So...i bought a non running scoot (piaggio NRG) that had been abused, stripped and needed a new top end. Needed a new exhaust at the same time so have fitted a technigas Q-tre, this has the restrictor still in. Iv fitted the new top end (50cc 101 octane) and managed to start her, little fettling of the carb and i can get her to idle for a little while albeit very lumpy. Dont know what top end it had before but it came with a fubar'd cast 50cc cylinder, and a very rough looking leoVince exhaust. And thus here is my dilemma, the carb on there is a PHVA 12mm carb, with the little knowledge i have of its previous setup do i try and rejet the carb to get her running right, or........do i just bite the bullet and get a 17.5mm carb and work from there? Plan in the (not so) long run, will be to move up too a 70cc sport kit and remove the restrictor from the pipe. the 50cc kit was just a cheap nasty one that wouldnt break the bank in 'just getting her running'. So im leaning towards just picking up a new 17.5mm carb. Any opinions??
17.5mm carb rejet but grab a selection of mainjets becasue when you 70 kit it your gonna be rejeting even higher. while at it, knock that restriction cone from the sports pipe so its a ready bolt on to the 70cc.
As above 17.5mm carb Cone out the pipe Open sponge filter in the original box Re-jet ENJOY p.s. hope you didn't buy the chrome version, it'll start to rust in 3 months.....................
Update, i knocked the cone out and it ran better at idle, not so lumpy any more, still only ran for about 5 mins and then died. Tonight i took the carb off and gave it a good clean, turns out it is a 17.5 and not a 12 so that solves that decision, think the main jet of 70 is prime culprit for bogging at WOT. not sure why it has a 70 in it as all the 17.5 carbs i seen come with a min of 80 when new? Also found the cause of the running for 5 minutes and then dying, seems i had a small split in the vacuum pipe and thus had a vacuum leak that was resulting in the fuel not being pulled into the carb fast enough. So jobs a guddun, just need to pick up some jets, any recommendations of what size to start with, would 80 be too ambitious? only ask as i was going pick up the polini 80-98 jet kit And Steve, no i didnt get the chrome one, i think chrome looks hideous. i went for the bare metal one and gave it a coat of white VHT engine paint. scoots going to get a change in colour scheme to black and white (to match my other bike and biking gear) once its all running nice.
