We bought our son a Tao Tao ATA125D in 09. It ran pretty good at first and in the past 2 years has been sluggish to start, if at all, cold or warm. It is on its 3rd battery and 2nd starter due to jumping it and trying to get it to turn over. After a year, I did get it running on a 10 amp charge, starter fluid & hope. Ran for a while but when shut off, it would barely turn over. I did replace the push button to the starter after a mechanic said it may be bad. Wasn't it. Its almost like there is too much compression or a wiring problem. Took plug out, no difference. Any advice would be greatly appreciated.

 

so it is "barely turning over/cranking" or struggling to fire up and long winded cranking?
1. make sure battery is charged up.
2. get voltmeter/ohm meter
3. measure voltage at starter when trying to crank/turn over engine. what's the voltage measure at the starter?
3. have a compression gauge? if so, what's the compression while cranking?
4. when running, does the quad run/idle ok? does it rev up ok?
report back.

 

Will do a compression test at a later date due too not having a tester. Although I did lie. Took spark plug out and it turned over like it was new. Put plug back in and the sluggish was back. Put a voltage meter on the starter selinoud and was getting between 8 and 10 volts with and without the plug. As for the idle, its fine after a brief warm up. Did turn it up just a bit .

 

you know, there have been some recent cases where guys that we've helped just put in a new NGK spark plug and BAM!!! problem solves. $3 fix. not saying that it will cure this one this time, but it couldn't hurt. i'm also beginning to wonder what the valve clearances are and if they need to be checked and adjusted. can you do that? do you know how? there's videos on youtube that show you.

 

I will try a new plug & go online to learn valve clearances. Thank you very much.