70cc kit, do i need to upgrade my crank too ?

You don't need a 21mm mate, 17.5 will be more than enough.

As for the thermostat, I don't even run one, but I think a normal one will fit it

 

iv read that a 21mm is the best carb to use to get the best gains out of a 70cc kit?

Or what about a 19mm carb?

well i went up the road on the bike today as it was sunny and i had nothing to do... i got up the road and round the corner etc... and it smelled a bit like it was overheating... and then it died.. i assumed a thermostat would sort that out.......

-kinda off topic this but,

any ideas why it might have died mate ? got coolant, radiators fine, no thermostat

 

Hey, ive just got my scooter back todday and was doing exact same and the carb isnt putting enough petrol through so you need to alter the float level

 

the bike does restart after about 2mins and rides as good.....

another thing! when it started to die on me once... i pushed the choke in and it was back to normal and rode fine and fast,...then it tried to die, so i let go of the choke and it rode fine again

 

dude please, the 21mm is the best for set ups like this... if you tune a scooter you should tune it right and make it to put out the best power as possible... so whats the point of putting a shitty 17.5 carb??? no point...

 

Maybe it will give you another 0.5 hp, for a fairly high price.

 

21mm on a cast iron is just a waste of petrol.

 

Thankyou very much

 

19mm be ok tho ?

 

if you've tried them back to back you may want to change your opinion.. the 70 kit NEEDS more fuel than the 17mm can readily supply

 

19mm should be fine mate

 

I have. There's a difference obviously but the fuel use vs performance gain isn't a worthwhile trade IMO. Bigger than 17mm fair enough but if you ask me 21mm on a cast iron kit is excessive...Horses for courses and all that tho

 

well would ideally wanna be hitting 60mph so would a 19mm carb be better than a 21mm one for that ?

 

17.5mm carb is fine dont need 21mm just going to waste more fuel. Even polini recommends 19mm for there big evolution 70

 

im talking about aluminium kits people sorry haha some other dudes once told me to put a 28mm carb on a malossi alu kit and i tried it and it was maaaaaaaaad cant imagine...

 

right so ive got a speedfight 2 50cc and wanting to do it up.. and first think im gunna do is buy an exhaust.. do i need to buy owt else to it works or can i just bolt it on? lol

 

If you make a seperate thread you will get alot more answers mate.

But for a pipe you will need a larger main jet and lighter rollers, as well as uprated clutch springs but theyre not vital.

 

cheers