50cc or 75cc

[mwiggers]

Hi,

So I'm new to the whole scooter world. Just bought my first one in December as a Christmas present! It's not a very expensive or nice one, but its in good shape and it originally had a 2 stroke 50cc engine, but the previous owner had replaced it with a 75cc engine and it ran great!It would get up to 50 mph with me on it (I'm pretty small though

The only problem was the battery, it didn't seem to hold a charge for more than a few hours and had to be kick-started almost every time I wanted to ride it. So I saved up a little cash and had a mechanic come out to replace it. So then several hundred dollars and 2 days later this guy brings my scooter back and it starts right up every time now, but it only gets up to 35 mph??? I'm wondering if this guy took advantage of my naivety and replaced my bigger engine with a smaller one thinking I wouldn't know? How can I tell the difference between a 75 and 50 cc by looking at it?

Any help would be appreciated! Also if someone knows a better scooter mechanic in the Miami area that would be great!

[super9]

WELCOME

to check if its a 50cc or 75cc you would have to take the cylinder off to measure the bore but as you are new to the scooter seen im sure you wouldnt know how to do that...and it doess take some knowledge maybe one of the other members has got a better answer for you...

also go back and ask the mechanic what he done to your sccot as some do like to take an avantage of women

[millsc]

It only takes a few minutes to change the battery, he most likely took your parts

[prodigit]

If he did not take your parts, it could be that the scooter will perform better over time, as the battery gets charged up, and perhaps winds calm down etc..

[teddy554]

do what prodigit that got to be the dumbest thing i have every heard, yeah you can swap a battery in less then ten minutes as to why you scooter is slower its hard to tell but I am sure it has to do with your shady several hundreds dollar mechanic that took days to change your battery

[skuttadawg]

What could cost a few hundred dollars as a battery should be around 40 or so . Did you get a new stator and voltage regulator ? My 2T has sat for 2 months and still had plenty of charge in it . A trickle charger around 1/2 amps is not that much to keep it charged as severe cold weather can drain out the juice .

Does it feel like it has the same power and will it hit the same amount of RPMs as it did or at least sound like it if you do not have a tach . Most 49cc have a 40mm bore and the BBks can have 47mm or 47.6mm bore . Yeah it does not sound like much but wow it is on a 2T

Clean the airfilter , jets in the carb and a new spark plug can often do wonders . I use a NGKBRP8HiX iridium spark plug in my 2T

[savy09]

mwiggers,
Did you look on the outside of the engine block (by the CVT) for a stamped serial # of your scoot also stamped would say 139QMB (50cc)? That serial# should match your regi or title. Again you would have to check the cylinder size if it was tampered with.
Also, try twiking your carb air/fuel mix clockwise+gas=rich, counter+air=lean, and ride it. Then do a plug chop. Check oil & replace, same for gear oil, ck both for metal filings, you may still be breaking in the 75bbk.
ride safe--savy

[transitman]

next time you should do your own battery swap, theres not much to it. I would call that guy and ask him what up with the missing 15mph. a battery would not do that. you may have had nice dr pulley rollers or a performance clutch too. I wonder if he swaped that out with stock peices>?

[super9]

prodigit, battery lmao the battery has nothing to do with performance...sorry but what a dumb answer

[prodigit]

I guess I had divine inspiration!
Don't even know myself what I was meaning with it, but it all made sense when I wrote it...
lol