Why wont it start

[vinrouge]

6 weeks later and still not firing.
Pk50 112polini, polini lh, carb16.10

Stator been sent away and comes back with a clean bill of health
New plug, lead, cap, sparks as it should
Carbs been cleaned 3 or 4 times.
Compressions bout as good as it gets.
Petrol flows fine.
Cases split nothing obvious.
gas passes through and out exhaust.
Petrol syringed into cylinder but not a splutter

Just cut out one day after about 6 mile riding and never fired since. It's like it wont spark in the cylinder.

[guy160]

Possibilty of new plug being defective. Its possible for a plug to fire outside , but not work in the engine.
Also...has flywheel been off since it broke down? If not, take it off and check woodruff key hasnt sheared. If it has, the timing could be so far out that despite good spark, fuel etc it wont even try to start.

[tony]

Try a new fuel mate.. if still no then CDI.

[vinrouge]

Cheers, always helps to get some fresh ideas.
I hope it don't turn out to be the CDI, as I almost brought a new one off ebay for about £20 when the problem first started, decided it wouldn't be the fault as I'd got a decent spark.
Must admit I've not thought about timing so its something that needs looking into.
Fresh petrol is easy enough to try.
thanks
Rob

[smallyshane]

Hi mate, had similar probs a few times myself, simple things frst, Spark plug, ave had real problems with the NGK ones...

And CDI, swapped out for a go kart one.

The CDI one was cut out and wouldn't start, and the plugs generally wouldt fire up (some ties would fire but not rev), but ran fine up until it came to start again..