gsc1ugs Posted December 17, 2019 Share Posted December 17, 2019 This puch magnum x running bad - i need adjust or clean carb, what is the screw at the side for and how should it be set? Quote Link to comment Share on other sites More sharing options...
ThePhatomfart Posted December 17, 2019 Share Posted December 17, 2019 Think thats the idle screw , but have a look at this sitehttps://www.mopedarmy.com/wiki/Bing Quote Link to comment Share on other sites More sharing options...
Gsx750f boy Posted December 17, 2019 Share Posted December 17, 2019 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 ?? Quote Link to comment Share on other sites More sharing options...
Gsx750f boy Posted December 17, 2019 Share Posted December 17, 2019 Update ...if it's a mixture screw it'll be with very fine taper needle tip..hope this helps Quote Link to comment Share on other sites More sharing options...
fastbob Posted December 17, 2019 Share Posted December 17, 2019 I'm pretty sure that's a throttle stop screw . Quote Link to comment Share on other sites More sharing options...
Bianco2564 Posted December 19, 2019 Share Posted December 19, 2019 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 cleanIntake rubbers or seals Crank seals as suggestedAir leaks on crankcasePiston,ring and bore conditionExhaust not blockedIgnition condition,spark plug and timingFresh fuelIf 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 Quote Link to comment Share on other sites More sharing options...
Gsx750f boy Posted December 20, 2019 Share Posted December 20, 2019 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 cleanIntake rubbers or seals Crank seals as suggestedAir leaks on crankcasePiston,ring and bore conditionExhaust not blockedIgnition condition,spark plug and timingFresh fuelIf 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 leanfully 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 Quote Link to comment Share on other sites More sharing options...
Bianco2564 Posted December 20, 2019 Share Posted December 20, 2019 Other things I thought of;Float level and needle.Choke function and being operated correctly. Quote Link to comment Share on other sites More sharing options...
Gsx750f boy Posted December 20, 2019 Share Posted December 20, 2019 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 Quote Link to comment Share on other sites More sharing options...
gsc1ugs Posted December 21, 2019 Author Share Posted December 21, 2019 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 Quote Link to comment Share on other sites More sharing options...
Gsx750f boy Posted January 3, 2020 Share Posted January 3, 2020 Any update..???? Quote Link to comment Share on other sites More sharing options...
gsc1ugs Posted January 4, 2020 Author Share Posted January 4, 2020 Ive sold it running bad, was told it was wrong plug, get warm cuts out Quote Link to comment Share on other sites More sharing options...
Gsx750f boy Posted January 5, 2020 Share Posted January 5, 2020 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 Quote Link to comment Share on other sites More sharing options...
sparkpaintersuk Posted January 6, 2020 Share Posted January 6, 2020 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. Quote Link to comment Share on other sites More sharing options...
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