Help needed for 2009 50cc pegeout speed fight 2 LC R-cup

Hi people having a nightmare of a time with this thing.
Purchased for my lad 5 months ago and been running sweet no problems. Everything worked perfectly.
Now it's just started blowing fuses, it will not phisically start. As soon as you kick it BANG fuse blown. Use the Electric start, BANG fuse blown.
I can turn the ignition on and everything goes live, lights come on, indicators working, horn but as soon as I attempt to start it BANG fuse blown.

I have removed all the bikes plastic faring and stripped it right back even the black protective covering from the wiring harness/loom to check for a short. I've checked all connector blocks for loose connections etc.
After doing this 10 times over and being satisfied that the wiring was ok I decided to replace the stator and vaultage regulator as my friend had original new ones in his shed. The old ones may well have been fine i know, but they where free and and have ruled out any bad play there.

The fuse that was in the bike when we purchased it was a 20 amp but everywhere I've looked says it should be a 5amp or 7amp.
Has anyone on hear ever seen a 20amp fuse in a ped it sits between the battery and regulator.
I've been trying with a 5amp instead of a 20amp as I think that's way to high.

Any advise would be much appreciated
Thank you in advance.

Could it be a faulty Cdi unit or starter relay???

 

Hmmm.
I'm gonna get back to this later

 

Have you put a meter across the fuses terminals to see what current is drawn. Big difference between finding a 15 amp problem and a 200A problem.

 

Could be the starter relay or wiring to it, wiring behind the flywheel shorting as it spins round, you've obviously got a live going to earth when you either kick it or press the button, that would indicate that it happens when the engine starts to turn.
Something to try, disconnect the coil and see if it blows the fuse when you try and start it.

 

I thought it was the stator wiring too but if it's been changed I'm lost..

 

Cheers for your replys guys I've fixed it the new regulator/rectifyer that I fitted is Chinese and needed to be wired in upside down and back to front.

Crap thing is I've renewed just about every electrical component on the bike before realising.
Plus side is I have spares for everything.

 

Should be trouble free now huh?

 

Just when I thought everything was gonna be OK bike keeps bogging down when trying to get it moving so carb off tomorrow morning. I'll let you know if I can sort it out.