There are two different weber setups for a-series spridgets, down draft, and
side draft. I have not tried the down draft. I understand this carb is a
progressive two barrel carb, with a primary & mechanical secondary. This
setup is more for fuel economy & simplicity, a little better low end torque,
and faster throttle response due to having a true accellerator pump, but
less high rpm potential than the SU's being replaced. Really, the down
draft doesn't need any calibration, and performs adequately out of the box.
The side draft DCOE option is more performance oriented. There are two
different DCOE sizes used on A-series engines, either a 40 or 45mm. For all
out racing & high RPM use, the 45 is the better choice, but will result in a
loss of low end torque due to poor airflow speed at low rpm, and has a
reputation for a throttle tip-in flat spot down low. The DCOE 40 only gives
up alittle top end hp to the 45, but it resolves the issue of the flat spot
at low rpm. Ordered new, they will come pretty well calibrated out of the
box for a stock to mild 1275. I have never found any need to modify my DCOE
40 from the way it came, and it has performed flawlessly for over 10 years.
Both of the side draft models are more thirsty than SU's, but there is a
large gain in hp that far outweighs the loss in fuel economy. I am
averaging 20 mpg city/ 30 hwy with a 1275, mild engine mods, header & DCOE
40.
----- Original Message -----
From <KrkLH at cs.com>
To: <spridgets@autox.team.net>
Sent: Friday, December 03, 2004 11:17 AM
Subject: Mini Mania Pump Question
>
> Another question. Should I eventually go to a Weber set up? I hear that
> they are much more effecient but that they are also a real hassle to get
> them
> dialed in.
>
> The oil in an SU serves to keep the piston from moving too fast, sort of a
> delay type thing. In essence, it serves as a backhanded method of keeping
> the
> fuel mix rich under acceleration - sort of a reverse exellerator pump?
> Does
> anyone run a lighter weight of oil in these carbs to improve performance.
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