Upjetted and now a problem

[silverspar1]

I have to admit, I don't think I know what the hell I'm doing but I'm gonna figure this scoot out if it kills me. Basically I'm trying to tune my scooter to its fullest potential while leaving it at 50cc.

So I finally get my factory derestricted header pipe. It works good, gets me to a comfortable cruising speed of 36 mph, downhill about 45. It's quiet and works at its best with 10g weights. Well I also found a Tecnigas Next R chrome exhaust on Craigslist for 40 bucks. I took it to a fab shop and for 20 more dollars I had it modified to fit my scoot. This thing is a beast. It won't work well at all with 10g weights but I put the equivalent of 6gs( Three 12g weights) and it will go. Cruises comfortably at 42 mph and tops out at 52 mph downhill. Also great takeoff and stays solid at 38 mph up the steepest hill around where I live.

So I have it like I want other than I think 7g weights would be perfect and they are on there way. I was told buy a guy who used to derestrict Daelim scooters that I needed to up jet from my stock 75 to 80.

I thought well that's the last step, so last night I took my carb off , took out the main jet and did it. This morning I fired it up, took a ride and everything was basically still the same, but when I reached 38 mph it bogged down and would'nt go any faster. I need some advice on how to tune this thing back to where it was or better if possible. I guess I could buy another 75 jet but I'd really like to try and improve on what I had before if I can.
Anyone have any ideas on how I can solve the bogging down at high end issue???

[90GTVert]

I'd say you have 2 basic options...

1) Keep the 80 main jet and get a free-flowing air filter.

2)Put the 75 main jet back in.

You can't always assume that what works for one scoot will work for another when it comes to jetting. If everyhting is exactly the same and you live in the same place and ride the same way, sure. Otherwise you only use other's experience as a baseline IMO. For example, one person told me he used a 125 main jet in his Arreche 19mm carburetor on a 90cc just like mine. I ran on the rich side using a 75 main jet.

Adding a larger jet doesn't always mean more power. You need the proper jet, not the biggest. I'd have to think your bike is bogging because there's just too much fuel coming from the main jet. If you decide to try a better air filter you may wanna see if you can get a 77-78 main jet, as well as 82-83, and 85. I like to have plenty of jets around so I know I can get it in tune. If you are trying multiple jets, needles, clip postion, CVT components, etc... it's a good idea to keep some sort of log. Record the temperature, current setup, where it lacks, and where it excels.

[silverspar1]

That sounds like good advice. I ordered an air filter and some more jets earlier today.

[pedez2000]

i was going to say get a 77.5 or 78 jet i have them.but you probable already ordered that.fine tune the mixer too.do you have a racing coil and cdi in your bike if not i have some.

good luck bro.

[YellowScooter]

Also 10g roller weights are better suited for a150cc not a 2stroke 50cc, but I suppose you done figured that out already.
6g are close to what an unrestricted 50cc has out of the box. As you free up power and get the jetting right, you might wanna try a set of 6g sliders and next size stiffer contra spring (2500rpm?) to help the tranny downshift a bit better and get you uphills faster without sacrificing top end speed.