Guys this is driving me crazy. I replaced Bertha's old engine with a brand new 125cc. At the time of the first start up there was no battery so I used the kick start to crank up. The engine works beautiful and rode about 1 mile just to test. Yesterday I bought a new battery (a little bigger) and installed it.

The engine cranks nice but not start. After several tries, I decided to use the kick start and Viola!, the motor starts up. Since this is my daughter's bike, I want the starter system in working order because she can't use the kick.

After various measurements I found that there's no voltage coming to the input of the coil at the moment of crank up with the starter. If I use the kick then I got voltage at the input of the coil.

I think that if the CDI is not working, it will not start even with the kick. Anyways I replaced the CDI with same results (start up with kick but not start using the starter).

Any help will be appreciate.

 

Might be wrong,but if the battery isn't up to snuff or sometimes even if it is,starter may not be turning it over fast enough to get enough spark to crank. As the kick starter puts direct force on the engine and usually more torque,could be why it cranks right up.Had weak battery Polaris youth models do basically the same thing.

 

how many volts is the battery showing while cranking? how many volts are down at the solenoid and starter area? i concur with OPT on this. time to measure voltage. it may not be "fast" enough.

 

did you give the battery a initial charge? may not be up to full voltage

 

Had that happen on my 500. Turned out to be a dirty trigger/Pulse coil next to the flywheel but since your motor in new I guess that can't be it.

 

i don't know TLC, i've seen surface rust show up fairly quickly. but it's so dry where i'm located, when it is finally humid, BAM, it showed up on the china quads i've worked on.....for some odd reason