MOPED ARMY

Looks like a really solid build list. I'd go with the performance pipe over stock style as a well built exhaust pipe is kinda like a supercharger on a 2 stroke. I think the Sha 15.15 may not be that impressive for a 70cc kit. I'd go mlm intake, shim, and this PHBG 17 it's incredibly tunable and will give much better flow.

I'd go with a Dellorto SHA style 15.15 carb and the mlm intake adapter. Treatland is out of stock right now but ask them when they expect more. The stock 12mm Express carb is a real bottleneck. I got 3 mph just by changing the carb to the SHA 15.15 on an otherwise stock express.

Your stock air filter fits nothing but the stock carb.

If I recall correctly, your main jet will be about 67 (+ or - 2) in the SHA with stock set up.

I think the MLM next level pipe would be a good choice and should net you a few more. Your main jet will probably be closer to 70 (+ or - 2) with that pipe.

That should get you close to your 35 goal and give you some tuning experience. You can take that experience and apply it to tuning a bigger cylinder if you choose to proceed. (edited)

Jack, thanks for all the info. I think I will try that carb and intake. Seems pretty straight forward. Considering running a cone to replace the air filter. K&N looks pretty sturdy, and that's what I've always used in my cars... I think you're right on doing carb and exhaust first, and worrying about a new kit later on.

Sorry to spam my own thread here, but while I'm at it I have a question about the rear brake on these. When I picked it up the kid told me he replaced it with a non OEM brake cable, and it's missing the nut on the cable to start it with pulling the rear brake.

Before I buy a new one off ebay, I was wondering if anyone had a quick fix on rigging that up to work?

You might consider using a cross clip clamp :

Link

-UPDATE-

I purchased most of the parts listed (minus the new kit) and a few extra goodies to get The Express going fast. While the parts went on with relative ease, I am struggling now with tuning my carb and getting it running properly.

Carb

I decided to go with the mentioned Dellorto SHA 15.5 Carb. This part went it pretty easy. I was able to use my existing throttle cable in it, and got the lever choke to function properly with the throttle pulled all the way. I used the MLM Lil Shorty intake with the suggested shim and it was a piece of cake. Carb came with a shim in it that was a pain to take out however.

Pulled the 68 main jet that was inside and replaced with a 72.

Air Filter

I went with this universal air filter from treatland. Seemed nice, fit snug, and mounted on easily.

Exhaust

Before replacing the existing carb, I installed the MLM Next Level Pipe and took it for a quick spin. Sounds nice, went on easily, and provided some good power on the lower revs. Still no real addition to the top speed however, but I did little in the way of tuning, as I was replacing the carb the same day.

I did have to remove the rear fender, as the new exhaust had no way of mounting to it, even though they provided a bracket that seemingly goes to nothing...

Oil Injector

From a quick read on the forums I read that with performance upgrades, deleting the existing oil pump and pre-mixing was the way to go. So I bought a variety pack of vacuum seals at the store, drained the oil, and plugged up the pump. Might turn the existing oil tank as an auxiliary gas tank further down the road.

Odds and Ends

-Pulled out the ratty fuel line that was on and replaced it with a fancy yellow line.

-Purchased a new rear brake cable and fed it through. Still not sure if I have it on right as it still won't start when pulling the brake.

-More parts in the mail, brake pads, battery, signal relay, etc.

Questions

After a long day in the garage, and successfully passing the written portion of my Motorcycle License Test (required in my state) I still don't have this scooter running properly! I was hoping y'all could be of assistance.

-Do I need to go with a higher main jet? I know it's hard to tell because everyone is different. But I have a variety pack of jets in the 70's range, around where should I be?

-With tuning this carb, am I just adjusting the air mixture? Is the fuel adjustment the flathead where my fuel line goes into?

-What is with this brake cable starting mechanism? I can only get it to start when I pull the brake and push it with a screwdriver.

-Why will my bike only start when giving it full throttle? Is there an adjustment I'm missing?

Below are photos of the whole setup, and a video of me starting the bike so you can understand what is going on. Hopefully one day this thread and all these questions can help someone else. Thank you in advance!

having to hold the throttle wide open to start it means it's too rich. Check your float level, the air mix screw (or fuel mix screw depending on the carb) be aware, those tires they are dry rotted really bad.

Finally figured out this brake lever starting mechanism! The two nuts confused me, however I found that the second one is just a locking nut, and you have to have both on the back, and tweak them from there.

Still on the hunt for my jetting issue. Will the proper jets really affect it by that much? I mean with each jet I try I notice very little gain, if any at all. I did a plug chop and it came out pretty dark, so I've been downjetting from 79 to 72. (All the jets I currently have.) I'm still not running as fast as I was at stock...