Slow cranking with good battery

Hi!

I have an issue with my YQ50 Aerox. When the engine is cold i sometimes have an issue that the starter cranks slow just like if the battery was dead, but the battery is good(charged and like 2 months old). If i keep cranking for around 20 seconds the starter might spin faster and start the engine or it might not, but i usually just use the kick. But the moped also always starts on the first kick.

The weird thing is that i don't always have this issue, i store the moped inside a garage which is around 15-20 Celsius and i never have cranking issues. But when it has been standing outside (usually around 2-15 degrees Celsius) i sometimes have the cranking issue. But if the engine is warm, it cranks as it should and starts within a second or so.

So i am wondering what the cause might be, if it is the starter itself that is going bad or perhaps something to do with the transmission?

Many thanks for any possible help!
/Tim

 

Nothing to do with the transmission, that's a completely separate unit that doesn't come into play until the engine is revved to a certain point.
Check the starter sprag clutch and the starter bendix and also the earth points to the engine and frame. Might also be worth putting a new starter relay on.

 

Okay, is the starter sprag clutch inside of the cluch assembly or is it somewhere else? Also, what do i look for when i am examining the starter sprag clutch and the starter bendix?

Many thanks!

 

Take the belt cover off. The sprag clutch is behind the variator, so that needs to come off, the starter bendix you will see mates in with the starter motor shaft where it passes through the engine case and turns the starter sprag

 

The starter is a common problem on these minerelli motors. It's normally the lead itself attached to the motor, it gets so much road dirt on it.
I've changed probably about 50 of them over the years.
Worth checking the sprag clutch as Steve says though

 

Alright! Thanks a lot for the help, i'll check the sprag clutch, starter bendix and the starter lead. If i have any issues i suppose i'll be writing another message here.