1 week riding and there is a problem with the clutch.



New Member
Mar 12, 2019
I bought a second hand gas bike it for my son to commute to work on.
He's been using it about a week and today it developed an issue.
This is pretty much the kit and by pretty much, I mean everything listed in this kit is exactly what is on his bike.

huashengtaishan 4 stroke kit
HuaSheng 49cc with Centrifugal Clutch Engine (4-Stroke)
Chain Drive Centrifugal Clutch Transmission with 10 Tooth Sprocket
2.5 L Gas Tank
Gasoline Tank Switch (AL)
Fuel Line #2
Fuel Filter
Improved Wide Pedal Crank
44 Tooth Sprocket
Pineapple Bushing
Accelerograph Throttle Handle
Throttle Cable 50"
Mounting Plate
415 Heavy Duty Chain
Idler Pulley Chain Tensioner
Chain Guard


When started the bike now wants to surge forward.
:: When we first got it we could start it, and it would stand still as long as there was no throttle applied. If you picked up the back of the bike by the cargo rack the wheel didn't start spinning.

Today when I was looking at it when the motor was running I would lift the back by the cargo rack and the wheel would start spinning instantly and accelerate and you could hear the engine pitch up in acceleration.

When he was riding it everything was ok as he rode it up a hill. Not a terrible hill, about 12%grade for 1/4 mile. He said there was no problem coming up the hill, but when he got to the top it bogged down and then died. He stopped it, started started the engine and started riding and after 50 feet it bogged down again and died.

When I was looking at it and held up the back and throttled it, it seemed to run fine all the way open. I thought he was trying to baby the throttle, like the first day (which caused it to sputter and stall) but just when I was convinced he was just causing it to stall with not enough throttle it bogged down at full throttle and the clutch/transmission sounded clanky, but not grindy, and then it bogged out completely and stopped.

He's only put about 8 hours on it since we got it. I've made sure he put premium fuel in it. It got a new fuel filter and oil change the day we bought it. I watched the seller change the oil and add a new fuel filter. Nice man.

I'm pretty handy. I work on my own cars and motorcycles and lawnmowers, but I've never dealt with Centrifugal Clutch Transmission before.

What can I test - and how - to help diagnose the problem correctly. Once I know what's wrong, I'm sure I can fix it or replace it. I just don't know where to start diagnosing it.

Thanks fellas.
Last edited:


Well-Known Member
Mar 3, 2019
I'm new here too BB and not familiar with your particular equipment, but it sure sounds like your clutch is coming apart. All centrifugal's have springs that can break. I've seen the friction material de-laminate from the shoe. There was a guy on here that had his clutch drum/housing/bell thing get cut in two!

I'd go poking around in there ...