Hello Al, That is a good question. The Mikuni carbs for the 67.5 2000 were
known as the type 2 carbs. They never made a type 1 for the Datsun
Roadster. The 67.5 2000 originally was equipped with a type 2 Solex Mikuni
carb and then in subsequent years they went to the type 3 and 4 carbs. The
type 3 and 4 carbs are a better designed carb for various reasons and were
used on 510's, Z cars and other Datsuns. The type 2 carbs had a totally
different clocking on the throttle shaft than the type 3 and 4 carbs. The
linkage is also very different from the type 3 or type 4 carbs. The type 2
carbs have an internal float adjustment and the type 3 and 4 carbs have an
external float adjustment.
One of the common things with these linkages is that when you place a
modified linkage on your car that it does not have the throttle stop.
Without the throttle stop the throttle shaft allows the butterfly to go past
the wide open point and then rather than allowing a good air fuel mix you
are restricting it due to decreased air flow. The throttle stop allows the
carb to stop at the 90 degree position so that the butterfly valve stays
wide open at full throttle. With a linkage with no throttle stop you
basically get is a significant reduction in performance because you are
restricting your carbs from breathing properly by letting them go past the
halfway point. In addition it may be difficult to adjust (jet) your carbs
appropriately if you don't have the correct linkage assembly I am going to
try to post some pictures on my website in the next couple of days with the
two linkages side by side.
Thanks, Gerardo Magana
P.S. I forwarded this to the list as it is a good piece of information.
Subject: RE: 67.5 2000 Solex Linkage assembly
Great idea....Quick question...I have a set of Mikuni that have the
flycut on the throttle shafts are at 45 degrees and not the horizontal
cuts for the linkage set up for the original sets early or 68 and newer..
can the linkage that your reproducing have the slot for the throttle shafts
adjusted so they fit the other types and give a correct set up for the
linkage to the cable..
thanks
Al 68 solex
Ottawa Ontario...
|