daytona 675 44mm throttle body onto bonneville efi conversion
for anyone who wants to do this here is a breakdown of how i did it.
there may be some steps or details i have forgotten to mention but i feel that if you are competent enough to attempt this conversion then you should be able to work-out any omissions i have made.
the first thing i did was to remove the automatic idle control solenoid from the daytona t.b's.
then i started opening out t.b 1+3 down stream of the butterfly using sanding drums and a porting kit mounted on a flexi-drive shaft attached to an electric drill.because as standard the t.b's narrow down to an oval shape
(you need to use t.b1 because it has a blanking cap to cover the butterfly shaft nut and t.b3 because it has the t.p.s)
be very careful not to touch the machined part of the t.b where the butterfly sits as any damage here will prevent you getting a good idle and getting accurate t.b balance will be impossible.
also be careful on the lower part of the t.b that you don't take anymore than necessary because of the shape of the casting the t.b becomes thin here.
like this
once the t.b's have been "ported and polished" i then removed the butterfly spindle from t.b2 and installed it in t.b1(make sure you use a good quality phillips screwdriver because it is very easy to round off the heads of the butterfly screws).
this needs to be done so that the t.b connecting linkages are in the correct place(use the suitable spacers for the butterfly spindle securing nut).
to set the correct spacing of the t.b's cut two 47mm lengths of 10mm tube(i used alloy tube but steel would be o.k).
to bolt the t.b's together cut two lengths of m5 threaded bar long enough to pass through the two t.b mounting lugs and the 47mm spacers with enough protruding for an m5 nut on either end
like this
as you can see in the picture i used a remote idle adjusting screw (i used one from a spare set of zxr750-zx7 ninja carbs i have).
to do this i drilled and tapped t.b1 to line-up with the stop on the linkage
once you have set the correct spacing of the t.b's you will need to couple the butterfly linkages together (it is important the coupling does not flex otherwise accurate sync cannot be achieved).
i did this by cutting a suitable length of 10mm steel tube then squashed the ends flat, i drilled a m4 hole in one end and also in t.b1 linkage then bolted them together the other end goes between the t.b balancing screw and spring.
next i relocated the throttle cable bracket from t.b2 to t.b1
i snipped the t.p.s electrical connector plug from t.b3 and the bonneville t.p.s connector plug from the wiring loom and replaced them with a 3way ampseal connector.
the wires are connected like this:-
daytona tps - bonneville loom
blue - pink
yellow - green/yellow
black - pink/black
i modified the daytona675 fuel injector electrical sockets next to accept the mini-timer connectors i used (if you can get the daytona injector harness you do not need to do this next bit)
the locating lugs on the sides of the injector electrical socket need to be trimmed like this