zx2r won't start when warm

Hey guys, got a 89 zx2r, just got it back from mechanic for service and some other little bits. battery is relatively new
. I turned it on this morning and let it warm up for 10 mins or so with the choke set to around 4000rpm. had to turn it off for a few mins , when to start it again but it wouldn't turn over, sounded like the battery was also getting drained as it tried to kick over. Any thoughts?

My mate has this bike and had the same problem - try testing the rectifier.

.... and let it warm up for 10 mins or so with the choke set to around 4000rpm...... Any thoughts?.......

yep. Start the bike on the choke, let it idle high for like a minute or 2 - then start riding.

Idling at 4000rpm is not a good idea for any motor - ever. No motor needs that much warming up, and you will find that the motor warms up heaps quicker when you ride the bike anyway, not under a 'no-load' situation like you have described.....

and yeh, check the reg/rectifier as well as the stator output. Easy test is to just put a voltage tester across the battery terminals - with the bike idling at 4k, the voltage reading should be up between 13.5 and 14 volts....

I have one of these, take off the tank and check the connector to the rectifier, if its burnt, you'll find your rec is overcharging. The standard one is not exactly the best, and can be replaced with a mosfet one with a little bit of fiddling, alternatively, you can stick another rec from a later model on. These bikes normally have 5 pin recs, but you can put a 6 pin on, no harm done. Need something will a bigger heatsink.