hi folks, have had a little check for common problems but thought people may be able to shed some light on my issue:

first race meeting the other day and the bike started first time on the button with choke

needed a bit of throttle the second time (having cooled down an hour or so later) along with choke, but went fairly easily

third time needed a bit more persuading with the throttle, and help to idle until warm

fourth time, nothing... turning over fine, but not even trying to fire

not sure if its related, but mainly out of right handers with a bit of lean, if out of the power band it was spluttering a bit, and popping but running fine once into the power.
on examination after not starting i found a block connector melted under the tank by fuel pump but bypassed that today and still same problem....?
starter motor, and fuel pump both working fine. in the short time i've had it its started first time with choke... it has a race airbox thing under the carbs, so will take them off tomorrow to look at plugs.

any help would be greatly appreciated. are there any common things to fail on these race bikes?

Ta!

pics tomorrow

Not charging up the battery between outings if it's a total loss system. As the battery losses it's charge the sparks get weaker

hi thanks for the reply. almost certain it isnt the battery, i thought it might be total loss myself but fully charged it when i got home and still not firing...
will check leads and plugs first and work back.
are there any bits prone to failure on racebikes? coils etc? thanks

As you say ... renew the plugs and see if they spark, if they both don't then suspect the coils ... or the crank pick ups - it could be the wires from the pickup aren't connected

Check your tank isn't rusty & check the filter (you must have one or you will block the carbs) I had to coat the inside of my tank with petseal as the filter was getting blocked with very fine rust after every session on track.
I would also check the carb float levels as if one or more are to high it my flood the engine when you lean over.
Coils also brake down with heat so could have got worse as the day went on, although both would need to of gone at the same time to stop it firing altogether. As the Evilman says check the pick up's & swap the cdi if you have a spare, these bikes are now getting on for 20 years old so check the electrics very carefully for duff plugs etc.
Hope you sort it out soon let us know what it was

Thanks for the replys.

Can rule out fuel problems immediately, tank and filter spot on.
Carbs seemed fine, but checked electrics with a multi meter and all is spot on except out of the cdi only one of the connection points gave a reading - almost certain that is the source of the bother.

Will see if it can be fixed, or if not will have to get a new one...

Why not trace where that wire comes from ... it might be a supply wire ... then see if that bit's working.

On the 3EN there's a big flat diode block, I had a wire broken where it went in there and it nocked loads of stuff out.

ok so got the bike running again thanks to a new cdi unit, everything else was fine, also changed plugs while i was digging about in there, going to get it dynoed tomorrow to see if the new unit is making similar power to the old one....

brilliant, ecu working fine so got it on the dyno today to check all is well before race meeting this weekend........and now the clutch is fried!!! apparently no-one keeps spares either.....
what a pain in the arse! but at least she was spitting flames on the overrun before it broke ...or was that just bits of the burnt clutch coming out the exhaust....?!

that's bad news .... any idea which bit let go ?