Modern Vespa

I cannot get my '02 ET4 125 to start, I have reprogramed the imobiliser and it seems to be functioning OK as I have a good strong spark.

Have checked the following:

Spark - Good
Fuel - Carb filling and primer working
Battery - Fully charged

I cannot see any obvious reson why it wont start, can anyone suggest ayhing else to look for as I'm running out of ideas.

Hi Steve D

is there any sign of life when you press the starter button? any turnover etc.
have you tried kick starting it, (not a good idea for day to day starting)

if there's no response from the starter button it could be an electrical problem, fried connection etc. especially if it starts on the kick.

it does take a bit of effort to kick start it, when I got my ET4 it was a bitch to kick start.

The starter motor is fine, turns over ok on both starter and kick start, and I get a good spark from both starting methods.

Does anyone know if there is any timing adjustment?? I'm currently presuming this is fixed like most modern single cylinder engines and can only be varied electronically, so should still be correct.

Also is there any procedure that should be carried out after cleaning out the jets in the carb other than ensuring that the float chamber is primed? As I cleaned the carb out prior to the staring problem occuring.

Check to see that the carb is actually attached to the manifold. That's what the problem was with my friends LX when everything else was firing.

Sounds like you've flooded the canister (very common). Disconnect the evap hose:
ET/GT/LX: Hard Starting, Rough Idle, or Stalling

Done and dusted.

The evap hose has been removed already by the looks of it and the top of the carb looks slightly different to the one in the photos. Thisnk this may be down to it being a UK model.

Still cant get it to run though.

Is there any service information available for the Leader carb? am thinking I may have disturbed something when cleaning it out.

When you say you "reprogrammed" the immobilizer, are you talking about resetting your key? Do you have the original brown key and the blue key?

Mine does that to.
The battery post needs to be cleaned when it happens at my house. Its happens every few months and there is very little build up on the post it will not start but will turn over clean the post and re-connect.

good spark and right amount of gas should start.........suspect gas-air mixture problem; try this useful trick >remove air intake large hose from back of carb .......turn hand grip throttle all the way so throttle plate in carb is open all the way >hold o pen while you give a good shot of starting fluid (ether) into the open carb......wait a few seconds and release throttle (hand grip) > now start engine <

Thanks for the input, unfortunately still no life

Reset the blue key using the red/brown one.

Am going to strip and rebuild the carb as the problem only started after I cleaned out the jets.

Does anyone know if it is possible to re-program the CDi and if so how it's done as the only other thing I can think of at the moment is that the timing may be out??

well taking the carb apart again, re-cleaning it etc and putting back on could help....sometimes unexplainable things just work....
have you tried starting it at WOT? ive been messing with the timing on mine and sometimes it doesnt start unless WOT. (im only messing with mine until my new goodies arrive)

I bet the problem is with the jets.

I caught it once after pulling my main out.

I 'thought' I had it wound all the way in but something made me look again and it still had an eighth of an inch to go.

The jet actually is seperate to the tube it sits in, so there are two sets of
threads to mindful of.

If the tube wound out and you didn't notice it's probably sitting in the fuel,
in the float chamber, flooding the bejesus out of it.

How did you clean your jets?

didn't poke a rusty nail down them did you?

anyway, for poor starting it's probably a blocked/not correctly seated
primer jet (the little one)

I've cleaned the jets through with compressed air, seem to be clear and everyhing seems to be seated properly, but presumed that the first time round too.

Have also checked the diapraghm and auto-choke, both seem to be functioing correctly, or at least as described in the LX workshop manual.

Now have the carb back in one piece so will be re fitting this eve when I get home from work and will let you all know how it goes.