We have a lemon! By FACE PLANT FOR LIFE (Read 799 times)

[FACE PLANT FOR LIFE]

So we bought a brand new 50cc TaoTao from a dealer in Indiana, and this has been our adventure so far, leading up to us listing it for sale tonight! We really can't take this thing anymore.

- Get it home from the dealer, everything is running great! Works very good.
- Take it for a ride, again, works great
- Bike still has less than 100 miles on it - We unfortunately stressed it keeping up with traffic, pegged the RPMs as high as possible and WOT for a good 2-3 minutes on our way to Big Boy
- Get to Big Boy, notice a very...hot motor smell?
- Start it and ride it home, extreme power loss, not running correctly. Did we run it too hard??
- Get an 80cc BBK for it, tear down engine, do a complete top end rebuild..This is what we found during that:


Begin motor teardown


That's all thats left...


One of these looks...used?


Heavily scored piston? ?




Anyway, complete the top end rebuild, start it, runs great!
Once again bring it out, and end up running it hard a couple times but we tried to keep it down in RPM.
Get it home that night, its still running great.

Wake up today, go to start it, and...no start. It will only start with A LOT of gas applied. Idle screw is MAXED out and it wont even START. We have checked EVERYTHING!! Bike REFUSES to idle

Spark plug? Gapped and replaced, sparking like crazy
Carburetor? Cleaned, and then when that didn't work, REPLACED!
Tried two different airbox configurations
Tried to adjust the valves, they were within spec
Checked timing, it's good
Checked compression, 151 PSI
Tons of gas flowing to the carb
Tons of vacuum
Changed CDI
Changed coil
Changed battery
Changed magneto stator
Changed voltage regulator


I am DONE with this bike. About to put it in the TRASH

[tvnacman]

pull the intake manifold and carb, dribble a little gas while cranking. See if it will stumble or start.

John

[trashtruck12172]

after installing the bbk, did you up jet? you state that there is plenty of gas to the carb, but is it all reaching the motor?

[Alleyoop]

No, not a lemon, it went south due to the way it was treated.

To me the motor is getting to much gas IF it will try to start with OPENING the throttle. Opening the throttle starting that is allowing more air to come and it has a chance to get enough air for the amount of fuel to fire.
Check the vacuum hoses and check for gas in he vacuum hoses. Also close the fuel ration mixture screw clockwise then turn it out 2 turns.

The motor is being flooded if you have spark and compression. Also check the oil I am sure the oil is now fuel of gas.
Alleyoop

[cyborg]

You didn't follow the break in procedures,,you basically burnt up the mill,,,I my meager observations with the gy6 based engine I've come to the conclusion that the main problem with the design is oiling,,or lack there of,,,these engines are designed for urban transport,,,low throttle settings and very little stress,,,used in this way they can last a very long time,,,as shown by the large number of members on this and other forum boards with decent high miles racked up,,BUT this design inadequacy is the exact reason why scooters ( gy6 based) and small displacement cycles never hit it off in this country,,,long high speed running,,,and it's also the reason why you don't see any ( as in zero) entries in the cannonball scooter rally,,,they simply are not up to the task,,, the Taiwan gy6 ( basically a complete redesign loosely resembling the original design,,,kinda like the difference between Rosie Odonal and Scarlet johanson,,,they're both women but that's where the similarities end),,,based designs are mucho much better with real great oiling with filtration and balancing of rotating and reciprocal masses,,,huge differences in material qualities,,,ect,,ect,,,blah blah blah,,,I get the whole tinkering with the machine thing,,,but there are limits to the Chinese scoots,,,as in everything,,,

[mike932]

Apr 17, 2016 13:03:02 GMT -6 cyborg said:

,,,kinda like the difference between Rosie Odonal and Scarlet johanson,,,they're both women but that's where the similarities end),,,

Freaking hilarious, cyborg

[jct842]

Kind of what did you expect? No break in, no pdi.

[czmdiver]

Actually I find this refreshing.
Proof you have to Work Really Hard to Scuff a Piston on a GY-6.
There was some effort put into that.
Probably break-in oil?
They run in a Bath of Oil, Very Very Forgiving engine, seem to be able to go so lean it won't start let alone scuff a piston. 
I'm No Fan of a Light Weight break in but jeez.