When it is cold or left for few days, my Yamaha Tenere 3aj will not start with choke in on position. When hot it starts without problems.

Strange thing : bike can be started without choke, after some time when cold (winter 0 c) . It does not use oil. Fuel consumption is normal.

It could be the float chamber leaking fuel when stood a while like over night and re-filling when you are trying to start it.
Is your choke working ?
Cheers
Ian

Igrujin, are you opening the throttle at all when you start the bike?

My XT600 2KF (1989) kickstart only is a PIG to start if I even LOOK at the throttle.
I put choke on, 2 kicks and she will start, sometimes takes 3, as soon as she fires I can give it some throttle, but if I try to before she runs, she will flood and I can be there for 30 or 40 kicks before she fires or I collapse, whichever comes first!

Once warm, first kick, every time.

Just a thought..

Martyn

If I use choke, I do not open the throttle at all. But it will not start. If I open the throttle (not much) without choke and close it quickly there is a chance to start on cold. I do not know for choke. The cable is ok.

If my 3AJ does not start after 2/3 attempts on the starter I switch off ignition leave for about 1 minute switch back on and it will usually start stright away.
My other 3AJ had problems starting I stripped and cleaned carbs several times checked electrics changed battery no better.
I then sent my carbs to Dave Lambeth to be serviced, It is now the easiest XT to start I only have to touch the starter and will fire up stright away weather its hot,cold,wet or even been on its side.

Have you checked the carbs seat properly into the rubber stubs?

(I have rebuilt my carbs, new Diaphragm, needle valve, cleaned jets and airways, new gaskets, set up correctly as per the book.)

another thing to check is, daft as it may seem, is the Spark Plug NEW and correctly gapped, as well as that check the HT lead and the Plug Cap.

Martyn