Freeing up intake, what is necessary?

[chcknugget]

Hello,
My Geely scooter is highly restricted on the intake side. I can hear the engine trying to suck air through the overly-complex ductwork at nearly every rpm range. The scooter actually bogs down under hard acceleration because it doesn't flow well.

I took off the pre-filter air tube and my scooter ran funny, the idle seemed to be off. (maybe I just need to play with the idle mixture)

I plan on adding a little 1.5" aluminum tube with a little cone filter attached directly to the carburetor

Do you think my carb will need rejetting? I don't want to run lean, but if anyone else has freed their intake up I would like some advice and tips. I know these things are sensitive to any little changes.

[chcknugget]

O yes, it a is a 50cc 4-stroke scooter. I'll try to post a a pic of the motor if I can.

[aeholton]

You will definitely need to re-jet. You don't want to run too lean. You can overheat very easily. I've seen holes burned in the top of pistons due to people putting free breathing air filters and open exhaust systems on without re-jetting.

[chcknugget]

I'm not experienced with these kinds of carburetors, is this something a motorcycle shop should do? I've seen a couple how-to's, but maybe the ones I've seen are too complex. It seems like you simply bore out the main jet hole and adjust a spacer or something?

I assume you do plug chops to determine the fuel mixture. Any good tips or resources I should know of?

[aeholton]

Not sure who manufactures the carb for the Geely scooters. You would be better off buying pre-drilled larger jets. At least that way you can always go back to stock.

You may want to try a finding a local small engine (lawn mower) repair shop. They could probably do it for you cheaper than a motorcycle shop.

If you decide to bore out your jets...be careful. You need a nice clean hole. Use a good sharp bit if you decide to do it on your own. Also, make too big a jump in diameter...you can always drill it out bigger...you can't add back.

[chcknugget]

Thanks for the reply!

As far as I can see it looks like jets are basically long pins with little holes in them. I would rather buy a new jet and try that than possibly ruin a perfectly good jet should I want to return to stock.

Where might I find larger jets for a reasonable price? Maybe I'll check out some small engine shops and see if they can hook me up with a carb catalog or something... Any insight would be great!