New carb on my express, no low end anymore.

I have a 50cc express 2speed, with a jammy exhaust, and this carb. https://www.mopedarmy.com/forums/read.php?7,2876379

I jetted it for good mix and top speed, but now I have absolutely no low end power. Can/should I change the idle jet or something else in the carb? Or would it be something else on the bike?

Re: New carb on my express, no low end anymore.

you need to kit it and/or lighten your clutch shoes. or get a better low end pipe like a proma.

Re: New carb on my express, no low end anymore.

- Summerai - Corey Livieri /

Word.

Re: New carb on my express, no low end anymore.

How do I lighten my clutch shoes? What does that achieve?

Anyone have a link on how to check points on an express? Read somewhere that can be a big problem on these.

Re: New carb on my express, no low end anymore.

Zeke Rigg /

tune your carb you are lean on the bottom end. i recomend checking for casting flaws that could cause this. my cheap carb had a mixture screw with the tip missing.

o yeah also check for an air leak. (edited)

Re: New carb on my express, no low end anymore.

Where should I look for flaws that would hinder the performance? So, richen the idle screw and maybe drop the needle a bit?

Re: New carb on my express, no low end anymore.

Would the performance reed kit help low end at all? In all reality I'm just going to kit it this summer, but until then I'd like a little extra help at the stoplights. lol

Re: New carb on my express, no low end anymore.

Use hi-comp head.

Mill or sand yours.

Re: New carb on my express, no low end anymore.

Was there a head that was interchangeable on the nc50? like the spree head or something? Or what hi-comp head could I get?

Re: New carb on my express, no low end anymore.

Scott Schmidt /

dont do the spree head! it will run fine for a month and then youll need to kit it. becuase youll seize it.

Re: New carb on my express, no low end anymore.

mill head to the fins and lighten your clutch shoes.....pics attached

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Re: New carb on my express, no low end anymore.

wiki head milling. I used the draw file method.

Re: New carb on my express, no low end anymore.

Would it be a bad idea to just put it ON a real mill and shave it down that way? To abrupt? lol

Also, do you have a link on how to do the clutch shoes? Not sure how much to take off, or how to make sure it's the same amount on each side.

Re: New carb on my express, no low end anymore.

drill holes in each clutch arm , weight is measured with a scale . they should be equil . put the same size hole in the same place on both . 9/16 is a start .

Re: New carb on my express, no low end anymore.

Yo, Dan.

I am a big fan of trying the simple fixes first. You just increased the air flow through your system with that new exhaust. Can you change out the jets on that new carb of yours? Adjust the needle? I would consider trying larger jets (pilot and main) and adjusting the needle clip for your bike to run richer. Both are cheep and easy. Nothing to lose, right? You're about at sea level where you live, so you will need to set stuff richer than someone like me who lives at 4,500 feet.

Re: New carb on my express, no low end anymore.

Thanks for the helpful reply...

Well I do believe I have the right main jet, could go a couple sizes smaller I bet, but I can't seem to find a source for the pilot jet, I have no idea what kind it uses.

I put the needle clip all the way up and that help with the midrange, but not the low as much. Also have no idea what kind of needle it uses. Could just file it down I suppose.

Re: New carb on my express, no low end anymore.

check if you are rich or lean at low speed by slightly choking the carb while running. If it gets better when you do, you're lean, worse, you're rich

Re: New carb on my express, no low end anymore.

While idling? or running it on the stand or road...

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