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puch magnum x running bad


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If its a idle screw it will be tapered against carb slide ...u may have to adjust idle by cable thread on top if that screw is mixture...usually tighten very light in ( counting as u do to reset if adjustment no good) and unscrew 2 half out.very similar to my moped carb.could be poor condenser and if renewing it fit outside of mag set to keep cool( 2 strokes run hot and kill them)...is crank seals OK ??

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Don't know about this carb specifically but my thoughts.

If it has a very fine taper as Gsx boy says its the mixture screw basically adjusts the fuel/air mix at idle.Above idle then the pilot, main jet and needle position all play their own part in controlling the fuel. Plenty of charts online showing who does what. As to what yours should be will need you to find a manual.

If you can't I'd set the mixture screw about 1.25 turns out from fully home and the circlip on the needle (assuming it has one on a basic carb like this ) towards the bottom, i.e. the needle is lifted out the jet.Better to err on the rich side on a 2 stroke.


If its a throttle stop screw its probably got a rounded end which pushes on a angled face on the throttle piston, screw it in raises the idle.


Other things to check if its running bad;

Air filter clean

Intake rubbers or seals

Crank seals as suggested

Air leaks on crankcase

Piston,ring and bore condition

Exhaust not blocked

Ignition condition,spark plug and timing

Fresh fuel

If pre mix make sure the ratio is correct, too much oil and it will struggle to ignite.

2 strokes can be fussy about air leaks on the intake, either run bad or seize up if too lean

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:thumb:

Don't know about this carb specifically but my thoughts.

If it has a very fine taper as Gsx boy says its the mixture screw basically adjusts the fuel/air mix at idle.Above idle then the pilot, main jet and needle position all play their own part in controlling the fuel. Plenty of charts online showing who does what. As to what yours should be will need you to find a manual.

If you can't I'd set the mixture screw about 1.25 turns out from fully home and the circlip on the needle (assuming it has one on a basic carb like this ) towards the bottom, i.e. the needle is lifted out the jet.Better to err on the rich side on a 2 stroke.


If its a throttle stop screw its probably got a rounded end which pushes on a angled face on the throttle piston, screw it in raises the idle.


Other things to check if its running bad;

Air filter clean

Intake rubbers or seals

Crank seals as suggested

Air leaks on crankcase

Piston,ring and bore condition

Exhaust not blocked

Ignition condition,spark plug and timing

Fresh fuel

If pre mix make sure the ratio is correct, too much oil and it will struggle to ignite.

2 strokes can be fussy about air leaks on the intake, either run bad or seize up if too lean

fully agree with this but I'd put needle clip centre position first then move down as req.as far as I'm aware each notch on needle is a half jet size ???? I set up wee lads tuned pw50 and my Moby not standard either and my tuned 2 stroke xtc...carbs on 2t fine slow art.also careful of premix as engine may be running to weak if was running a pump ...ur maxi hasn't got one so would be premix from factory
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Also some mopeds (like mine)have a decompression valve in head to drop compression when starting.. Seen them stick slightly open with carbon and sometimes return spring sticks.....it's just like a tiny cyl head valve

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Well i cleaned the carb and that screw is the idle just pushes up the main cylinder in carb whatever its called, it was running rubbish so cleaned carb emptied tank gonna put 97unleaded with 2 stroke oil and ive put a filer on the back of carb will keep you posted

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  • 2 weeks later...

Maybe u should of checked plug type before post?? Br6hs?? I've just fired up my moped (2 stroke) which has lay since June not started, fired up after 20secs of pedal assist... Advice for future always turn off fuel on stroke and allow it to use float fuel up before storage 🤔

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Maybe u should of checked plug type before post?? Br6hs?? I've just fired up my moped (2 stroke) which has lay since June not started, fired up after 20secs of pedal assist... Advice for future always turn off fuel on stroke and allow it to use float fuel up before storage 🤔

 

Something learned here, thanks.

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