it in tension with a swinging tensioner, operated by a 2 stroke clutch lever; a belt would last much longer than a clutch.

 

[Gordy]

I've been fiddling with the new transmission on AutoCAD, to use a belt as a clutch, putting it in tension with a swinging tensioner, operated by a 2 stroke clutch lever; a belt would last much longer than a clutch.
View attachment 216485

That's not a bad idea. A lot of early motorcycles and home made machines used that style of clutch system. The bikes we build as a hobby really aren't too far off from early motorcycles.

 

[Otto Neumann]

That's not a bad idea. A lot of early motorcycles and home made machines used that style of clutch system. The bikes we build as a hobby really aren't too far off from early motorcycles.

The transmission would be made out of a laser cut 6063 aluminium sheet, hosting the rear jackshaft with a flanged FY-15TF 15mm bearing; considering its size, and the work load, and the fact which features a greasing port, it's probably going to outlast the engine itself.

Two custom machined V pulleys, with slightly oversized guides, would keep a belt confined within their radius, the belt small enough to allow a free rotation of the driven pulley; between the drive and driven pulley, would lay the effective clutch:

A swinging arm with a calculated length would sit on a couple of axial bearings for a smooth swinging action; the shorter side equipped with an idler pulley, and the longer side connected to a 2 stroke clutch lever; the system would work oppositely to a china girl's clutch, namely, the clutch would be in neutral by default, and it would be in gear when the lever is depressed and locked into position, that makes it easier to put the bike in a condition where the engine would be disconnected in either an emergency, or during regular maintenance.

Somewhere a Nema 17 stepper motor could be placed, and connected with a 5mm belt to the engine, the stepper motor makes a fine generator and would be able to supply 12V whenever the engine is running, I don't remember how many watts but should be enough to charge a small battery or to power some LED lights and a horn.

 

[Gordy]

The transmission would be made out of a laser cut 6063 aluminium sheet, hosting the rear jackshaft with a flanged FY-15TF 15mm bearing; considering its size, and the work load, and the fact which features a greasing port, it's probably going to outlast the engine itself.

Two custom machined V pulleys, with slightly oversized guides, would keep a belt confined within their radius, the belt small enough to allow a free rotation of the driven pulley; between the drive and driven pulley, would lay the effective clutch:

A swinging arm with a calculated length would sit on a couple of axial bearings for a smooth swinging action; the shorter side equipped with an idler pulley, and the longer side connected to a 2 stroke clutch lever; the system would work oppositely to a china girl's clutch, namely, the clutch would be in neutral by default, and it would be in gear when the lever is depressed and locked into position, that makes it easier to put the bike in a condition where the engine would be disconnected from the engine in either an emergency, or during regular maintenance.

Somewhere a Nema 17 stepper motor could be placed, and connected with a 5mm belt to the engine, the stepper motor makes a fine generator and would be able to supply 12V whenever the engine is running, I don't remember how many watts but should be enough to charge a small battery or to power some LED lights and a horn.

I love the thought you've put into this. Perhaps you could include a mount for a stepper motor in your backing plate. How much would it cost you to have this made?