here's how I'd build out a decent set on the cheap
1/4" flex head ratchet. if you're going to make one vanity purchase make it the snap on TF72. yes, that is a $138 ratchet. trust me, you will use it more than any other tool in the box. not only is it absolutely a top ten desert island ratchet, it's number one with a bullet. or pick up the icon pro one from harbor freight for $35. either way you need a flex head 1/4" ratchet.
1/4" other bits:
>you'll need extensions. I like the "wobble" style ones that are dual function where you can seat the socket down further and it becomes fixed as well. bonus if they have a knurl on the shaft. there's sets on amazon that have all three drive sizes, I bought one from vector (00249V) and it'd be about all you would need, but really any decent set will do ya.
>you'll need a 1/4" u-joint. this, with the wobble extension will allow you to get to anything. especially the exhaust header nuts. buy two.
>HF's Pittsburg pro color coded short and deep 6-point sockets are fine. if you want to pop the loot or don't like the color coded ones, grab the icon's instead. they're more money than the chrome Pitts, but they won't flake off.
3/8" ratchet, get a fixed head and a flex head with a long handle. HF icon professional is more than adequate here.
>short well, you want 12pt sockets and deep you want 6pt. again, you can go low rent HF Pittsburg pro chrome ones or color coded.
>allen sockets. you won't need torx on a GT unless somebody replaced a grip of screws. I've had fantastic luck with craftsman, they seem to be about the only thing they still make worth a shit.
1/2" drive, same same. HF and grab some shallow 6pt sockets. you *really* only need a 22 and a 24, but the rest are nice to have.
scewdrivers, buy a set. the Quinn set at HF is cheap and decent.
>you'll need one each of a super duper long Phillips and thin shouldered flat blade. if they're not in the kit, you can buy separate.
>add in one or two BFS that you can buy loosie. you never know when you need a persuader or a pry bar or a punch.
wrenches, again. just grab a set from HF. icon or Pitts pro, standard combination.
>add to that one each of a ratcheting flex box end 8, 10, 12, 13 & 14
pliers, get a set that has: needle nose, slip joint standard, diagonal cutters, and slip joint channel locks.
>add a set of the little mini pliers from HF
>add in a pair of duck bill (aka flat nose)
>add in some vice grips of different sizes, get the 3-pack set.
>you'll need snap rings pliers, so just buy a cheap pair of reversible with interchangeable heads
>spend the money on some cobras.
this is a smoking deal. like the snap-on ratchet you will find yourself using these ALL the time. you'll come to wonder how you lived with out them. you may even name your child after them, and if you think about it "cobra" is a pretty bad ass middle name for a girl.
misc other hand tools:
>T-handle allen keys. buy a set from somebody decent, park tool, craftsman, etc.
>T-handle 8mm fixed or a 1/4" drive T is super nice. motion pro makes nice stuff.
>hammers: regular sized ball peen, a 2-ish lb brass, combo plastic/hard rubber unit, a 3lb or so dead blow
>if you plan on doing your own tires, you'll need tire spoons and rim protectors.
speciality things and stuffs:
>feeler gauges for setting valve lash. I have
these from lang and they're awesome
>you'll need a clutch holder and front pulley holder for the transmission service. scooter parts co has you covered there:
https://scooterpartsco.com/tools-c-22/
>get a decent digital multi function multi meter and a test light
>mighty vac if you are working solo and need to bleed brakes.
>you absolutely need a stubby 15/16 or 24mm wrench to get at the oil sump plug. I like the craftsman 44102 you can pick them up on ebay pretty cheap. or just buy a standard wrench and cut it down.
>you'll need some punches, just get the HF set
highly recommended:
>electric impact. unless you have air. then get yourself a full complement of 1/4, 3/8's and 1/2 air guns.
>center jack
>socket organizing racks
highly highly recommended if budget and space allows:
>motorcycle lift.
there's a bunch of other specialty stuff that you may need down the line. but that's more of let's cross that bridge when we get there.
I'm sure there's more that I'm forgetting because I'm not staring at my tool box right this second.
anyway, these are my recs. people love to crap on harbor freight, but their hand tools aren't terrible so long as you stay with Pittsburg pro and the new icon stuff is about on par with kobalt and older craftsman.
tools are also a deeply subjective thing. what wrench feels good in my hand you might not like the finish or the balance of. some people buy on name only. every ratchet has different action, choose the one you like.