My bike feels like something is loose in the engine.

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Mr. Minecraft

Visionary
Jan 13, 2012
349
0
0
San Diego
When I rev up my bike (HS 49cc 4 stroke) it feels like there are some parts that are not operating smoothly. It sounds like metal clinking around. It doesn't sound like this at idle, but when you start going you REALLY hear it. I actually flinch when i hear this because i know something is really wrong. I opened up the transmission, valve cover, and took off the clutch and flywheel. Everything is fine there, so now all that is left is in the engine. Do you guys have advice before i go tear into the engine?

We want the bike running smooth because we (me and my dad) were going to join the San Diego ride this time.
 

dracothered

New Member
Jul 25, 2012
973
1
0
Howell, MI.
When I rev up my bike (HS 49cc 4 stroke) it feels like there are some parts that are not operating smoothly. It sounds like metal clinking around. It doesn't sound like this at idle, but when you start going you REALLY hear it. I actually flinch when i hear this because i know something is really wrong. I opened up the transmission, valve cover, and took off the clutch and flywheel. Everything is fine there, so now all that is left is in the engine. Do you guys have advice before i go tear into the engine?

We want the bike running smooth because we (me and my dad) were going to join the San Diego ride this time.
How tight is the chain and do you only hear the sound when you put the engine under load or do you hear it when the bike is moving without the engine under load (ie coasting)?
 

Mr. Minecraft

Visionary
Jan 13, 2012
349
0
0
San Diego
If i turn off the engine and coast, down a hill for example, there is no sound other than the one way bearing clicking away. The chains are at the right tension and yes i only hear it when I give it gas. If i get up to half throttle on flat ground and stay at that speed then i cant hear it as much.
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
If i turn off the engine and coast, down a hill for example, there is no sound other than the one way bearing clicking away. The chains are at the right tension and yes i only hear it when I give it gas. If i get up to half throttle on flat ground and stay at that speed then i cant hear it as much.

Sounds like your rod may be going, as in the cap is not tight. How many times have you taken the engine apart now for no reason other than curiousity?

dnut
 

MotorBicycleRacing

Well-Known Member
Jul 28, 2010
5,844
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SoCal Baby!!!
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When I rev up my bike (HS 49cc 4 stroke) it feels like there are some parts that are not operating smoothly. It sounds like metal clinking around. It doesn't sound like this at idle, but when you start going you REALLY hear it. I actually flinch when i hear this because i know something is really wrong. I opened up the transmission, valve cover, and took off the clutch and flywheel. Everything is fine there, so now all that is left is in the engine. Do you guys have advice before i go tear into the engine?
Your oil slinger broke off.
 
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MotorBicycleRacing

Well-Known Member
Jul 28, 2010
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SoCal Baby!!!
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On this bike I have never taken the engine apart. How do I check/ fix the problems above?
Drain the oil with the motor removed and the broken off oil
slinger may come out the oil drain filler hole.

A extendable magnet stuck in the filler may work too.

scotto had a magnetic drain plug and it captured his
broken off oil slinger.

However if the rod bolts are just loose as scotto
says you will have to tear the motor down.

Running your motor when it is making funny noises is
causing more damage, shut it off! :)

I apologize for saying you should have bought a Honda
as the Huashengs are great motors.
Is your motor still under warranty?

Did you ever buy a tach?
My calculations on the gearing that Phantom Bikes set you
up with say that you are over revving your motor.

Gonna go kaboom just like T Blows bike!!! :D
Huashengs and Honda 50's don't like being over revved!
 
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Mr. Minecraft

Visionary
Jan 13, 2012
349
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0
San Diego
When I just changed the oil nothing came out when I tipped the motor upside down. This is actually my dads bike so I know he is over revving it. Which side of the motor do I open for this? How can I check if the bolts are coming loose?
 

Mr. Minecraft

Visionary
Jan 13, 2012
349
0
0
San Diego
Oh god no, of course I put oil in it o.o

I want to fix the problem because I want the engine to last and be reliable. Right.now this is not the case.
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
EDIT: Drain the oil before removing the cover! There is no need to turn the engine upside down......again....or ever.

Just pull the cover off the left side of the engine. Remember how everything comes off as you carefully remove it (the cam, pushrod towers, etc.). You will be able to see the conrod and oil slinger attached by the conrod bolts. If the bolts are tight and the slinger hasn't broken off......put it back together using a good gasket sealer on the cover gasket (after wiping it clean with MEK or similar) or replace the gasket.

Then you may want to check the valve lash and see if that's where the noise is coming from. Good luck and work patiently.
 
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Mr. Minecraft

Visionary
Jan 13, 2012
349
0
0
San Diego
The first thing I did was reset the valves. I will make a video and see if you can hear the sound.

This is my dad's bike, as i already said, and he bought it pre made from phantom bikes to surprise me ;) but since they built it do you think we should take it to them first and see what they say (as far as free repair maybe).

EDIT: Its only a month old. My bike that i built my self has no problems. I max the RPM's on every ride and ride it 3x more than my dad rides his. Yet, his is the broken one.
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
Yes, take it straight back to Phantom and get their assessment of the problem.....I'm sure they will be more than helpful in getting this matter fixed.

Call them and explain the problem before you take it to them and just be polite ;)

The first thing I did was reset the valves. I will make a video and see if you can hear the sound.

This is my dad's bike, as i already said, and he bought it pre made from phantom bikes to surprise me ;) but since they built it do you think we should take it to them first and see what they say (as far as free repair maybe).

EDIT: Its only a month old. My bike that i built my self has no problems. I max the RPM's on every ride and ride it 3x more than my dad rides his. Yet, his is the broken one.
 

Mr. Minecraft

Visionary
Jan 13, 2012
349
0
0
San Diego
Ok, Ill do this. I also found this problem with the one way bearing. I dont know what to make of it... Video almost done.
 
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Mr. Minecraft

Visionary
Jan 13, 2012
349
0
0
San Diego
So Monday I will take it to phantom bikes. Do you think they will replace the bearing as well?

EDIT: I JUST NOTICED that the sound always Is from the Pull start side. Maybe the pull start internals are making noise. I am going to start the bike and remove the pull start to test it out.
 
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dracothered

New Member
Jul 25, 2012
973
1
0
Howell, MI.
So Monday I will take it to phantom bikes. Do you think they will replace the bearing as well?

EDIT: I JUST NOTICED that the sound always Is from the Pull start side. Maybe the pull start internals are making noise. I am going to start the bike and remove the pull start to test it out.
Do yourself a favor and just take it back to Phantom Bike before you go taking it apart and then have them tell you that you messed it up.