Lifan 50QT issue, need help.

[davandsarah]

Picked up a Lifan 50QT that has been sitting awhile, cleaned gas tank, carb, installed new plug and charged battery. In my rush I installed battery cables backwards. The fuse did not blow but now I have nothing when I turn on key, no lights power etc? Found a wire with a plastic end with 2 prongs coming off negative cable but this isn't connected and I see nothing to connect it to. Daughter getting license soon and hoping to surprise her, any help greatly appreciated.

[tortoise2]

Jun 9, 2019 10:29:47 GMT -5 davandsarah said:

Lifan 50QT

If LF50QT-2A, appears to be typical 139QMB engine . . but unclear if AC or DC-CDI ignition system?

[davandsarah]

I'm going to pick up a new battery to rule that out, but I hooked a boost pack up directly to the cables with battery out, pack read 12.8 volts and I still had nothing happen when key was turned on. I verified with previous owner that everything worked when last ran ( lights, electric start etc.).

[davandsarah]

Also, I jumped solenoid with screwdriver and motor turns over but doesn't start, still nothing powered up with key on like lights or instruments

[davandsarah]

Just cleaned all plug in connectors with electrical spray cleaner, took apart ignition switch and cleaned that as well, nothing happens when I turn on key, out of ideas now

[pinkscoot]

Possibly your kill switch? Not familiar with Chinese kill switches but on Italian scoots the starter won't do anything.

[FrankenMech]

Depending on the scoot you could have blown many things when you connected the battery backwards. You will just have to go through and test everything one piece at a time. Good luck.

[davandsarah]

I'm far more mechanical than electrical. I don't know what to start with for testing, I have nothing when I turn key on, so some of the electronic items are only necessary for spark, starting etc. When I turn the key on I don't have any power to anything like horn etc.

[GrumpyUnk]

Connecting with the leads reversed likely hit a few things. The first I would look at would be the regulator/rectifier. It is connected to 1)ground=green, 2)battery=red, 3)alternator/stator=yellow&white.
I suspect the rectifier and regulator may be cooked. Disconnect that, and you'll not have Yellow or white to the cluster, gauges, or lights.
I would check for spark. You should be able to kick the engine over using the kick start. Remove the spark plug, put it back into the wire, lay it on the engine. Kick, key turned to ON, kill switch in RUN. Should have spark. No spark, either the CDI is cooked(it does not see 12V from the battery if an AC unit), or the coil cooked, or the ground(kill) switches are still grounded.
This bike may have a starter inhibit or spark inhibit if the side stand is down. The fancier models had a protection so you could not electric start nor have the engine run while on the kick stand. The center stand does not have that feature, to my knowledge.
The only things you might see with key ON, engine OFF, are the fuel gauge, rear tail light, front 'park' light, and some turn on the instrument cluster lights. Some do almost nothing.
If the brake light works when the key is ON, you should see 12V on one of the small starter relay terminals(actually both). The ground to operate the relay would be provided by the start button, as limited by the emergency STOP button immediately above the start button. Said emergency button kills the ignition as the same time it disables the starter relay.
When cranking, do the check for spark, and if no spark, you can use a meter to check the other signals that are supposed to come from the flywheel/stator. 1) AC to operate the CDI, 2)trigger for the CDI to fire, 3)yellow raw current, 4)white raw current. A meter up in the general right side rear(under the plastics) at the connector coming from the alternator would be a place to check. The two CDI wires are generally separate from the stator connector. You can follow the wires up from the top area of the flywheel to up near the relay and coil and enrichment connector.
To continue on the relay, if you have 12V at the small terminal, grounding the other small terminal should make the relay close, and send power to the starter motor. The relay is generally not 'polarity' sensitive.
I have one that did exactly the same. Nothing with key on. No start. Found a bad connection at the relay connector after tracing ground and B+ for hours. Re-bent the connector, and the starter kicked. Got it running, and no headlight, no tail, no brake light. Bulbs for one, and more loose connections.
They yellow from the stator was / is intermittent, and when it connects, the headlight and tail light, along with cluster lights all come on.... So ONE wire can mess things up.
If you get it started, check for ~28v on the white & yellow(not smooth AC, but bumpy DC I think) at the stator connector and at the rectifier regulator.
But first, you need brake light action with the key ON, and ground from the starter button. Then sparkage, then fuel... then fix all the rest which may come clear while kicking bay../ TelCo joke/

tom

[SMALL CC TEK]

Jun 9, 2019 10:29:47 GMT -5 davandsarah said:

Picked up a Lifan 50QT that has been sitting awhile, cleaned gas tank, carb, installed new plug and charged battery. In my rush I installed battery cables backwards. The fuse did not blow but now I have nothing when I turn on key, no lights power etc? Found a wire with a plastic end with 2 prongs coming off negative cable but this isn't connected and I see nothing to connect it to. Daughter getting license soon and hoping to surprise her, any help greatly appreciated.

 Bro Don't feel bad i did the same thing on a Sold scooter i was getting ready for sale ! lol   Serious business and it was the only color they liked !   I got lucky and noticed it  in about 40 seconds ... Check that small thin red wire for continuity peel back the tape and look at it  good see if it fried you might get lucky like i did !