70cc jetting

[milly]

I may have already been here before but don't think so.
Naraku 70cc kit fitted with crank. I am using a 20mm carb for the first time. I put it on straight out the box but had running issues. Granddaughter was coming down so put a standard carb back on just to teach her to ride. Once back home Thursday I would like to put 20mm back on.
My question is what size main jet for starting off with would be best to try. Would also like to try retaining standard airbox and exhaust system ( non cat ) if possible. I do have access to cone filter and less restricted but noisier exhaust if needed.
Thankyou

[scooterted]

I started with a 94 on a similar 72cc setuo with a pd19j carb. Ran fine, maybe a little sluggish but didnt sputter. Maybe try a 98 to start?

[90GTVert]

95-100 is often a good starting point. To me, you don't plan to get it right on the first try anyway. Even if it feels great, I'm gonna try more jets to see what happens. Good news with the 4Ts is you don't have the big risk of soft seizing like the 2Ts.

[milly]

Thankyou both for that information

[greginisn]

I have a feeling that since both you and 90GTVert are fairly close to sea level but your temps are generally cooler you may be able to use a slightly bigger jet.

Good luck, Greg

[milly]

Jun 7, 2018 23:53:02 GMT -5 greginisn said:

I have a feeling that since both you and 90GTVert are fairly close to sea level but your temps are generally cooler you may be able to use a slightly bigger jet.

Good luck, Greg

Thankyou Greg yes only 600odd foot here highest rising to 1500 ft locally.

[scooterted]

Im curious about where you ended up with the 20mm carb as opposed to the stocker.

[milly]

Jun 9, 2018 8:50:02 GMT -5 scooterted said:

Im curious about where you ended up with the 20mm carb as opposed to the stocker.

It is sat on my work bench along with the manual choke set up Ryan ott sent me from the States waiting to be attached. This morning I changed my 125 lml to a 150. I am cutting back on time I spend on scooters at present but will update soon when I get bored and go back to them 😊.