Post by pxmatt on Aug 14, 2020 8:53:24 GMT
Good morning all, hope you’re all safe and well.
I’m after a little guidance on the jetting of my carb. I know this is a hot topic asked by many and precise answers cannot be given, I’m looking for peoples help and opinions. My scooter is as follows;
PX125 with polini 177
30mm Dellorto PHBH with reed valve conversion (including ported crankcase mouth)
Scorpion exhaust (soon to be changed to SIP Road 2)
Set to 19* BTDC.
The current carb jet setup is
Needle valve 200
Main Jet 112
Idle 55
Needle X2
Starter 70
Atomizer AV262
Currently it is spluttering through the gears until you push through/passed half throttle. I have found the following website;
www.mbscooters.co.uk/info/mb-*-instructions/fitting-*-mb-engine-setting-up-*-part-2+151.html which appears to be what my scooter is doing, and to quote “when you set off the engine doesn’t clean up and splutters, like running if the choke is on (called 4 stroking - sounds like machine gun fire), and you go through each gear and still doesn’t clear, then your slide is too rich” I’m not sure what is meant when they say “slide is too rich” is this as simple as adjusting the air mixture screw? People I have spoken to say that my main jet is too small and that I should be running approx. between 125-132. Other than the above, the scooter starts within a couple of kicks if not the first.
Any advice and an explanation to the above would be greatly appreciated, I feel carb setting is a bit of a minefield
I’m after a little guidance on the jetting of my carb. I know this is a hot topic asked by many and precise answers cannot be given, I’m looking for peoples help and opinions. My scooter is as follows;
PX125 with polini 177
30mm Dellorto PHBH with reed valve conversion (including ported crankcase mouth)
Scorpion exhaust (soon to be changed to SIP Road 2)
Set to 19* BTDC.
The current carb jet setup is
Needle valve 200
Main Jet 112
Idle 55
Needle X2
Starter 70
Atomizer AV262
Currently it is spluttering through the gears until you push through/passed half throttle. I have found the following website;
www.mbscooters.co.uk/info/mb-*-instructions/fitting-*-mb-engine-setting-up-*-part-2+151.html which appears to be what my scooter is doing, and to quote “when you set off the engine doesn’t clean up and splutters, like running if the choke is on (called 4 stroking - sounds like machine gun fire), and you go through each gear and still doesn’t clear, then your slide is too rich” I’m not sure what is meant when they say “slide is too rich” is this as simple as adjusting the air mixture screw? People I have spoken to say that my main jet is too small and that I should be running approx. between 125-132. Other than the above, the scooter starts within a couple of kicks if not the first.
Any advice and an explanation to the above would be greatly appreciated, I feel carb setting is a bit of a minefield