Trophy Stalling When Braking Hard(ish)

If I brake and cause the front to dive, as one comes to a stop and clutches in, the engine stalls.
I can coast at any speed and pull the clutch in and it'll drop to idle no problem. But if I grab a handful of brake even at low speed turning around on the drive, it stalls. So its only when I 'dive'.
Idle is about 1000rpm.
any ideas?

 

But I had cool parts today!
Hot happened with just 1 gallon in tank, today i filled up.

Its almost like theres a tilt switch.

 

Well I've upped the idle RPM up a touch (and balanced the carbs, though I don't think thats relevant to this issue) and still the same.
The odd thing is it will cut out even if I push the bike and grab a handful on the drive, in neutral too. So i don't think its fuel starvation/ tank breathing issue, nor a dragging clutch issue.
Looked for a tilt switch but I think its on the (newer) 1200's, can't find one on this, please enlighten me if I'm wrong.
Battery terminals are tight and its strapped in properly.

Any other suggestions are welcome.

 

Cheers. No problems when braking gently, only on the dive. I've given the loom a quick wiggle and it was ok, but I think I shall investigate further today.

 

Update:
Went out and collected 100 miles worth of assorted bugs today and have come to the conclusion that its fuel related and not electrical.
Upping the idle to 12 or 1300 has made it a little less prevalent, and when it does die its a slow death not a sudden 'off'. I can of course ride sensibly and it doesn't happen, but I'd like to get it sorted.
I also worked out I can make it die by sitting on the back of the bike whilst on its centre stand and bouncing so it rocks rapidly. The idle just gets lower and lower until it cuts out.
Opened the fuel cap, to eliminate any potential air lock scenario, and tried it on Res, On and Prime. All the same.

Possibly float height incorrect? Can the float height be affected by the dive/rocking?

Suggestions on a postcard please.

 

I did try but my phone battery was flat

I also had a good tug around all the loom and switchgear etc and not a moments misfire or fluctuation in rpm. Coil connections were checked, clamped and copper slipped while the tank was off the other day.

Just had a thought! the previous owner said something about the vacuum part of the petcock not working. The hoses and connections were sound but maybe there could be an air leak in the petcock? I shall clamp the pipe off tomorrow and see if makes any difference.

BTW Once it does stall, it starts immediately on the button, well two or three turns of the starter, same is if starting any other time.

 

Willing to try anything that may have a chance of working
Witch doctors and wizards are welcome

 

More than happy to check it if someone can tell me where it is
'97 trophy 900

 

But mine has carbs and gravity fed fuel - no pump etc, so I think I may not have one? Happy to be proved wrong though.