2003 Suzuki Bandit GSFs 1200's Choke and Carburator Knob

i am a bit new to the bandit scene and have some questions about the two

when i want to start the bike in the morning i pull the choke lever for a minute or two then start the bike 

i was told that i need to open the carb a bit until reps get to the 1000 area and then close it again

but i never know how much is too much or too less 

i dont know when the bike is running lean or rich as most ppl say in forums

when i turn it a bit more the engine noise increases and when i turn it the other way the engine seems like it wants to stop 

sometimes even after opening the choke and having the carb knob in the middle of the range the engine stops. i dont know if i am doing something wrong and causing more damage to the engine or is it just the way how these old bikes operate 

help plzz tnx 

I’ve only got a single level; which simplifies matters some what.

an engine which runs lean you can tell because it struggles to make the rev range; or lags in acceleration (blip the throttle and it will be delayed responding.) or indeed just dies when you open the throttle. For a rich engine; it starts to run lumpy and goes bop bop bop and then dies…

If you’re having trouble; worth checking air filter & spark plugs first. Mine totally changed character once I had new spark plugs fitted.

It’s been a few years since I used a bike with a choke but generally
when warn tickover should be around 1200 rpm
With the choke pull it out when cold and once warm push it back

To check the mixture pull the plugs out and check the colour 

They should be light brown 

If they are blue white then the bikes running lean 

If they are black then it’s running rich 

Bandits are pretty reliable bikes 

Most off all if your not sure don’t fiddle 

Take the bike to scorch and let him cast his eye over itv

I think you’ll find all the carb knob does is to increase the revs some, bit like twisting the throttle a little. Over use should do no harm other than to increase the engine temperature while reducing the fuel economy, this is because the engine is ticking over faster not because its running rich.

The choke does just what it says on the can, it chokes the air intake at the carburettor venturi by means of a butterfly valve which in turn increases the fuel to air ratio.

Things to have checked include 

  1. Carburettor - The internals should be proper clean, a spray can of carburettor cleaner is your best friend here but the carburettor will have to be stripped down to do an effective job. One clue to the cleanliness of carburettor internals is to look for a build up of grime around the venturi butterfly valve hinge, this grime can form into ice in cold conditions preventing the butterfly valve from opening/closing properly.

  2. Spark plug leads - HT leads deteriorate with age allowing water ingress which causes the core to break down, check their resistance while twisting, the resistance is sometimes printed on the side of the leads. If the resistance fluctuates or is greater than specified on the lead or is greater than about 20,000 ohms then replace them.

  3. Spark plugs, if you’ve no service history detailing their last replacement just replace them any way but as above check their colouration against one of the many online spark plug colour charts to be sure what’s happening with the air:fuel ratio.

  4. Air filter - Dirt or moisture in air filter or condensation in the air filter housing can form into ice in cold conditions. Check and clean or replace air filter as necessary depending on fitment type, clean the air filter housing.