1996 Triumph 900 Just Shuts It Self Off In The Middle Of A Ride

When the Leg-end keeping stopping, thought it was probably simple. Maybe the breather with the ball in it ..a la Ducati .. cut it off, nah ... drilled hole in cap and brazed in a decent sized tube, nah ... did some reading, aha ? New pickup, "Sprintdave" .. had a '97, (first injected year) for 7 years, loved it .. particulary holding off mates MV at (looks over shoulder) 145mph, and he says "Yeah, but I had a gear to go." hahaha .. in the excitement, I'd forgotten that Speed Triples had 6 gears too !! Working out the gearing, I only had 137mph, which completely ruins pub bragging ! For some odd reason, I still prefer it over the '09 1050 ... but son won't sell it back, (or even swap) ?