Piaggio zip 50 2 stroke 75 main jet???

Basically I've been told 75 is too high because my bike doesn't go past 45 it has
Tt exhaust
Malossi multi var variator
3G clutch
5.5 rollers
75 main jet
Does it need a lower jet?

 

whats the plug colour like, zip that sparkie out and have a gander at its colouring you want a nice chocolate brown if thats the case the 75 jet is fine and it could more so be a needle setting problem ( either slide needle is to lean on mid range or a little to rich at midrange )

if sparkie colour is black the 75 jet is a little to much and its running some what overly rich try dropping down to around a 72 jet and see how it goes ( but keep and eye on temps and plug colouring dont be running lean , you wanna air on the side of a little rich is good )

 

Thanks mate I'll keep it at 75 An drop the needle An see if it goes like fuck

 

It was on the middle needle mate and the spark plug was white so do i need to go higher for some reason?

 

Hi, did you sort this problem? I can't work out how to make my own forum, sorry. My zip is all standard except technigas exhaust. The bike was fine before I put the technigas exhaust on, it now loses power at near half throttle, I think this is jetting. Anyone know what jet it should have in it? Thanks

 

Hi, i'd put a 65 jet in and work down untill your spark plug looks milk chocolate brown and doesn't bog down, if you do not upjet soon it will be running too lean.

 

Cheers I ordered 50-72 jets

 

I don’t know how to make my own formun, I’ve currently just upjetted my carb to 74 jet on Yamaha aerox and it was running fine and then it all off a sudden started bogging, let it cool down and was running fine until it got warm again any ideas on what it could be?

 

I have a 76 jet and can ride for 10 mins and then I get the exact same problem.

 

Any idea what it could be mate?

 

Rich1357 : Ashley

putting on exhausts requires an upjet in the carb , its not a put this size in and all will be handy dandy , all scooters will be different due to area they are in the weather and likes all these factors impact the jetting at that time.

as for piaggio jetting i upleaded a huge amount of info on piaggio scoots and it includes when possible the stock jet size and the stock needle setting so well worth looking at for your zips. a rule of thumb we upjet by 10% - 15% ( so a 56 would be a 65 or more even upto a 70-75 at a 15% jetting rate ) start at the 15% jet rate then come down a size or two . link to forum post on piaggio schematics : https://www.scootershack.co.uk/threads/piaggio-scooters-wire-schematics.38206/
also has jetting info and carbs info


testing you MUST test each jet , these are NOT upgrades they are fine tuning the scooters motor to the correct amount of fuel to air mixing, you must put a jet in and try it , do not expect your scooter to run perfect the first time, it 9-10 times will run like a sick dog , choking, coughing , splurging and the likes, each scooter is different each one will want its own jet size , each exhaust is very slightly different so they to will require the jetting to match the exhaust . its a skill you learn over time so you must test each jet to see the reaction the scooter gives.

There is a sweet spot, its when you have a pull away with a nice crisp mid range and a nice top end , throttle transition should be smooth through this range, no surging , no stuttering - bogging - no holding back then going like the clappers. it should when the power band kick in be a rapid raise in rpm to the end no hold back like a pause then a wham the powers there.

IF YOUR NOT UPTO THE JOB do not carry on , if you do not jet correctly and the scoot runs to lean you will damage the cylinder - piston - rings or even start to damage the crank and bearing due to the heat produced when running to lean , a local motorbike shop should charge you a couple hours labour and the cost of a jet , they will jet your scoot so it runs correctly , you will need to tell them your having overheat problems due to wrong jet size and you require an up-jet .