GSF 600 Bandit

What is it doing? Any sputter? When you pull the plugs are they wet with fuel?

There's only really, ignition, fuel and valve timing.

Assuming your good sparks are nice fat blue ones are they at the right time?

How is the valve timing controlled chain or belt...if belt...has it slipped?

Nice smell of petrol when you turn it over with plugs out?

Is the weather soaking wet? Is the spark leaking to earth by some other route once the plugs are in and under pressure? A good squirt of WD40 always helps, maybe some garlic around the fule tank if all else fails?

Good luck

Del

Are the HT leads in the correct sequence, and is the spark arriving at the correct point in each cylinder's cycle?

Did it just fail to start all by itself, or was it after doing some work on it? Was it running OK the day before?

It is most likely something simple. Example : some fuel caps do not seal the tank all that well. When it rains, a little water gets into the tank, and when you switch onto reserve the water makes the bike run rough or in extreme cases not at all.

Another example : a near-new DR650 starts OK, but half a mile up the road it dies. After a few minutes it starts again ok, but again dies a short way up the road. The problem? The fuel tank breather gets twisted when the fuel cap is screwed down, and stops the tank from breathing. Untwist the breather hose and all is sweet again.

Good luck, and do let us know what you find!

First of all... it is best to have excellent spark, good is often not good enough. The spark should be robust, filling the gap, not just a weak thread of an arc. Secondly, have you tried introducing a bit of fuel into the carb with the air cleaner removed to see if it will fire? If it does, then you have carb problems. Perhaps it is time for a carb overhaul kit or just remove and clean it, being careful to keep track of small parts.

Being the rider of a GSF1200, this is what I would try....Pull the right side cover and the number one plug. Verify that number one cylinder is at or near top dead center for your timing aspect. Verify particulars to your machine in the maintenance manual. Drain and refresh your fuel supply if there is any doubt as to it's volitility. Check that the intake and exhaust are clear, that mice have not taken up living in your airbox or such, it does happen. Drain fuel bowls and ensure plugs are clean and/or fresh. And don't forget to use the priming function on your petcock to allow fuel bowl filling prior to attempting to start. If all else fails, a short shot of starting fluid into the airbox may get it going. Use very sparingly though, it heavy doses it can burn pistons. At least that is what I have been told. Good luck.

Where's jasonwilliams1?

Do a compression check if the rings are bad it wont build pressure in the cylinder and wont "fire" as a result it wont start.