83 GPZ250 no start when cold

mattsar1 · L Plate Warrior Joined: 06 Aug 2006 Karma :

Hi!
I have just got my learners and bought a GPZ250 of a guy and it was running fine..... when hot. But when it is cold, it just wont fire up. Choke on, choke off. Full throttle, no throttle. Push start, or jump start, still won't go.
I can squirt some fuel into the cylinders and it will fire and run, but if you blip the throttle it will sometimes just stop. You have to carefully rev it up to keep it running then it is fine, untill the next morning.....

Things i know
Carbies clean.
Diaphrams not split.
Good spark.
Compression OK.
Tappets not tight.
Runs good when going.
Seems to tick over fast enough on the startermotor.

Can anybody help with some ideas!
Thank you.

finpos · World Chat Champion Joined: 13 Sep 2005 Karma :

Just sounds like your actual choke is not working. Simple check would be to make sure that something on the carburettor moves when you put the choke on/off - ie. check the cable is not broken. Anything past that, you will probably have to strip the carbs down.

finpos.

mattsar1 · L Plate Warrior Joined: 06 Aug 2006 Karma :

The choke is working and the carbies have been stripped down and cleaned a couple of times now.
Perhaps there is some special way to set the choke up??

finpos · World Chat Champion Joined: 13 Sep 2005 Karma :

Setup of choke is normally just a case of making sure there is a bit of slack in the cable, so that you are sure that it is not on when handlebar lever is in the "off" position. It seems yours is not coming on, so doubt if that is the problem. You should check this is correct in the manual, though.

You say you have stripped down and cleaned the carbs - have you actually checked the cold start jet (assuming it has one, which I think it will) is clear??

finpos.