Ps won't start

[ducksta]

Hi guys. Just finished building a px 125 all standard. New wiring loom regulator etc. got a lml engine in it

Problem is it will not start, got spark to new plug , petrol to carb , all connections sound , and new ht lead. Have tried a different carb and stator plate spark at plug with key turned on no spark when off so think wiring is sound,, any thing else to try engine ran in mates bike before I bought it.

[holty]

hi, if you have spark and fuel it should run, is your plug is coming out wet after trying to start it you have an electrical issue, if dry its a fuel problem,thats presuming you have compression, i had an issue with my t5 it was caused by the fuel line being slightly too long and stopped fuel coming through, might be worth a look in the carb.

[ducksta]

Plenty of petrol changed carbs and at the bango it pisses out

[holty]

it must be electrical then, id start by disconnecting the wire on the cdi that goes to the ignition switch.have you tried another plug-maybe obvious but worth a try?

[hendy]

Timing could be way out.
Big air leak?
piston back to front?

[ipman]

Tighten your nuts

[paul d]

Might be time to get some friends over, forget about the kickstart and try pushing it in 2nd or 1st gear. How it runs after doing this often helps me diagnose the problem. Maybe the choke is stuck on/not connected, throttle cable not seated home properly in which case it'll rev, oil seal issue will rev too, dirt in carb or poor compression will require blipping of the throttle to keep the engine running, missfire could mean many things....good luck with it.

[ducksta]

Got me thinking dont know hoe old the petrol in the tank is so flushing out putting new in tried the green wire trick no joy buying some easy start to see if it fires then fault find back with everything everybody has said

[mick1]

You can always ask QMT.......probably fix it in a few minutes.....

[ducksta]

Ive seen his work he once took a full lambretta gearbox and clutch out just to change a cable