Vroom scooter won't go over 30

[ram_man]

I picked up a vroom scooter. It's a gyc 150cc which I understand is a common Chinese small engine. It was free from my mother in law. I put a new battery in it and cleaned the carburetor jets. Starts runs and goes but will not pull a hill and on flat ground will only do about 30mph. I believe it should do about 60mph. It isn't at redline and going 30 mph either... I'm learning all about these things but I'm a newb. There is also a vacuum line /small hose coming off the back of the bike . The primary case , is that what that is called? Not sure where that goes on the engine all help is appreciated.
Items done
New battery
New oil
Cleaned carb, removed Jets and cleaned them.
New ngk spark plug and fresh premium fuel

 

[Chris142]

Some small bikes come with a restrictor in the exhaust. Usually its where the pipe bolts to the head.

 

[skyactiv]

Get rid of that thing before you get hurt.
Having flipped a bike or 12 in the past for profit, I'd look into the transmission. Something cheap and simple is wrong I bet.

 

[ram_man]

Originally Posted By: skyactiv
Get rid of that thing before you get hurt.
Having flipped a bike or 12 in the past for profit, I'd look into the transmission. Something cheap and simple is wrong I bet.



What am I looking for in the transmission? I'm not real familiar with how the transmission works on these things.

 

[skyactiv]

Originally Posted By: ram_man
Originally Posted By: skyactiv
Get rid of that thing before you get hurt.
Having flipped a bike or 12 in the past for profit, I'd look into the transmission. Something cheap and simple is wrong I bet.



What am I looking for in the transmission? I'm not real familiar with how the transmission works on these things.


Some scooter come restricted when new. Find it on Youtube. Easy peasy. Or it could be worn sliders or something else.

 

[ram_man]

Originally Posted By: skyactiv
Originally Posted By: ram_man
Originally Posted By: skyactiv
Get rid of that thing before you get hurt.
Having flipped a bike or 12 in the past for profit, I'd look into the transmission. Something cheap and simple is wrong I bet.



What am I looking for in the transmission? I'm not real familiar with how the transmission works on these things.


Some scooter come restricted when new. Find it on Youtube. Easy peasy. Or it could be worn sliders or something else.
it used to run 60mph my mother in law used to ride it all the time. Now it goes 30 -35 and is sluggish...... I popped the cover off the transmission and the belt moves back and forth freely on both ends as it's revved up it appears to be working correctly. Should I pull it apart and check the rollers?

 

[spasm3]

I would check the rollers in the variator. And check the springs in the clutch. Put a new belt on it. Very few 150cc scooters will run 60mph stock regardless of what the speedo says. Most scooter speedometers read 5-7 mph faster than you are really going. A kymco super 8 150 will do 60 as will an aprilia. Most generic chinese 150cc scooters will do around 52-54mph.

 

[ram_man]

Originally Posted By: spasm3
I would check the rollers in the variator. And check the springs in the clutch. Put a new belt on it. Very few 150cc scooters will run 60mph stock regardless of what the speedo says. Most scooter speedometers read 5-7 mph faster than you are really going. A kymco super 8 150 will do 60 as will an aprilia. Most generic chinese 150cc scooters will do around 52-54mph.


The rollers looked ok. They are round and not oblonged. I don't know if they've ever been done or not though......the belt is a Gates and looked ok but once again that could be original for all I know. I hate to throw money at it . But would that make sense that it would run up to 7,000rpm in the air but while riding wont wind out? It doesn't miss or run bad just simply feels topped out.

 

[Brybo86]

I would check rollers,
Does trans rollers and rear clutch move correctly if it is on the stand with cover off?
Drive it around with the cover off and watch the movement
how many miles....valve adjustment?,
I would ask your mom if it lost power gradually or overnight, what were the circumstances.... Mb too big of a belt, I would be really surprised it oem belt was a gates

 

[ram_man]

Originally Posted By: Brybo86
I would check rollers,
Does trans rollers and rear clutch move correctly if it is on the stand with cover off?
Drive it around with the cover off and watch the movement
how many miles....valve adjustment?,
I would ask your mom if it lost power gradually or overnight, what were the circumstances.... Mb too big of a belt, I would be really surprised it oem belt was a gates



Yea both the clutch and the rollers moved correctly...... How much slack should the belt have? It has 5,000 miles I don't know if it's had a valve adjustment.

 

[macarose]

Take it to a motorcycle shop and have them look at it.

 

[ram_man]

How could I tell if the belt was stretched

 

[lars11]

Now, if it used to go 60 and now 30, something changed. So it's not the variator weights, not the exhaust, not the carb nozzles.
I got a 50cc variety of the GY6 for free and it was hard to start and very weak, so we cleaned the carb, changed the plug, replaced a cracked vacuum hose etc etc.
No change but the manual stated to adjust the VALVES at like 5000 km. Easy peasy, they were out of range and after adjustment: The scooter did the advertised 50 km/h!!

So if it has spark, clean carb (electric choke ok) and has done a couple of thousand miles; adjust the valves. Youtube has all the tricks that makes the job a quick one!