Im having an issue on a 93 import nc30, im not new to owning these bikes but this has me stumped.

A little background info. I bought a 93 import nc30 a few weeks ago, it started and ran but was dog rough. I checked the carbs are they where fubar, so I bought a 2nd hand set and did the strip/clean/rejet as in the guide.

Put bike back together, fired 1st time and ran perfect. Took it for a ride out at it couldnt have fueled better(fluke maybe).

Now whatever I do it wont start when stone cold, full choke no throttle, fires but wont catch. If I wheel the bike out into the sun for a bit it starts and runs perfect. With the days of having sun rapidly decreasing I need a fix.

I noticed with full choke it only revs upto about 1800/2k revs, im sure my old vfr/rvf would rev to about 3k then upto 3.5/4k when warmer. Ive checked the choke cable and arm and they are opening fully.

Im gonna strip her down again but need advise on what I need to be checking, the choke mechanism on the carbs looked and worked fine from what I could see when I had them off.

Fuel is fine, sparks ok, battery reg/rec all fine so im pretty sure its non of those.

Any ideas?

Is the choke cable opening fully ie adjusted correctly? May not be giving you full choke...

Its moving the actuator arm on the carbs over as far as it will go. Is there another adjuster on the carbs somewhere?

Anymore thoughts on this?

Is the idle adjuster set right? Full choke on a warm bike gives 4K or a little better on my RVF. 1800 is not a huge amount over idle, which ought to be about 1300. Also, did you balance the carbs after stripping them? I just wonder if the butterflies are just a little too far closed for it to be happy when very cold? Have you tried giving just a little throttle when attempting to start to see if it's a lack of fuel?

Yes everytime ive got it going was with a slight grab on the throttle when it seemed it was gonna catch. It then catches for a few secs then dies, usually starts again straight away after that.

Used the drill bit method to balance them when they where off the bike.

You think its worth adjusting the butterflies to be slightly more open?

It idles very well once its running.

It sounds to me like part of the choke circuit is blocked, I've come across this with nc30 carbs if they've been sat for some time with fuel in the carbs. The only way to rectify this is cleaning them in an ultrasonic bath.