2 stroke bike engine

[crankedup]

has'nt run for a couple of years, drained old petrol out and cleaned carb out. Engine starts but dies almost immeadiately. Done this too many times now any indicators as to where to look for fault please.

[deltafox]

Has it got points??? If so, take a look at changing the condenser, these fail and give the same symptoms.

[Incorrigible]

How have you cleaned the carb ?

I only ask, because it sounds like it's a blocked main jet and tit's running on the choke jet (if it started and runs for up to 5 ish seconds)

if you didn't, remove the bottom of the float bowl and look really carfully at the bottom of the main jet

If you did, then I'm probably wasting your time

[Pigeon]

What he said... also other fuel-starvation-y things... is the needle valve clear? is the fuel filter full of shit? is the tank outlet clear? does it have one of those stupid vacuum-operated fuel taps which usually don't work after a bit?

[telecat]

Does it run from a stator? if so it could be that. Also Blow thru the Carb using an air line, check the Air filter and airbox don't have any muck in them. As mper previous post's sounds like a stavation problem and all the above and previous posters suggestions can cause that problem.

[crankedup]

Well done guys, turned out to be a blocked jet, cleaned it through and hey presto. Starts first time and runs as sweet as a sweet thing. Matt bought it as a runabout on the road, its a 125cc Yamaha RD 2 stroke of 1985 vintage. Memories are a cloud of blue exhaust fumes

[telecat]

Would that be a Square tanked "roberts" twin????