best place for 50cc parts.

Karts of Kaos

the many mowers guy
Messages
987
Reaction score
75
Location
Wisconsin
hey guys, I have been working on a moped scooter thingy for a friend of mine. it had an interesting problem. she asked my if I would be able to take a look at it and I said sure. she had stated that it had " just stopped running" while she was riding. and then it had been sitting in her neighbor's shop for like two years. I guessing that it had a carb issue. but as I soon found out, no. it had a completely different problem. when I would put fuel in the intake it would just spit back out at me. so I took off the valve cover and low and behold, the intake valve was coming loose of the retainer and the valspring and not closing all the way. and the rocker arm was just pushing on the side of the spring. it is amazing that it did not fall down into the cylinder. so I was wondering where is the best place to get a new: valve, retainer,and spring for this engine. it is a Znen QT5-11 I believe. oh and a little side note. once before something happened and she needed to replace the piston. I don't know what but my guess would be a dropped valve. thanks!
kaos.
 

OPmini

Desert Bunnies MC Prez
Messages
230
Reaction score
33
Location
Phoenix, Arizona, United States
hey guys, I have been working on a moped scooter thingy for a friend of mine. it had an interesting problem. she asked my if I would be able to take a look at it and I said sure. she had stated that it had " just stopped running" while she was riding. and then it had been sitting in her neighbor's shop for like two years. I guessing that it had a carb issue. but as I soon found out, no. it had a completely different problem. when I would put fuel in the intake it would just spit back out at me. so I took off the valve cover and low and behold, the intake valve was coming loose of the retainer and the valspring and not closing all the way. and the rocker arm was just pushing on the side of the spring. it is amazing that it did not fall down into the cylinder. so I was wondering where is the best place to get a new: valve, retainer,and spring for this engine. it is a Znen QT5-11 I believe. oh and a little side note. once before something happened and she needed to replace the piston. I don't know what but my guess would be a dropped valve. thanks!
kaos.
try Monster Scooter parts: Scooter Parts & Accessories: Scooter Batteries, Scooter Chargers, & More : Monster Scooter Parts

that's where I get all my 50cc Chinese stuff
 

itsid

Moderator
Staff member
Messages
11,564
Reaction score
104
Location
Ruhrpott [Germany]
how do I take off the timing gear without messing up the timing?
simple.. you cannot ;)
once you touch the cam/chain or valves you MUST check and reset timing
but that's not difficult.

take the valve cover off
take the side covers off (both, cam gear and case)

take a sharpie and color in the dot on the cam gear,
move that dot to the cutout in the camgear port
by turning the stator (to it's "T" mark usually.. there's another mark on the crank case it lines up with)
mark that with your sharpie as well (as a reminder to yourself)
Now one last mark on the cam shaft itself
just draw a line lengthwise over at least one mounting bracket for reference.

now remove the chain sometimes that measn you need to remove the camgear from the camshaft..
(best practice is to immediately put it back in place in the correct orientation once the chain is off)
sometimes it's enough to loosen the chain tensioner and slip it off..

and when reinstalling everything you can just line up all your sharpie markings with the marks on the case
and it'll be where it was.
Remember to STILL make sure the timing is correct by following the manufacturers instructions afterwards,
or you risk hitting an open valve with the piston on first start again and you'd start from scratch.

refit the chain tensioner and you'd be good.

'sid
 

Karts of Kaos

the many mowers guy
Messages
987
Reaction score
75
Location
Wisconsin
ok so i got most of the parts replaced and gave it back to my friend a little while later she brought it back i found two lines that had come off so iput them back on and now it wont run at all and it has good spark. what do you think it wrong
 

Karts of Kaos

the many mowers guy
Messages
987
Reaction score
75
Location
Wisconsin
well so i was working on it today and the fuel pump will pump fuel but there does not seem to be any flowing through the filter when the line it on but it flows freely when it is off
 

Karts of Kaos

the many mowers guy
Messages
987
Reaction score
75
Location
Wisconsin
yes i think it is a diagram, but in the fuel pump because i could run the engine of of a bottle of gasoline. and also the machine was sitting for a few years so i think that the pump has a small crack in one of the diaphragms
 
Top