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Re: Zenith Carbs - Jetting

To: "Jarrid Gross" <JGross@econolite.com>,
Subject: Re: Zenith Carbs - Jetting
From: "Louis & Laila" <bwana@c2i2.com>
Date: Tue, 2 Oct 2001 15:52:36 -0700
You might also want to check the compression, because, depending on your
engine, that compression seems mighty low. Lou
----- Original Message -----
From: "Jarrid Gross" <JGross@econolite.com>
To: "Raser, Jason" <RaserJ@Pfizer.com>; <alpines@autox.team.net>
Sent: Tuesday, October 02, 2001 8:39 AM
Subject: RE: Zenith Carbs - Jetting


> Jason,
>
> You didnt mention what the main jets are/were.
> These, and the choke "venturi" side are the things
> that effect the running/power mixture not the pump
> discharge nozzle, and idle tube/ jet.
> The chokes are marked with a number, but could
> possibly be measured in the carb. The chokes run
> from 27mm to 30mm for the special tuning option
> offered by rootes.
>
> Also, some carbs are jeted for paper ellement filter,
> and some are jetted for bird catchers, running paper
> ellement filters with carbs setup for the bird cather
> will tend to run rather rich due to the restricivity
> of the filters.
>
> In the sunbeam alpine I-IV, there is a table in the zenith
> WIA/WIP section that describes the jets, air bleeds and
> chokes for all zenith applications.
>
> Hope this helps,
>
> Jarrid Gross
>
> -----Original Message-----
> From: owner-alpines@autox.team.net
> [mailto:owner-alpines@autox.team.net]On Behalf Of Raser, Jason
> Sent: Tuesday, October 02, 2001 6:32 AM
> To: alpines@autox.team.net
> Subject: Zenith Carbs - Jetting
>
>
> You may recall I have a Series 2 that doesn't seem to run right.  I think
> I'm getting close to a solution.
>
> I think I have eliminated all other possibile problems and everything
points
> to my Zenith Carbs.  Scott was kind enough to send me the article "To carb
> and Alpine."
>
> Before I go ahead and rejet these carbs (they are NOS, so I've done all I
> can to avoid opening them) I wonder if anyone has the experience I've had
or
> if you could direct me to the most knowlegeable person about jets for an
> Alpine.
>
> Turns out the carbs I have are:
>
> C1688F
> 36WIP-2
> 1046674
>
> and
>
> C1688R
> 36WIP-2
> 1046874
>
> The carbs I took off the car after I bought it were:
>
> C3744F
> 36WIP-3
> 1800118
>
> and
>
> C1744R
> 36WIP-3
> 1800119
>
> From the article Scott sent me I see that the differences are:
>
> Carb & Car Pump discharge Nozzle Idle Tube
> 36WIP-2 (S2) 50 50
> 36WIP-3 (S2) 70 45
>
> New parts (or rebuilt):
> Carbs
> Generator
> Distributor (45D from Moss Motors)
> Mechanical fuel pump (from Sunbeam Specialties) (I've tried an electric
pump
> too)
> New coil connected to a ballast resistor (a mechanic put this on)
> Clean fuel tank
>
> Engine compression:
> 1 120 psi
> 2 121 psi
> 3 120 psi
> 4 125 psi
>
> I put a fuel regulator after the fuel pump to ensure that I've got the
right
> fuel pressure.  I adjusted the carbs to run a bit rich and I can drive the
> car.  Runs fine on the flat spots but struggles very hard up the hills.
> Have to keep it at 3,000-4,000 rpm.
>
> I made sure my polarity on my coil is correct with the spark jumping from
> the plug toward the plug wire.  It jumps a good 1/4 inch or more.
>
> I pulled the plugs and each of them are fine black powdery, naturally
> because it's running too rich.
>
> If I simply change the pump discharge nozzle and idle tube, could this
> correct my problem by allowing me to run the carbs lean.
>
> Any ideas would be appreciated.
>
> Jason Raser

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