2 Stroke problems, again!

[MattWadz]

Okay, 50cc Two Stroke Peugeot, Liquid Cooled, Sports Exhaust system (Doppler) standard 12mm Gurtner carburettor.


When i first start the bike, it will idle fine, but when i try to accelerate, it splutters alot as the revs go up, from cold ish as if its clearing its throat sort of thing

Once its up and running it will run well, as soon as i give it hard acceleration or just ride it normally for about 1 minute, when i take it back down to idle and try and pull back off again it seems asif the engine is dying, asif someone is slowly smothering it, and even when i give it throttle when this is happening it just seems to bog. if i wait and restart it, it will be okay but still spluttery.

Any ideas on what this could be?

i thought it could be a mixture issue but im lost as to where to start, too rich too lean, id rather find out first because its quite awkward to keep taking the float bowl off to change the main jet!
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Pitbike x2, Mini Moto x4, China Quad, 02' Suzuki AP50 > 03' MBK Nitro > 86' Suzuki GP100 > 02' Yamaha Jog R > 57' Honda Lead 100 > 95' Piaggio ZIP Rst 50 > 51' Suzuki TS50x > 83' Honda CB125TDE Twin > 51' Yamaha Aerox > 98' Kawasaki KX60 > 89' Yamaha DT50MX > 80's Honda QR50 > 05' CG clone > 125cc China Pitbike > 91' Honda MTX125 RW-L > 09' Peugeot Speedfight 2 LC LR > Lucky MX 140cc > Apache Tomahawk 50 Quad (current = 2010 Yamaha WR125R

[SQL]

plug chop it

[MattWadz]

plug chop means run it flatout under load and then quickly shut it off, whip the plug out and check it for colour right?

tan brown/coffee colour?
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Pitbike x2, Mini Moto x4, China Quad, 02' Suzuki AP50 > 03' MBK Nitro > 86' Suzuki GP100 > 02' Yamaha Jog R > 57' Honda Lead 100 > 95' Piaggio ZIP Rst 50 > 51' Suzuki TS50x > 83' Honda CB125TDE Twin > 51' Yamaha Aerox > 98' Kawasaki KX60 > 89' Yamaha DT50MX > 80's Honda QR50 > 05' CG clone > 125cc China Pitbike > 91' Honda MTX125 RW-L > 09' Peugeot Speedfight 2 LC LR > Lucky MX 140cc > Apache Tomahawk 50 Quad (current = 2010 Yamaha WR125R

[andys675]

faulty auto choke?
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Some people feel the rain, others just get wet.

[MattWadz]

could be auto choke, although im pretty sure it works fine because when i start the bike from cold, it idles high for about a minute, and then the idle drops back down to normal then, surely this indicates that its working correctly?

I could be wrong!
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Pitbike x2, Mini Moto x4, China Quad, 02' Suzuki AP50 > 03' MBK Nitro > 86' Suzuki GP100 > 02' Yamaha Jog R > 57' Honda Lead 100 > 95' Piaggio ZIP Rst 50 > 51' Suzuki TS50x > 83' Honda CB125TDE Twin > 51' Yamaha Aerox > 98' Kawasaki KX60 > 89' Yamaha DT50MX > 80's Honda QR50 > 05' CG clone > 125cc China Pitbike > 91' Honda MTX125 RW-L > 09' Peugeot Speedfight 2 LC LR > Lucky MX 140cc > Apache Tomahawk 50 Quad (current = 2010 Yamaha WR125R

[andys675]

remove the auto choke when cold, and wire it direct to the battery one lead positive and one to the negative, measure how far the brass valve on the end sticks out, after 10 minutes there should be a distinct difference between the two measurements, over 1cm iirc, if there is the auto choke is fine
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Some people feel the rain, others just get wet.

[MattWadz]

what causes the auto choke to move? is it just a timer or resistance?
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Pitbike x2, Mini Moto x4, China Quad, 02' Suzuki AP50 > 03' MBK Nitro > 86' Suzuki GP100 > 02' Yamaha Jog R > 57' Honda Lead 100 > 95' Piaggio ZIP Rst 50 > 51' Suzuki TS50x > 83' Honda CB125TDE Twin > 51' Yamaha Aerox > 98' Kawasaki KX60 > 89' Yamaha DT50MX > 80's Honda QR50 > 05' CG clone > 125cc China Pitbike > 91' Honda MTX125 RW-L > 09' Peugeot Speedfight 2 LC LR > Lucky MX 140cc > Apache Tomahawk 50 Quad (current = 2010 Yamaha WR125R

[lukamon]

if its like most scooters, its a small cylinder full of wax that expands (contracts?) when heated and it melts, pulling in (pushing out?) the pin. if the heater fails, no movement, choke stays on, bike runs shit
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killa wrote: Im an ass man myself

[evoboy]

Has it been jetted up to suit the new pipe?
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Suzuki GT250 x7------- Fazer 600------CB250RS------Aprilia Rally 70----- Bandit 600

APT Motorcycles

[Boxing]

[MattWadz]

It has covered about 1 mile since ive had it, with a brand new barrel piston head, and crank. im not sure what jetting would have been standard! i think thats the issue!

also, it wont start unless i cover the air intake on the airbox, soon as its started i can take my hand off then :S

So spun out!
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Pitbike x2, Mini Moto x4, China Quad, 02' Suzuki AP50 > 03' MBK Nitro > 86' Suzuki GP100 > 02' Yamaha Jog R > 57' Honda Lead 100 > 95' Piaggio ZIP Rst 50 > 51' Suzuki TS50x > 83' Honda CB125TDE Twin > 51' Yamaha Aerox > 98' Kawasaki KX60 > 89' Yamaha DT50MX > 80's Honda QR50 > 05' CG clone > 125cc China Pitbike > 91' Honda MTX125 RW-L > 09' Peugeot Speedfight 2 LC LR > Lucky MX 140cc > Apache Tomahawk 50 Quad (current = 2010 Yamaha WR125R