Por Apache 125 carb tuning, please help!

cactusmelba · 08-10-2015, 07:45 PM

Hi all, it's been a while as stupid house projects got in the way of my bike project.

The story so far: I've rescued a neglected 125 (based on the gy series I believe),

and started to try to build a street tracker out of it.

Having ripped the airbox out and installed a pod filter, it wouldn't run well at all, or even start well.. I ordered some jets for the carb, and started working incrementally up in size until a mate tells me that it'll definitely need the biggest one if I've installed a pod filter. So I installed the biggest jet, (I think it's a 115, up from 95), and sure enough it starts first kick every single time.
On the road however, it's utterly powerless. It doesn't seem to want to rev any higher than about 2k revs, UNLESS I reach down and tickle the choke a little, in which case it runs faster and revs freer. So that implies to me that it still needs more fuel, right?
The tickover screw is on the right side of the carb, (ignore the moth, it's been a while since I tinkered..)

but bang in the middle, underneath the carb, next to the rubber inlet manifold, is a small adjustable screw that feels like it's on a spring or something, almost ratcheted. Is this likely to be some kind of mixture adjustment screw? Here's a picture of it, it's the little brass coloured one, opposite end of the pod filter.

Is this the screw I need to be messing with to make the mixture more rich or more lean?

Any help would be greatly appreciated, as the manual seems to only tell you how to take the carb off, clean it, and put it back on again!

Thanks.

08-10-2015, 07:45 PM	#1
cactusmelba Join Date: Dec 2013 Location: the dirty stinkin UK Posts: 71	Por Apache 125 carb tuning, please help! Hi all, it's been a while as stupid house projects got in the way of my bike project. The story so far: I've rescued a neglected 125 (based on the gy series I believe), and started to try to build a street tracker out of it. Having ripped the airbox out and installed a pod filter, it wouldn't run well at all, or even start well.. I ordered some jets for the carb, and started working incrementally up in size until a mate tells me that it'll definitely need the biggest one if I've installed a pod filter. So I installed the biggest jet, (I think it's a 115, up from 95), and sure enough it starts first kick every single time. On the road however, it's utterly powerless. It doesn't seem to want to rev any higher than about 2k revs, UNLESS I reach down and tickle the choke a little, in which case it runs faster and revs freer. So that implies to me that it still needs more fuel, right? The tickover screw is on the right side of the carb, (ignore the moth, it's been a while since I tinkered..) but bang in the middle, underneath the carb, next to the rubber inlet manifold, is a small adjustable screw that feels like it's on a spring or something, almost ratcheted. Is this likely to be some kind of mixture adjustment screw? Here's a picture of it, it's the little brass coloured one, opposite end of the pod filter. Is this the screw I need to be messing with to make the mixture more rich or more lean? Any help would be greatly appreciated, as the manual seems to only tell you how to take the carb off, clean it, and put it back on again! Thanks.
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