50cc 2stroke sportsbike starting/idling problems

[irishguyadam]

Have a 2 stroke \derbi gpr50 sportsbike with 80cc kit.
Bike has new battery, new ignition barrel, new spark plug.
Carbs are clean, float and rreeds seem ok.
No starter motor at the minute.

Bike bump starts but wont stay running more than a second or two before cutting out and rear wheel locking.(second gear)
Any ideas?

Air filter is soaked in petrol from a recent tank leak and has one or two small tears in it, could that be a reason for not starting?

Also the main fuel line going into the carbs seems to be a DIY job from the last owner, it is longer than nessecary and as a result it is not a straight down drop for the fuel. This a problem?


Im a mechanical newb by the way: the valve at the underside of the petrol tank has two outlets on it, one for the main fuel line which goes straight to carbs, the other has no pipe/hose on it at all any idea what should be on it? the only unattatched hose that will fit it is another hose that is attached to a small brass valve on the cylinder.
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I like engines, but they dont really like me

[jaffa90]

Two outlets sounds like a vacuum operated fuel supply connected to the inlet manifold.
Any pics?

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2 carbs on a 50 bored to 80cc?

If it's locking the rear wheel, are you sure it's not running very lean or with no 2T oil?

Is it premix or autolube, if premix, what ration? If you don't know this, stop trying to start it until you do.
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