I have a 1996 Yamaha YZF750r that's in truly good condition.  On a cold start the choke needs to be engaged, no problem, the bike warms up and I can close the choke after a minute or so.  The bike idles fine.  I also noticed that even after I've ridden the bike for an hour, if I leave it sit for 10 minutes, then restart, I need to apply full choke otherwise the bike will stall.  Plugs are clean, oil is clean and there's no hesitation (acceleration / deceleration is smooth) while riding.  Just curious to know if anyone's experienced something similar and what to check for.

Appreciate any suggestions!

A lot of bikes do it. It prob means the mixture may be a little lean at idle (due to a pipe maybe, filters?).

Once its running its fine just a little too lean to fire. Is it better on a smoking hot day? My TDR does it unless the weather is really warm.

I certainly wouldn't worry. Check the plugs if it is bothering you. Colour of a nice smooth white coffee is what you want to see.

Thanks for the reply!  Yes, the bike seems better on those smoking hot days.  I'll pull the plugs and have a look.  The person I purchased the bike from took really good care of it but I don't think anything's been done tune-up-wise so I plan on taking it to a professional for a once-over.

 

cheers,

 

The principal of  a choke [ enricher]  is that  fuel vapour   condences on the cold cylinder [ head/valves on a 4 stroke] [ barrel/piston in a 2 T.]

Hence the need the richen the mixture when cold, ,,