Applying brakes, kills spark to plug

[HabHazard]

Hey guys, back again with another brain twister i've been working on now for a week or so. I have a cobra top boy, 2003 i believe.
First, this scoot has burned up 2 new batteries in the last 6 mos. or so, it doesn't take that long, but that's what i've been able to afford for batteries. The last battery I put in it was about a month ago, it is now down to reading 5volts.
Second, when applying the breaks to start, the scooter will not start. When I release the brakes, it starts.
I took the plug out, layed it on the frame, kicked the bike over with the brake on, no spark. When I release the brake I have spark at the plug.
I'm thinking voltage regulator, but any ideas would be most appreciated, my brain is fried atm, so I need some new perspective.
Also a quick, but dumb question. What does gy6 and 40qmb refer to? I see this all over the web when checking out parts, but have no idea how it applys to scooters.....

Thank you for your time guys.  

[marioG]

- voltage regulator
- or alternator


again:

http://www.kymcoparts123.com/pages/OemParts?aribrand=KYM#/Kymco_USA/Cobra_Cross_50/Wiring_Harness_%2f%2f_Electrical_Components/2K01140005/01140065

[HabHazard]

Got it, Thank you Mario.

[juice]

40qmb is the generic 2-stroke 50cc motor , gy6 is the generic 4 stroke . If you would like more info just try googleing "40qmb" or "gy6" . Good luck .

[HabHazard]

Ah, Ok Juice, that clears up alot, all the qmb and gy6 stuff was confusing the hell outta me, didnt realize it was that simple. tyty man

[Scooter Joe]

Your battery is not being charged, when the battery voltage is low then the electronic ignition module will not work and you will not get a spark for the plugs. When you apply the brakes the brake light lowers the voltage (about 3 volts) this is enough drop in the battery voltage  so that it is below the level that the ignition module needs to function. You should invest in a digital multimeter ($10) so that you can read the battery voltage.
Sears on sale and Harbour Freight are good sources.

[HabHazard]

Sorry I didn't mention this before, but I did measure the voltage at the battery terminals. I'm getting 16vdc which seems a little high..... this scoot burns batteries up like no ones buisness, but I have been buying walmart batteries... they may last a month at the most. I don't know if they are getting overcharged or what, but within a month they are down to reading 4 to 6 volts. So for the last 3 months or so I've been running without a battery, just kick n go..... I really don't know what else to do

[roboscoot]

i think scooter joe has got it......i would check the alternator....