Hello everyone, really glad i found this forum and i'm hoping someone can point me in the right direction testing the electrics on this quad bike.
The bike is a ATV STAR with a GY6 150CC (4 stroke) engine,i'm helping a friend who's quad it is, i'll give you what i know from it's history.
The quad use to run fine but it was going through batteries, you could run the quad for an hour then switch it off, after that it would'nt start unless you gave it a jump with some booster cables.
The quad has been stood for a few months and when we've came to start it, it would just spin over and not fire up.
The first thing we did was check for a spark at the plug, which we have, but for good measure we baught a new NGK plug just to rule out the cheap chinese plug, we still have a good spark but no start, not even a cough.
We've stripped and cleaned the carb twice which made no differance, plenty of fuel getting through to the plug.
I've checked and tested the auto choke and that's working.
We tried some easy start down the carb, got a small backfire pop but nothing else,we've tried several times still nothing.
I've checked the valve adjustment, all good.
The engine seems to have good compression on the thumb test and turning it over by hand.
The battery is fresh and a good brand, it's holding 13.5v and not draining if left overnight.
I did a visual check of the wiring and found a broken earth strap plus a bad battery earth, sorted those but still nothing. One thing i did spot when having a look at the regulator was one of it's pins was covered in blue/green mould, that was cleaned up but still nothing, we have since baught a new one but again no differance.
The inline battery fuse is good, no sign of any melting in the wiring loom, the brake light switch works for when you come to start the quad,the starter motor spins well and fast, i'm baffled.
From a brief test i carried out yesterday the quad has an AC stator, i'm not the best with a multi meter but learning fast lol
Any input would be a great help, before i reach for a box of matches and some petrol lol.

Dave

 

89 views and no reply, i guess like me your all stumped lol well i started looking further and decided to check the stator out, somebody has been there before and made a right muck up of things, it was left in a friends workshop i've since found out, and it looks like someone has been looking into the battery issue.....
They've managed to put the rotor on 180 degrees out!! i'm guessing they did'nt have a rotor puller looking at the screwdriver marks, they've damaged the stator as well.
Not going back there until early next week, will see how the stator checks out and go from there....

Dave