hot starting

[Z1B Alan]

i have a z1b which is totaly standard aside from being fitted with z1r carbs
my problem appears to be a reluctance to start when warm/hot.
when cold the bike fires up first prod on the button, any simple checks i could do to try to find the problem carbs have been balanced, ignition timing is spot on (electronic) valve clearences all checked, plugs cleaned and gapped any ideas folks

[Pigford]

Assume shes spinning over normal speed (not sluggish s/motor).
Zeds being air cooled tend to get a bit hot, so fuel vapourisation is not uncommon. The fuel evaporates from the carbs, thus emptying them a bit, so sometimes need a few turns to prime 'em again
Other than that, could be electrical Coils could be breaking down, as electrics experience more resistance with heat, especially windings in coils, alternators, starter motors, etc.
Sorry this don't narrow it down much

[uk kev]

I have some questions to try to help find the answer...

1. is it hard to start when warm on both the side and center stands.
if it is only hard to start after being on the side stand this is due to fuel migration.

2. is it hard to start on both the kick start, and the button.
if it is easier to start on the kickstart when warm, this is spark related, as the coils are getting more power from the battery than when using the button.

3. have you tried using the choke when warm.
if it starts on the choke when warm, this is a fuel starvation problem caused by evaperation.

[Z1B Alan]

thank's UK KEV have only just got the bike on the road so i will investigate further your suggestions and post the results, any further ideas welcome

[ROZZER]

Put some petrol in it yer tight wad! Works a treat.