First of All I am an two wheeler's motorcycle Mechanic

problem:
A friend of mine have Bajaj Avenger 150
which have the problem of Delay in Self Start
how the delay in self occurs-
1st self starts
2nd self delay of 3 sec
3rd self starts
4th self delay again of 3 sec
5th 3 sec delay
6th starts
and randomly delays occurs
and when delay occurs , the display,reading etc goes off for 3 sec and turns on again.


tried solutions-

1. have changed the self start carbon brushes with original ones - still same problem
2. self motor is easily rotating and not jammed ,its free - tested outside the bike
3. have tried changing battery but - still the same problem
4. terminals are also not loose
5. changed starter relay - still same problem
6. checked the terminal voltage by multi-meter while performing self
when the bike starts it goes to 11.4v
and when it delays it gets to 4v for 3 sec
when ideal its voltage is 14.8v (battery+RRunit output)
Tried with new battery still the same readings.
don't know where the self is getting stuck for 3 sec as if it don't have that much power
but then after 2-3 self bike gets started as normal.

Ok so know i Need solution on this delay
as it is draining the battery
need suggestions of all please

Thankyou,