Not Running On 3

Has it been sat unused for a long time?
I have a Thunderbird, same engine etc, which ran rough when I first got it.
It wasn't until I had chance to use it regularly that it sorted itself out ‍♂️

 

Errr.... not sure what that symbol at the end is about!

 

Valve clearances are?

 

Any idea when valves were last checked, if at all? Should be done every 12000 miles.
With luck you may get way with running redex or similar ( if you can get it I believe Seafoam is good) in the tank for a couple of fill ups, could well be a tiny blockage in pilot jet.
How did you clean the carbs, spray or ultrasonic clean?

 

Busa99
Sounds carbs to me. Make sure all the carbs are synced properly and like yous say get a good run or two on it.
Joe.

 

I know you mentioned plugs and coils but have you been able to swap around the HT leads, or replace? I had a HT lead go bad on me although that caused problems when warm, so probably not your cause, but it is a simple swap around if the leads are long enough, just to rule it out.
I also had poor running on some older fuel, I used some forte moto power (I think it was I not II) and added some esso 99 non ethanol fuel, once the tank had run through, the bike was running perfect again (2002 trophy 1200, so also with carbs). Good luck, because I always thought those versions of the 900's were one of triumphs best.

 

My money is on blocked pilot jet. You hsve to poke them through.