BSA b44/50

I have managed to start my b50 with my new knee
And I can now get my foot on the rear set and change gear
So I have been out riding it today all was going well until this evening when it blew a fuse on the way home from the pub
I changed that then further down the road I noticed the headlight switch had sparks coming out
And the switch was now loose blew another fuse
The only thing I could think to do was jam my gloves between the switch and the speedo and rev counter to hold the switch in place!!!
This worked ok and got me home
I heard it misfire just before you changed up from 2nd to third as you were passing the car, the EI if its fitted can have a rev limiter or your engine is running off at high revs.
As I have been riding again and the revs have increased the higher rpm misfire has returned
It had classic drain the float bowl symptoms IE you couldn't sustain higher revs without closing the throttle now and then
I took the float bowl off and has the tiniest needle valve jet I have ever seen
Now changed to a normal one