first, its a 139QMB not QMB139
ok i shut up.
yes its possible and mostly easy if you can use your hands. harder if you are a office worker type ( or you are like Rolling Bender and do both perfectly, but thats rare )
you are wasting your time 80% of the time.
i also did the swap beleiving the crap they spread.
yes it help alot, IF you put over abusive load on the electrical system after 3k rpm. like 10 halogen bulbs, heating gloves and boots, radio with 467890 speakers, and dual h4 halogen bulb. idle is still NOT charging at all, up to 2800 rpm ( depending no stator quality ).
in normal use, its a total waste of time. the stock 8 pole stator got enought juice to power everything DECENT you throw at it. its true the idle charging sucks, but even a 11 pole upgrade doesnt change anything there.
if you need ot over abuse the electrical system and is aware that idle charging wont change at all, here what you need.
11 pole stator.
6 or 7 wire regulator/rectifier ( 7 wire way harder to find ) ( 7th wire is white and used for auto-enricher and is unregulated DC up to 90v ).
yellow wires ( lenght according to scooter size and how good of a job you do ). or the proper wiring harness but $$$ ( mine was for a TANK scooter. dont ask i have no idea wtf is a Tank scooter ).
you keep rotor/flywheel if you had the 8 pole ( and i think you do ). if you had 7 pole crap, you need a non weirdo flywheel aka 8 pole.
7 pole is different, 8 and 11 pole flywheel are the same.
its true that it can charge better at idle with this upgrade.. but what they dont tell you is that you must crank your idle speed to 2800 or so, thats not idle anymore and way too much for absolutly no reason. not "bad" per say, just nosense.
of yeah you can put more load on the electrical system before the rpm drop ( at idle ) but you aint gaining anything else.
you're wasting your time doing this unless you want to over abuse with useless electric stuff.
better go the bright way ( sorry for the word game hehe ) and put LED everywhere instead of 1800' disgusting non secure outdated unreliable incandescent light bulbs.
some led are AC compatible, but its way better to run them DC on battery ( very very easy ). for the headlight nothing beats a separate on/off switch so when warming up or working on it while running you dont drain the battery. ( keep in mind in stock form, incandescent light bulbs on AC also put load on the stator, reducing the charging effectiveness ).
if you go this GOOD route, i cannot tell wire color because LIFE ( i had 3 identical car, none had the proper wire color according tos ervice manual... worse for bike like kawa and honda ) but a general guidance.
open the left controls on the handlebar and unplug AC wire ( you gotta find out... on 4 scooter they were different color ) and then run a wire from the black KEYED switch from ignition switch and plug it there instead. DONE. DC headlight. i suggest using a relay tho. do the same for front running light.
for the tail light its a but more complicated since there is both AC and DC. brake is on DC, running light is AC. all in a single bulb. so follow the AC wire of the running light on the tail light to the front. unplug this wire from whatever its connected to and plug it on the same black wire we talked previously.
voila the only AC still used is for auto enricher, so way less load. and if you went LED everywhere, you end up with a way better gains than upgrading to 11 pole, and its almost free. yeah you have to buy LEDs.... but you probably have to change those horrible incandescent light bulbs that are always burnt anyway. if your old bulbs were fine, then its still way cheaper than the upgrade and easier.
sorry my english is bad and the way i explain shits is even worse.