Motorcycle Repair: 1970 triumph 650 single carb. help!, fuel evaporation, triumph 650

Question
dear chris, I ride a 1970 triumph 650 tiger and have recently discovered a new problem. The bike rides fine, it idles fine. Idles warm at around 1400 rpms. As I sit at a traffic light in neutral and engage the throttle to take off the bike spits and dies out instantly. This happened last night at 1 out of every 4 stoplights, give or take. This is the only time the problem occurs and if I am in neutral at the stoplight revving the bike before I engage in first it seems not to die.
Please help.(p.s. This all happened after coming back from having a boyer electronic system and a tympanium box installed). All help will be greatly appreciated and will get me on the road again without the embarrasment of having to push my bike off the road while 20 cars are honking at me.(new york city)
Please email me at lmnopq@mail.com or call at 646 485 1053
Thanks once again
Fellow rider
_Q


Answer
Hi Q.
 Fortunately, you have replaced the Lucas (the prince of darkness) electrics.

Being as you are in NY, I imagine that the bike spends time in seasonal storage every year.  The problem that you likely have is one involving the carb.  It is likely due for a good cleaning to get rid of the "varnish" that has built up over the years from fuel evaporation.  It may only need a really good fuel treatment dumped into the tank (use the entire bottle in one tank), or it could need a proper cleaning.  Whichever you do is up to you.

Unless you have gotten faulty electronics on the bike, which is not very likely, then the carb could be the only reasonable thing it could be.

Good luck.
FALCON