Hs 49cc 4 stroke and EZ Qmatic

GoldenMotor.com

MotorizedEtc.

Member
Jul 10, 2010
159
0
16
Fremont, CA
So first some info before the problem.

HS49cc 4 stroke engine with EZ Qmatic drive
Engine has sat for about a year unused
gas is around a year old
last thing I did before not using it for a year was a valve adjustment
rear 62 tooth sprocket
just installed the flex pipe exhaust from Quenton
Just installed copper fuel line and sediment bowl
original spark plug


My problem is that the clutch does not seem to engage or engages very little. The engine runs ok from what I can hear but I have no way of telling the rpms. I took apart the clutch and every thing looks ok, but I'm no expert. spring was intact, shoes look ok, bell has a little/normal? wear but i dont think its significant. The belt doesn't seem to be slipping as it is turning the rear pulley. Only thing i noticed was the front pulley has a tiny wobble, not sure how it got there. I am leaning toward it not having enough rpms but not sure if thats the cause or how to fix it. Any help is appreciated, Thanks.
 

WightBoy

Member
Aug 30, 2012
271
0
16
Michigan, USA
Have you contacted Quenton? How many miles are on the clutch? I am thinking that maybe the clutch could be sticking at the pivot points on the shoes. You may have to take it apart and clean up the clutch.
 

MotorBicycleRacing

Well-Known Member
Jul 28, 2010
5,844
109
63
SoCal Baby!!!
www.facebook.com
Have you contacted Quenton? How many miles are on the clutch? I am thinking that maybe the clutch could be sticking at the pivot points on the shoes. You may have to take it apart and clean up the clutch.
There are no pivot points on a MaxTorque clutch.

The 6 segments are thrown outwards by increasing the RPM's.

The only adjustment would be the strength of the spring on a
Q Matic.
 

ocho ninja

Member
Jan 14, 2012
564
2
16
San Jose, CA
Might be also that old gas dried up in the carb, and old fuel residue has gummed up all the slow jet and main jet... probably need a whole carb clean out.

Had a similar thing with a customer, he though the clutch wasn't engaging but it was just the motor cutting cause of the gummed up jets.

Also make sure you have the choke if the off position when trying to run lol
 

miked826

New Member
Aug 6, 2011
1,748
7
0
Los Angeles
So first some info before the problem.

HS49cc 4 stroke engine with EZ Qmatic drive
Engine has sat for about a year unused
gas is around a year old
last thing I did before not using it for a year was a valve adjustment
rear 62 tooth sprocket
just installed the flex pipe exhaust from Quenton
Just installed copper fuel line and sediment bowl
original spark plug


My problem is that the clutch does not seem to engage or engages very little. The engine runs ok from what I can hear but I have no way of telling the rpms. I took apart the clutch and every thing looks ok, but I'm no expert. spring was intact, shoes look ok, bell has a little/normal? wear but i dont think its significant. The belt doesn't seem to be slipping as it is turning the rear pulley. Only thing i noticed was the front pulley has a tiny wobble, not sure how it got there. I am leaning toward it not having enough rpms but not sure if thats the cause or how to fix it. Any help is appreciated, Thanks.
Pulley wobble? Check and make sure the shaft key is there and not sheared off or completely missing. Turn the pulley by hand and make sure the engine shaft is turning with it.
 

MotorizedEtc.

Member
Jul 10, 2010
159
0
16
Fremont, CA
Checked and the key was there I tightened it up. I took the carb apart and cleaned it with carb cleaner, dried it, and put it back on. I started it up and once it got running the choke seems to like to be in between the on and off for best running. I thought maybe its getting to much air so i blocked off the extra holes i drilled in the air box. It still seems like its not quite getting the rpms it needs. I lifted the rear tire and it will spin it but if i keep it on the ground it wont budge at all. A couple times i did hear it reach a higher rpm for a second so my next thing to try is new gas.
 

MotorizedEtc.

Member
Jul 10, 2010
159
0
16
Fremont, CA
I dont know how to take the jets out, is there a diagram? I didnt try the wire trick, I just sprayed it really well with the float bowl off at all openings. I did a valve adjustment a year ago before i put the engine away. It is possible i did it wrong, would that effect the rpms in this way?
 

ocho ninja

Member
Jan 14, 2012
564
2
16
San Jose, CA
If you watch the video it shows how to get to the slow jet and how to clean it... and the main jet simply screws out with a flat head screw driver. Pretty easy
Carb cleaner is not good enough to get that dried on residue out... Which I think is the source of your problem.
these lil carbs get clogged pretty easy and running a good inline filter helps alot... but even with that they still tend to clog up over time
 

MotorizedEtc.

Member
Jul 10, 2010
159
0
16
Fremont, CA
Well i took it apart again and thoroughly cleaned the jets with a thin wire. put it back together and started it up. idles better now and gained a little power. However it still does not have any get up and go like I expected with a 62t rear sprocket. I even tried using a simpler fuel line instead of the copper line and loop( it sounded like it was starving with the copper setup). So i actually was able to ride it pedaling really fast and got it up to maybe 15mph and it wont go any faster. It has zero off the line pull and even with no rider on it. So next I will consult Quenton when I can, but if I cant get it running right then I think I have to move on to a different engine and transmission setup.
 

azbill

Active Member
May 18, 2008
3,358
5
38
63
Fountain Hills, Arizona
is the clutch slipping ???
could there be anything that got on the shoes ?
mine did that once when I got oil on the shoes
(I tried oiling the bushing while the engine was turning)
 

MotorizedEtc.

Member
Jul 10, 2010
159
0
16
Fremont, CA
I will take the clutch apart again for like the 3rd time lol. This time I will take pics and you guys can tell me if you see a problem. The last time i opened it up there was no oil on it, however i did just oil it so it could have some. I am going to look up how to adjust the valves as well.