The Little GS125 Carb Issues

[GSXJosh]

I know they aren't a popular choice being a small cc bike but this nugget that I have needs some help to get back on the road.

It's a 1982 Suzuki Gs125es. Single cylinder bike runs a Mikuni slide carb, later models ran a Mikuni round? Carb.

I'll start this off with the bike has a cheap eBay pod filter. The original air box was not with the bike when I bought it.

I have rebuilt the carb with genuine parts. The carb was cleaned out, everything was spotless.

I've seen videos of these bikes running without air boxes. This one doesn't want to play nice.

It will start with choke, but when revved has a hanging idle, when choked with my hand or choked again with the choke on the carb the idle will come down. I have adjusted the fuel mixture to within an inch of its life, I have richened the slide needle to maximum but it still wants more fuel to run properly.

I believe that genuine parts even if old are still better than Chinese eBay carbs and I don't want to go down that route... Yet.

The bike is going to be a commuter bike so I need reliability in it. Are slide carbs known to have issues if not restricted correctly with a filter compared to a newer Mikuni carb? Have I got a worn out carb? Are they thongs or flip flops... These are the great questions....

Cheers Josh from Oz.

[Big T]

First thing to check is, does that cheap filter block the openings on the mouth of the carb?

Buy a better filter with an integral bellmouth, or, better yet, an airbox

Your symptoms and testing indicate an air leak, lean running condition

The mixture screw only controls idle mixture, set it per spec

Some people progressively add tape over the filter to achieve the proper fuel mixture. It's the same as putting your hand over it, or using the enricheners ( choke)

[rphillips]

You didn't mention jet sizes. Not familiar with the GS125 but most any bike that goes from OEM airbox and filter to Pods will need LARGER jets. If you are trying OEM jets, good chance they won't work right... Just my opinion.